# Controller discussion



## Qer (May 7, 2008)

somanywelps said:


> The soliton 1 is a very respected controller, but the reason I would prefer the emotorwerks controller is the following:


And this, my dear friends, is why we won't bother with targeting the DIY-market any more; you don't get rich and you get ripped off. The main problem here, from our perspective, is that since more or less all customers are one time buyers it's hard, or rather impossible, to build a lasting business relation to them.

Since (almost) every single sale is a new business it means every sale is extremely volatile. One would think that this would be beneficial for the market, competition means the best one win etc, but it doesn't work that way. Instead it means that those that produce cheap junk and/or copy others (which means free loading on other peoples invested development time) turns out to be the winners and our main strength, long term focus on quality and duration, play a minor, neglectable, role when people shop around.

This is the reality of the DIY-market and it's not likely to change. The average DIYer is more price than quality sensitive and since we don't like that road the DIY-market is a dead end to us. We will still sell to DIYers but product development will focus on professional customers instead of hobbyists.

We've already noticed that our dedication for high quality pays off much better towards for example conversion shops than for the average DIYers, probably because they are long time customers that want a product that gives them as little headache as possible in the long run.

Oh, and good luck with regen on series wound motors. The Soliton 1 is hardware capable of regen, but there's several good reasons why it never went further than some dyno tests...


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## somanywelps (Jan 25, 2012)

Qer said:


> And this, my dear friends, is why we won't bother with targeting the DIY-market any more; you don't get rich and you get ripped off. The main problem here, from our perspective, is that since more or less all customers are one time buyers it's hard, or rather impossible, to build a lasting business relation to them.
> 
> Since (almost) every single sale is a new business it means every sale is extremely volatile. One would think that this would be beneficial for the market, competition means the best one win etc, but it doesn't work that way. Instead it means that those that produce cheap junk and/or copy others (which means free loading on other peoples invested development time) turns out to be the winners and our main strength, long term focus on quality and duration, play a minor, neglectable, role when people shop around.
> 
> ...


And that may be true. 

The emotorwerks controller appears to be functionally better in several respects. 
I'm going to be far from the first customer so I'll know if any of those promises don't fan out. 

I know you're flaming but your post meanders to the point I can't figure out what you're attacking; DIYers?


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## Batterypoweredtoad (Feb 5, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Somanywhelps: The EmotorWerks controller is functionally better in several respects or PROMISES to be better in several respects? I have a rough idea of what it costs to build a Soliton1 and I can tell you the EmotorWerks guys are not going to be making any money if they try to undercut the price and stay at the same quality. Please don't go out your way to piss off Qer and Tessarect. They built a great product that was asked for by a small market and are getting minimal financial reward. The least they have earned is respect.


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## somanywelps (Jan 25, 2012)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Batterypoweredtoad said:


> Somanywhelps: The EmotorWerks controller is functionally better in several respects or PROMISES to be better in several respects? I have a rough idea of what it costs to build a Soliton1 and I can tell you the EmotorWerks guys are not going to be making any money if they try to undercut the price and stay at the same quality. Please don't go out your way to piss off Qer and Tessarect. They built a great product that was asked for by a small market and are getting minimal financial reward. The least they have earned is respect.


I chose my words very carefully in order to not piss anyone off. Emotorwerks says their controller(functional prototype) does the list above. It's in one of their vehicles right now. 

I believe them unless proven otherwise. I am not so naive as to buy it without verifying myself, however. 

I would appreciate everyone involved refrain from personal attacks in and otherwise derailing this thread.


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## Bowser330 (Jun 15, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Can you please link me to where it discusses the Emotorwerks controller, I cannot find any details on it? I cannot find it on their website, Thanks.


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## somanywelps (Jan 25, 2012)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Bowser330 said:


> Can you please link me to where it discusses the Emotorwerks controller, I cannot find any details on it? I cannot find it on their website, Thanks.


It's briefly mentioned in their press releases. E-mail them directly for the information I provided above (the information above came from an email exchange).


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## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



efan said:


> perhaps he is doing whatever it is he is doing (I can't speculate) not to get rich but to have more flexibility, he might need a 500V 1000a controller...or he might be trying to offer to the public (including himself) a product at a more reasonable price.


Wow, I think the price point on the Soliton Jr. makes it a great deal. For only about $300 more than a Curtis 1231C you get a smart controller that can be programmed to protect your batteries and motor. You get the main contactor included. You also get the precharge system and intelligent interlocks with the 12 volt system included. The potential peak power puts the only slightly cheaper Curtis to shame, up to 2.5 times the power depending on pack voltage.

If price is everything there is always EPC controllers...


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## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



somanywelps said:


> It's briefly mentioned in their press releases. E-mail them directly for the information I provided above (the information above came from an email exchange).


And this is what I'm talking about; every single sale in the DIY-community is separate; long, faithful relations doesn't exist and what you see is only that it "appears to be functionally better", based not on hard empirical data but on a press release and "email exchange". As I said, the DIY-market is extremely volatile which makes it rather ungrateful to work on.

In the long run it makes the DIY-market unattractive from a producers point of view and I start to realise the hard way why many big companies not only don't target hobbyists but flat out refuse to do business with them all together. From being one of those that's been frustrated over that I can't buy "real" stuff I've started to understand WHY I can't buy them and why they often demand more close relations and long time commitments.



somanywelps said:


> I know you're flaming but your post meanders to the point I can't figure out what you're attacking; DIYers?


 I'm not flaming, I'm venting. There's a difference.

And I'm sorry you can't see my point of view. That kinda proves my point yet another time and convinces me even more that the decision to stop focusing on DIYers was the right one if we want to get more than Wall-Mart salaries...


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## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> Wow, I think the price point on the Soliton Jr. makes it a great deal.


Thank you. And that's the reason I, personally, don't want to leave the hobbyist market entirely. I like the kick when people do use our products and posts pics, vids and stories about their progress.


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## efan (Aug 27, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> Wow, I think the price point on the Soliton Jr. makes it a great deal. For only about $300 more than a Curtis 1231C you get a smart controller that can be programmed to protect your batteries and motor. You get the main contactor included. You also get the precharge system and intelligent interlocks with the 12 volt system included. The potential peak power puts the only slightly cheaper Curtis to shame, up to 2.5 times the power depending on pack voltage.
> 
> If price is everything there is always EPC controllers...


haha EPC controllers very funny indeed !!!
I think that the Soliton (and Shiva) controllers are great as well, but it seems that they are worried about someone copping the Soliton 1...which they should not be.
If say I was to open up a Soliton and see what components it uses and then make my own (don't worry I do not have the skills ) then I would come up with a controller that is not all that much better or cheaper...unless the Soliton 1 is somewhat overpriced in which case I come up with a controller that is as good and can also attract more customers with a more reasonable price.


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## efan (Aug 27, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> I like the kick when people do use our products and posts pics, vids and stories about their progress.


That is great for newbies who are just starting a conversion since they can see and replicate other conversions, it basically helps in choosing better components...it can be good advertisement but it seems that many conversions are done by people who do not post pictures and vids on the internet. Have you taught of offering a modest discount to your customers if they are willing to post their conversion of evalbum.com or start a thread about it on a forum? Just an idea!


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## rochesterricer (Jan 5, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> And this is what I'm talking about; every single sale in the DIY-community is separate; long, faithful relations doesn't exist and what you see is only that it "appears to be functionally better", based not on hard empirical data but on a press release and "email exchange". As I said, the DIY-market is extremely volatile which makes it rather ungrateful to work on.


I see something else in his statement. There will be some looking for something in between a Soliton and Shiva in performance. There is at least a handful of people out there looking for as many amps as possible, but can't afford to go all the way to a racing controller like the Shiva. 

I suppose that is another flaw with the DIY crowd. Everyone always wants more, but most can't afford to pay for it.


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



efan said:


> ... but it seems that they are worried about someone copping the Soliton 1...which they should not be.
> If say I was to open up a Soliton and see what components it uses and then make my own (don't worry I do not have the skills ) then I would come up with a controller that is not all that much better or cheaper...unless the Soliton 1 is somewhat overpriced in which case I come up with a controller that is as good and can also attract more customers with a more reasonable price.


Sure, as long as you assume that the time it took to develop the controller is worth absolutely nothing. This is what kills me about this argument - people only consider the parts cost, not the time it took to develop a product, nor even the labor it takes to assemble it! If you value both of those at zero (that is, if you copied my design and then built it yourself) then of course I can't compete with you... why should I even bother at that point?

The Soliton1 (etc.) costs more than the mere sum of its parts because a bucketful of those same parts doesn't do a whole lot besides take up space in a bucket. That is to say, it is the arrangement of those parts - and the code that goes inside the microcontroller - that adds real value to the product. 

We who design and make the products would like to make a reasonable profit on each one. If someone comes along and rips us off then we have a disincentive to keep designing products, simple as that. I mean, if I want to contribute to a charity I donate to the Humane Society...


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## ElectriCar (Jun 15, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

What a lot of folks don't understand about what a product or services cost is the "unseen" costs. A company doesn't just assemble parts and create software or whatever their visible operations are. It costs money for the lights to be on in a building they have to pay for, tax accounts, attorneys, transportation and fuel, liability and other insurances etc. A heck of a lot more costs go into a product than just the parts. It costs something every time someone runs an errand, gets on the phone, answers an email etc. Sure people enjoy what they do, I do, but we don't do it for the hell of it, we have to make a salary as well! 

My "hacked" Curtis as Tesseract calls it is blowing mosfets periodically which I hope to get resolved but if I don't I'm likely purchasing a Soliton1. 

And guys, I'd really love to have some type interface to go with it like another company offers for $300 so I have more info available and not need to do so much instrument hardwiring. There is only so much dash to hang things on in an S10!


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## efan (Aug 27, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> This is what kills me about this argument - people only consider the parts cost, not the time it took to develop a product, nor even the labor it takes to assemble it! If you value both of those at zero (that is, if you copied my design and then built it yourself) then of course I can't compete with you... why should I even bother at that point?


I am not saying that the development of the product is not worth anything, but it is worth a finite amount of money...I assume after having sold x-number of units you have earned whatever value you have assigned for your development...at this points if there is a competitor you can start playing competitively! 
then again I am not running a small company selling to diyers so I could be wrong.


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## MalcolmB (Jun 10, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> As I said, the DIY-market is extremely volatile which makes it rather ungrateful to work on.


Totally understand your venting, but I think there's a couple of factors you may be underestimating.

Pricing isn't the main consideration for many of us, otherwise we wouldn't be wasting our hard-earned cash on pastimes with such a poor ROI.

Many of us have engineering backgrounds and are familiar with intellectual property right issues. We respect good engineering and realise that product loyalty is a way of making the sure the gooduns keep on coming up with good stuff.

We may be one-off customers and we may appear ungrateful, but as a result of our mutual obsession we tend to become local "experts" (for want of a better word), and we recommend the products we know to be reliable to other initiates in the DIY fraternity.

Having said that, I know that dealing with customers can be a real pain in the arse. They ask stupid questions, they want every imaginable feature under the sun, they ignore your advice and then they do totally bizarre and unpredictable things with your carefully crafted product and want to know why you didn't foresee the ensuing problem...

Personally I'd see it as a big loss for self-builders if you turn away from the DIY market. I have a feeling this market will really start taking off in the next few years. Obviously you need to decide where you want to go with your business – whether DIY or OEM offer the best opportunity to achieve your own goals.

Oh, and while I'm at it, I may as well add my vote for a bluetooth/Android interface for Soliton, pleeease


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## palmer_md (Jul 22, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Well said Malcolm. +1


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## PhantomPholly (Aug 20, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



efan said:


> I am not saying that the development of the product is not worth anything, but it is worth a finite amount of money...I assume after having sold x-number of units you have earned whatever value you have assigned for your development...at this points if there is a competitor you can start playing competitively!
> then again I am not running a small company selling to diyers so I could be wrong.


The question always comes down to, "Who decides how much money a person's time is worth?"

Unless he is a slave, it is up to him and him alone to decide what to value his time and the products of his work at. If you disagree with his valuation, you are free not to purchase his product, or to offer a lower price (which he may or may not take). If he doesn't sell any products, that "feedback" may persuade him to reduce his valuation. Or not, in which case he's stuck with whatever he made until and unless he finds people willing to pay his price. This "negotiation between many buyers" process is called "supply and demand," and no one has figured out a better way to maximize both our freedoms and our prosperity.


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## DavidDymaxion (Dec 1, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Hang in there, Qer!

FWIW, I have purchased my EV components from either local suppliers (I can see their operation is real) or from folks that are a known, stable quantity online (like Manzanita Micro). I pay a bit more to do it this way, but so far all my equipment has worked to spec. I do appreciate all of the shared expertise of you and your coworkers -- that plus the good user reports puts the Soliton on my short list if I go series on a future conversion.


Qer said:


> And this is what I'm talking about; every single sale in the DIY-community is separate; long, faithful relations doesn't exist and what you see is only that it "appears to be functionally better", based not on hard empirical data but on a press release and "email exchange". As I said, the DIY-market is extremely volatile which makes it rather ungrateful to work on.
> 
> In the long run it makes the DIY-market unattractive from a producers point of view and I start to realise the hard way why many big companies not only don't target hobbyists but flat out refuse to do business with them all together. From being one of those that's been frustrated over that I can't buy "real" stuff I've started to understand WHY I can't buy them and why they often demand more close relations and long time commitments. ...


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## Amberwolf (May 29, 2009)

I have to agree with Qer/Tesseract, and PhantomPholly explains it well. 

The main reason I spend most of my worktime working in a retail pet store is because even though I get less than $10/hour there, and not even 30 hours a week, I still make more than when I did computer repair, jack-of-all-trades-type repair, built custom sci-fi props and models for the sci-fi convention crowd, or when I did 3D artwork, or music. 

Most of the people that wanted my services complained that they could do it themselves really cheap or free, and sure, they could--because they are valuing their own time at zero. Some were willing to pay the asking prices, but not most. Some even cheated me by agreeing to the price then after the work was done refused to pay me the agreed price, offering what amounted to a couple of dollars an hour.  It's not like I charged a fortune for any of my work--I was probably less than most anyone else out there. Still, it was too much for most. 


So I don't do any of that anymore, except for certain people that I know value my time. Some of them I'll even do it for nothing or nearly so, just because I value their time as much as they do mine, and we're friends. But mostly, I just don't bother now. I'd rather spend my limited time with my rescued dogs and on my own personal projects, of which there are already too many to ever finish.  (and on helping out over on Endless-Sphere as much as I'm able...I'd do it here, too but I know too little about the car side of things).


On the flip side, I don't even have enough money most of the time to do more than barely stay afloat, and I'm an extremely frugal person. So I most defintely do all the DIY I can, and usually end up getting other people's discarded broken things to fix up to use myself rather than buying anything new, just so I *can* keep my projects going, like CrazyBike2 and DayGlo Avenger, among others. So I also wish all things were open-source, so that those that wanted to could build their own from scratch, or modify it to suit their own needs, without having to start literally from scratch. I just realize that not everyone can afford to throw their time away like that, and are trying to create something to make a business to live on. 


I definitely understand perfectly where Qer and Tesseract and others are coming from, on both sides of the discussion.


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## Woodsmith (Jun 5, 2008)

I know what you mean, Amberwolf.

When I was making furniture I found that there were the poor ordinary working person who valued my time and would save up for the price I gave and then commission when they had the money.
Then there were the wealthy clients who would ask the world and then knock random amounts off the price, just because they think they can, leaving me with no profit and barely any labour charge.

I have no money to spare but I do value the work that goes into the design and creation of a thing.

If I had the opportunity to raise the funds I would buy a Soliton based on what I have read on this forum. However, it is likely that I will either use a second hand Curtis or build open source, not because I think they are as good or better but because I wouldn't want to cause insult by asking for a 'cheapened' Soliton.

I can see what Qer is saying. 
Often I have thought of never working for wealthy clients again because of the lack of reward, appreciation and repeat business (either because they only try ripping me off once or I vow never to work for them again).


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## Ace_bridger (Nov 22, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



MalcolmB said:


> Totally understand your venting, but I think there's a couple of factors you may be underestimating.
> 
> Pricing isn't the main consideration for many of us, otherwise we wouldn't be wasting our hard-earned cash on pastimes with such a poor ROI.
> 
> Many of us have engineering backgrounds and are familiar with intellectual property right issues. We respect good engineering and realise that product loyalty is a way of making the sure the gooduns keep on coming up with good stuff.


Well done Malcom, +2.


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## Yukon_Shane (Jul 15, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



MalcolmB said:


> Totally understand your venting, but I think there's a couple of factors you may be underestimating.
> 
> Pricing isn't the main consideration for many of us, otherwise we wouldn't be wasting our hard-earned cash on pastimes with such a poor ROI.
> 
> ...


 
+3 Well written and captures my thoughts as well.


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



MalcolmB said:


> Personally I'd see it as a big loss for self-builders if you turn away from the DIY market. I have a feeling this market will really start taking off in the next few years. Obviously you need to decide where you want to go with your business – whether DIY or OEM offer the best opportunity to achieve your own goals.


Oh, we're not going to stop selling to DIYers, we're just not going to design products specifically for them anymore. That is to say, our future products will be designed with the commercial/professional end-market in mind, with a particular emphasis on passing EMC and safety regulations in both the EU (where such is enforced regardless of whether the customer cares or not) and the US (where the DIYer need not care about such at all). The fact of the matter is that if this market does, indeed, take off in the next few years, then you can bet that the existing safety and EMC standards will be enforced more widely and with more consistency than they are now, all but eliminating any non-compliant products from the market.

Sadly for the DIYer, making products so they will comply with EMC and safety regulations often adds a considerable cost while delivering very little apparent benefit to the end user. After all, the customer won't care if a motor controller or charger obliterates reception on any nearby AM radio if the customer never listens to AM radio!




MalcolmB said:


> Oh, and while I'm at it, I may as well add my vote for a bluetooth/Android interface for Soliton, pleeease


I'm not sure what you are asking for here... do you want a bluetooth/android interface *inside* the controller - that's not going to work too well given that our controllers are fully shielded by virtue of their machined aluminum housings! Or do you want an external ethernet to bluetooth bridge that talks to an Android tablet? Or??? What?


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## MalcolmB (Jun 10, 2008)

Designing for compliance with EMC standards obviously makes good business sense, though as you say, from a purely DIY standpoint it adds no real value. I guess in a few years' time we'll be longing for the 'good old days' when we didn't have to worry about such trivialities.



> Or do you want an external ethernet to bluetooth bridge that talks to an Android tablet?


It was mostly tongue-in-cheek, but yes, like ElectriCar suggested earlier, an external unit that gives access to information from the controller such as battery current, motor current, rpm, even system efficiency. I know some of this can already be done with a wireless router and the EV Speedo app, and maybe that can be just as convenient as the Bluetooth option? It would add a lot of value if we could eliminate any changes to the dash and just use a tablet for instrumentation, but I'm just starting to get to grips with the different options.

(Edit: you obviously can't measure system efficiency from the controller – just proving my point about customers asking stupid questions...)


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## Yukon_Shane (Jul 15, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Oh, we're not going to stop selling to DIYers, we're just not going to design products specifically for them anymore. That is to say, our future products will be designed with the commercial/professional end-market in mind, with a particular emphasis on passing EMC and safety regulations in both the EU (where such is enforced regardless of whether the customer cares or not) and the US (where the DIYer need not care about such at all). The fact of the matter is that if this market does, indeed, take off in the next few years, then you can bet that the existing safety and EMC standards will be enforced more widely and with more consistency than they are now, all but eliminating any non-compliant products from the market.
> 
> Sadly for the DIYer, making products so they will comply with EMC and safety regulations often adds a considerable cost while delivering very little apparent benefit to the end user. After all, the customer won't care if a motor controller or charger obliterates reception on any nearby AM radio if the customer never listens to AM radio!


When you say "commercial/professional end-market" are you meaning the electrical vehicle conversion market or are you talking about branching into a different electric motor controls area?

I'm curious because, from the little I've seen, the "professional" conversion market seems to pretty much consist of DIY guys with dreams of making a living in their hobby (converting cars). Is there anyone out there really doing well converting electric vehicles as a business?

For me there is no doubt that the Evnetics controller is the best DC controller on the market (that's why I bought one). It's clear to me that the focus of the Evnetics staff is on producing a quality product first and foremost before any other considerations and I applaud your efforts to continue to make a "better mousetrap".

I don't know if making your products comply with EMC and Safety regulations will help sell controller but I think it should and I hope it does.


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## JRoque (Mar 9, 2010)

Hi. Hmm I guess I missed the original announcement about Evnetics' change in direction. It sounds like you guys will end up like Curtis with main source of revenue from enterprise/industrial customers and have a VAR, like HPEVs is to Curtis. I think it makes perfect sense for something like that. Best wishes.

JR
PS: so no AC controller then?


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## palmer_md (Jul 22, 2011)

JRoque said:


> PS: so no AC controller then?


just a WAG, but I'd guess quite the opposite, and that AC is the direction that they will take with the "new product line" that was discussed elsewhere...cant find it now to link.


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## Batterypoweredtoad (Feb 5, 2008)

palmer_md said:


> just a WAG, but I'd guess quite the opposite, and that AC is the direction that they will take with the "new product line" that was discussed elsewhere...cant find it now to link.


Yep, I would say AC as well. My guess would be all the components to build a complete AC system in the 150 hp or greater range. The only companies you regularly see getting factory contracts or fleet contracts are selling complete AC systems and they are selling them for big bucks. I think it would be awesome to have those available, but I am guessing the mention of "not targeting hobbyists" really means "Expensive". I would guess less expensive than the higher powered AC systems currently available, but certainly not 70hp curtis AC system prices.


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



MalcolmB said:


> ... an external unit that gives access to information from the controller such as battery current, motor current, rpm, even [some bogus metric that can't be measured]


I don't know what you Brits call such a magical contraption, but on this side of the pond we call such an "external unit" a *laptop*... 

Ok, more seriously, yes, all of the data you you want to monitor is continuously streamed to the ethernet port on our controllers and we even provide the protocol description of said data openly, so anyone so inclined should be able to create a much nicer dashboard app than runty old logger.exe.




Yukon_Shane said:


> I'm curious because, from the little I've seen, the "professional" conversion market seems to pretty much consist of DIY guys with dreams of making a living in their hobby (converting cars). Is there anyone out there really doing well converting electric vehicles as a business?


I tend to agree with your opinion that most conversion shops are basically DIYers with extra ambition, but our controllers are already designed specifically for these guys, so no, not them... 

Am I being obtuse? Somewhat, yes, but you are asking me to tell the world our plans for the future and that ain't gonna happen. Don't care if you buy a Shiva, I still ain't tellin'.



Yukon_Shane said:


> For me there is no doubt that the Evnetics controller is the best DC controller on the market (that's why I bought one). It's clear to me that the focus of the Evnetics staff is on producing a quality product first and foremost before any other considerations and I applaud your efforts to continue to make a "better mousetrap".


Thanks! One comment like this is enough to offset at least 10 tech support emails complaining about something that is covered in the manual...


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## Tesseract (Sep 27, 2008)

palmer_md said:


> just a WAG, but I'd guess quite the opposite, and that AC is the direction that they will take with the "new product line" that was discussed elsewhere...cant find it now to link.


Apparently Seb let slip to Jack Rickard that Qer and me are currently working on a "new product line" which is not exactly accurate.

We are certainly going to *eventually* develop an AC inverter, but there is much low-hanging fruit to pick first (like, e.g., turning our DC controllers into rapid chargers). The sad truth is that we don't sell nearly enough "stuff" to be able to fund such a costly endeavor through cash flow alone, and trying to get funding - even as a "green" company that makes actual products, that actual people can actually buy!? - does not seem to count in our favor at all.

Thus, no soup for you.


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## ElectriCar (Jun 15, 2008)

I'd like to help you out and get a Soliton1 but just can't bring myself to spend that much money. Your supply of controllers exceeds my supply of $$$.


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## TigerNut (Dec 18, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Oh, we're not going to stop selling to DIYers, we're just not going to design products specifically for them anymore. That is to say, our future products will be designed with the commercial/professional end-market in mind, with a particular emphasis on passing EMC and safety regulations in both the EU (where such is enforced regardless of whether the customer cares or not) and the US (where the DIYer need not care about such at all). The fact of the matter is that if this market does, indeed, take off in the next few years, then you can bet that the existing safety and EMC standards will be enforced more widely and with more consistency than they are now, all but eliminating any non-compliant products from the market.
> 
> Sadly for the DIYer, making products so they will comply with EMC and safety regulations often adds a considerable cost while delivering very little apparent benefit to the end user. After all, the customer won't care if a motor controller or charger obliterates reception on any nearby AM radio if the customer never listens to AM radio!


+1. I build tachometer boards and instrument voltage regulators for old-school British cars, and while there is no EMC compliance problem with these, putting in enough protection so that the circuits don't get fried due to all the possible bad things that can be inflicted on a car's electrical system, doubles the component count and triples the cost of the components.
EMC and RFI compliance (as well as appropriate safety-oriented current/voltage limiting) is something that a lot of people don't care about unless they get hit with a problem... but adding EMI and RFI suppression, or intrinsically-safe protection, is much harder than designing it in from the beginning. 
So props for taking the high road.


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## piotrsko (Dec 9, 2007)

Do you over at EVnetics ever think of Grant money and acquisition thereof? There are non-government grants available.

I'd like to think all my questions are somewhat different and mentally stimulating. However Tess may think otherwise.


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## JRP3 (Mar 7, 2008)

Batterypoweredtoad said:


> Yep, I would say AC as well. My guess would be all the components to build a complete AC system in the 150 hp or greater range. The only companies you regularly see getting factory contracts or fleet contracts are selling complete AC systems and they are selling them for big bucks. I think it would be awesome to have those available, but I am guessing the mention of "not targeting hobbyists" really means "Expensive". I would guess less expensive than the higher powered AC systems currently available, but certainly not 70hp curtis AC system prices.


I'm pretty sure the only way we are going to get affordable higher power AC units is when OEM cars start hitting the junk yards in volume, about 10-15 years from now.


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## Qer (May 7, 2008)

JRP3 said:


> I'm pretty sure the only way we are going to get affordable higher power AC units is when OEM cars start hitting the junk yards in volume, about 10-15 years from now.


Yep, I think you're spot on there. After all, that's why most people use series wound motors and why they've ended up the DIY-norm today; old scrapped fork lifts that people could strip. Then you, of course, also have the problem that a series wound motor and controller don't have to be matched while the AC motor and inverter has. AC systems will continue to be overprised and/or underpowered for quite some time and an evnetics AC inverter wouldn't be different in that aspect.

After all, there's more of everything in an AC inverter; more silicon, more losses, more computing power, more software, more problems...


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## steven4601 (Nov 11, 2010)

Fair is fair, the EVNetics controller really deserves a crown regarding performance. price & availability.

AC setup pricing,, as with almost everything, it all comes down to production scale. AC motors have been around a long time. The industrial versions are cheapish. Their automotive versions with their packaging makes them expensive for the DIYer at this moment due low availability.


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## Batterypoweredtoad (Feb 5, 2008)

Obviously Qer and Tess know more about what they are going to make than I do so I stand corrected about my guess. I do have to ask though: couldn't an AC controller be made to compete with the big dog AC propulsion types for a lower price point? If it truly is 3x the cost that would still put a Soliton 1 level controller sub $10k. IIRC the higher powered AC setups out there are closer to $30k than $20k. Combine the newly crowned Tri-Sol with one of the Remy motors Tess was interested in a while back and you could crush the competitors in price and performance. Then the next time a company wants to do something like the Mini-E they could come to you guys.


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



TigerNut said:


> +1. I build tachometer boards and instrument voltage regulators for old-school British cars,


What? The old stuttering relay generator field current regulator isn't good enough for you?!? 



TigerNut said:


> ...but adding EMI and RFI suppression, or intrinsically-safe protection, is much harder than designing it in from the beginning.
> So props for taking the high road.


Aye, while I used good engineering practices in general to design the Soliton hardware, I did not specifically attempt to comply with any EMC* or safety regulations because I noticed that none of the competition - former, future or even zombie** - bothered to do so. Indeed, with so much of the competition using plastic end caps and protruding bus bars, there was no way any of them could be made compliant anyway. That said, we did manage to get through EMC testing without too much kludging of the internals, and merely adding plastic covers for the bulkhead terminals got us through testing for ECE-R100 (safety), but I'll be the first to admit this was clearly a case of "it's better to be lucky than good".


* EMC = ElectroMagnetic Compatibility
** - like Zilla, which has come back from the dead twice!


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## Tesseract (Sep 27, 2008)

piotrsko said:


> Do you over at EVnetics ever think of Grant money and acquisition thereof? There are non-government grants available.


As I often say to Seb whenever he forwards yet another wacky feature or product request email my way, I have a limited number of hours that I can spend working, so choose how to utilize them wisely. In my experience, getting a grant of any kind requires a lot of work, with even less assurance of success than designing a new product, so the risk/reward metric looks pretty unfavorable to me, but if you know of any grants in particular you think we should go for then by all means PM the details to me... Who can turn down (almost) free money???


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## Tesseract (Sep 27, 2008)

Batterypoweredtoad said:


> ..I do have to ask though: couldn't an AC controller be made to compete with the big dog AC propulsion types for a lower price point? If it truly is 3x the cost that would still put a Soliton 1 level controller sub $10k.


You are making the common, but incorrect assumption that it is only the cost of the hardware that is relevant to the price of the inverter. If that were the only concern then I could make a ~200kW inverter for about twice the cost of a Soliton1, rather than 3x; it's developing the control software that is so difficult and adds so much to the final price. I'm not justifying the price of the inverters made by, e.g., AC Propulsion, or even of Sevcon or Rhinehart Motion, I'm just saying that the development cost of the control software must be paid for with a higher product of price times unit sales volume.

That is to say, if it costs $1M to develop an inverter and $2000 to build one, you can sell 500 at $4000 just to pay off the development cost, or 50 at $22,000; AC Propulsion seems to have chosen the latter route, and to speculate even further, probably because they don't think they would sell more than 50 inverters per year (not so wild a speculation, actually).

Dropping the price of their inverter to $4000, where they (e.g.) only make a gross profit of $2000 per inverter, might very well result in a huge increase in sales volume, but unless the product of volume * profit is higher than before they won't pay back their development cost any faster, but they will have to work harder (after all, it is more work to build 500 inverters - and deal with that many more customers - than it is to just build 50 of them).

I'm not trying to be unduly pessimistic, rather, I'm just providing a more manufacturing-oriented perspective to the discussion.


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## jddcircuit (Mar 18, 2010)

JRP3 said:


> I'm pretty sure the only way we are going to get affordable higher power AC units is when OEM cars start hitting the junk yards in volume, about 10-15 years from now.


I don't think it is 10-15years from now but I do agree that it is where the future of conversion hardware is going to come from. That is why I am tinkering with a Prius transaxle that I got free from a local transmission shop and a Prius inverter I got for $100 on ebay. The price was right.

These transaxles are readily available on ebay for $300 to $700 from what I see.

I have been able to get the motor to spin pretty good with a couple of different micro controllers using some very basic code. It pushed my car around the block using 48v of near dead lead acid batteries.

I am now working on my battery management system before getting back on the motor control. The inverter hardware can also act as a boost converter for charging my new batter pack with the proper control.

To get the most out this motor and inverter it seems I will have to develop more sophisticated software algorithm. Producing the Max Torque for Min Current for this motor is an interesting project. It is not like controlling a standard BLDC motor.


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## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> ** - like Zilla, which has come back from the dead twice!


Risen from the dead twice? You make the Zilla sound better than Jesus -- and that's just not right! 

I'm thinking about selling my Zilla Z1k-LV and buying a Soliton Jr. to try out. I just swapped my Zilla HV with series/parallel and forward/reverse shifting controls into the buggy to free up the LV. I turned the Zilla down to 600 battery amps to make sure I was comfortable with the decrease in low rpm torque.  It's fine, little less spunky from 0-15 mph when I take off in 3rd gear. 

So far I have used a Curtis 1221B, DC Power Systems Raptor 450, and Zilla Z1k. I haven't used an Auburn Scientific controller, but it's a little late for that now. I haven't used an Evnetics controller yet and they don't seem very common on the west coast. I haven't seen one in person.


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## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I'm thinking about selling my Zilla Z1k-LV and buying a Soliton Jr. to try out.


Something I'd find very interesting would be if you'd do an A/B-test of the Z1K and Jr. and write a post here of pros and cons, in what way the controllers behave similar and where they differ and so on.

I think it would be very interesting, for example to get input on what could be done better.

Pretty please with sugar on top?


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## JRoque (Mar 9, 2010)

I have an improvement suggestion for one of these:

1. Make it available for sale

JR


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## Tesseract (Sep 27, 2008)

JRoque said:


> I have an improvement suggestion for one of these:
> 
> 1. Make it available for sale
> 
> JR


Make what available for sale?!? No antecedent to either of your two pronouns! *Thwack* goes the nun's ruler.


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> Risen from the dead twice? You make the Zilla sound better than Jesus -- and that's just not right!


Well, how many other products can you think of that got killed off twice but still came back from the dead?!? 



EVfun said:


> I'm thinking about selling my Zilla Z1k-LV and buying a Soliton Jr. to try out.


Yes, Luke... Come to the darkside... also, did I mention we have cookies over here? 



EVfun said:


> So far I have used a Curtis 1221B, DC Power Systems Raptor 450, and Zilla Z1k. I haven't used an Auburn Scientific controller, but it's a little late for that now....


Yep, both because they went out of business and the electrolytic capacitors inside one ain't exactly spring chickens anymore...



EVfun said:


> I haven't used an Evnetics controller yet and they don't seem very common on the west coast. I haven't seen one in person.


Curious, isn't it? Ah well, the cookies will tempt them all eventually...


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## JRoque (Mar 9, 2010)

Tesseract said:


> Make what available for sale?!? No antecedent to either of your two pronouns! *Thwack* goes the nun's ruler.


Dear Sister Mary, I was answering Qer's:



Qer said:


> I think it would be very interesting, for example to get input on what could be done better.


I started the list by suggesting one of the two controllers could be improved by making them actually available for sale. If you can order Juniors right now, you are very close to answering the question of which one I'm referring to. Take your time.... 

JR


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## Tesseract (Sep 27, 2008)

JRoque said:


> ...I started the list by suggesting one of the two controllers could be improved by making them actually available for sale. If you can order Juniors right now, you are very close to answering the question of which one I'm referring to. Take your time....
> 
> JR


Well that's why I was confused, then, because the Junior _is_ available - has been for about a year, actually - and I *thought* the Z1K-LV was once again available, too - that is, my understanding is that Manzanita Micro took over production of the entire Zilla line.


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## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Yep, both because they went out of business and the electrolytic capacitors inside one ain't exactly spring chickens anymore...


You seem to think electrolytic capacitors are a big deal, but I took a perfectly working old Curtis 1221B controller out of my buggy back in 2010. It was used when I bought it in 1999. I understand electrolytic capacitors have a life span and will fail in time, but it doesn't seem to happen soon. Heck, the caps in my controller where almost always charged to full pack voltage because my precharge circuit was just a light bulb across the main contactor and a ksi relay.

It would be a lot more helpful, and convincing, if you spent less time attacking the problems you perceive in your competitors products and more time explaining the strengths of your products. Please tell me what yours will do for me, not what your competitors won't do for me. I've likely used your competitors offerings.


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## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I understand electrolytic capacitors have a life span and will fail in time, but it doesn't seem to happen soon.


That's because they fail gradually and you might not notice it until you start to stress the caps. It's possible an old 1221B isn't really stressful for the caps. 

Hi, old audiophile here (mostly recovered though). I've lost track of how many old caps I've replaced in mainly amplifiers. The typical tendency of old caps (as I've seen it from an audiophile perspective) is that leakage current goes up with age. This means that the rectified DC starts to get a higher AC-part over time until you can start to hear it in the speakers.

The slowly increasing current also means that the caps are starting to heat up when powered, which will increase the degradation and in extreme cases it can end with the caps starting to boil and finally that they explode like an overheated pressure cooker. Bam! Capacitor intestines all over the place. Been there, done that, messy as hell...

A ten year old cap isn't pristine but depending on how stressed it is it can still be going strong for a decade or two or it can be so bad that a hard acceleration (with maximum ripple current) will be the final nail in the coffin and you'll have to get a friend to tow you home.

The only way I can think of is to check if the controller starts to feel unnaturally warm when left powered up but unused. If it starts to feel warm to the touch just by being powered I'd say that the caps are close to expiring and that replacing them might be a good idea before the controller let loose the huge 4th of July-party all by itself.

Although, this is experiences based mainly on audio equipment. Those high voltage high current scenarios seems a lot more tricky than old, cosy amplifiers...


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> You seem to think electrolytic capacitors are a big deal, but I took a perfectly working old Curtis 1221B controller out of my buggy back in 2010. It was used when I bought it in 1999. I understand electrolytic capacitors have a life span and will fail in time, but it doesn't seem to happen soon. Heck, the caps in my controller where almost always charged to full pack voltage because my precharge circuit was just a light bulb across the main contactor and a ksi relay.


Yeah, I make a big deal about it because the electrolytic capacitor is the only component besides the vacuum tube that is guaranteed to go bad from just sitting around doing nothing. Not even a fuse has that problem.

The deal here is that every motor controller that uses electrolytics has made a Faustian bargain with them: by assuming that the ambient temperature will be much cooler than the max permitted (e.g., 105C), ripple current can be pushed much higher because *EV* motor controllers need more ripple current than they do 10kh+ lifespans. Of course, only in an on-road EV application - preferably with lead-acid batteries - can you make the corollary assumption that the motor controller will only be used ~30m every day so that the resulting 1000-4000 hours of operating life doesn't seem pitifully short.



EVfun said:


> It would be a lot more helpful, and convincing, if you spent less time attacking the problems you perceive in your competitors products and more time explaining the strengths of your products. Please tell me what yours will do for me, not what your competitors won't do for me. I've likely used your competitors offerings.


Somehow I doubt that me writing a sales spiel is going to sway you one way or the other.. That said, I strongly disagree with your premise that I spend much of my time attacking the perceived weaknesses of my competitors in the first place. On the contrary, I don't spend any time attacking them, even indirectly. When I make a comment about electrolytic capacitors going bad over time, I'm not taking a jab at my competitors, I'm merely stating something that all power electronics engineers know to be true from *painful experience*.

You should pick whichever controller you think offers the best blend of performance, reliability and features for the money. Based on those criteria alone, that means you should keep your existing Zilla - after all, why spend money on a new controller if your old one works perfectly fine?


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> ....The only way I can think of is to check if the controller starts to feel unnaturally warm when left powered up but unused. If it starts to feel warm to the touch just by being powered I'd say that the caps are close to expiring and that replacing them might be a good idea before the controller let loose the huge 4th of July-party all by itself.


Nope - this trick only works for mains-powered equipment because the 50/100Hz or 60/120Hz ripple from the rectifier causes heating across the every-increasing ESR (which is the main symptom of elkos* going bad; increasing leakage is another symptom which is less relevant to the power supply, but hugely important in coupling applications).

Thus, the only warning bad elkos in a motor controller will give you is when they explode...



* - elkos is the diminutive for "aluminum electrolytic capacitors" preferred by Europeans; used out of deference to Qer's Swedish nationality.


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## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> Something I'd find very interesting would be if you'd do an A/B-test of the Z1K and Jr. and write a post here of pros and cons, in what way the controllers behave similar and where they differ and so on.
> 
> I think it would be very interesting, for example to get input on what could be done better.
> 
> Pretty please with sugar on top?


I found one person locally with a Soliton 1 so I can at least get some first hand impressions before making the decision. Mr. T (Tesseract) seems to think I should just keep the Zilla. 

I have been curious, how is ripple current on the battery loop controlled without the usual large capacity capacitor bank? Large high frequency ripple current on the battery loop isn't good for wire losses and would typically be bad for radiated RF too. From what I understand the Soliton passes European testing in that department.


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## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I have been curious, how is ripple current on the battery loop controlled without the usual large capacity capacitor bank?


This seems to be a good read.

http://www.badcaps.net/forum/showthread.php?t=1458


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I found one person locally with a Soliton 1 so I can at least get some first hand impressions before making the decision. Mr. T (Tesseract) seems to think I should just keep the Zilla.


Well, the Zilla is a good controller so assuming you are happy with it - and by all accounts you are - then why get rid of it. Unless, of course, you are one of those incorrigible tinkerers that can't leave well enough alone, in which case you should change controllers every few months or so.



EVfun said:


> I have been curious, how is ripple current on the battery loop controlled without the usual large capacity capacitor bank?
> Large high frequency ripple current on the battery loop isn't good for wire losses and would typically be bad for radiated RF too. From what I understand the Soliton passes European testing in that department.


The input capacitor of the buck converter integrates the rectangular current waveform drawn by the switch into a triangular waveform which the impedance of the supply wiring converts into what is called the reflected ripple voltage.

Thus the inductance and resistance of the battery loop wiring affects the level of observed ripple voltage. If the impedance of this loop is too high then the controller won't operate correctly, but that would be true _regardless of the amount of capacitance present!


_


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## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> The input capacitor of the buck converter integrates the rectangular current waveform drawn by the switch into a triangular waveform which the impedance of the supply wiring converts into what is called the reflected ripple voltage.
> 
> Thus the inductance and resistance of the battery loop wiring affects the level of observed ripple voltage. If the impedance of this loop is too high then the controller won't operate correctly, but that would be true _regardless of the amount of capacitance present!
> _


The principal of a BuckConveter is to Reduce the Source voltage to the load voltage.
The "Input" capacitance is part of the Source and has no effect in the Buck process.
The integration is from the Reactance(inductance) in the Circuit.
In a pure buck circuit there is a Source, Switch, Diode, Inductance and load. The Diode is Across the Inductance and load. See the diagram at the bottom.
here is a one discussion about Buck Circuits.
http://en.wikipedia.org/wiki/Buck_converter
As a note the actual inductance of wires where the flux is not crossing another part of the wires is unity, so unless feed cables are coiled they have effectively no Inductance in the scheme of things.
Also note that the Feed cables have current flow that makes the wire resistance a factor, that the Resistance of circuit is increased.
in the practical world, there is parasitic capacitance, so the circuit is not pure inductance but a Reactance of the Inductor and parasitic capacitance.
The Inductor in this case is the field and armature of the motor.
and the motor is the load measured in Impedance (reactance and the resistance of the wire).
as a note if the if the feed cables have a current where the resistance it will effect the Impeadance Then the effect of the Buck is reduced.


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## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> The input capacitor of the buck converter integrates the rectangular current waveform drawn by the switch into a triangular waveform which the impedance of the supply wiring converts into what is called the reflected ripple voltage.
> 
> Thus the inductance and resistance of the battery loop wiring affects the level of observed ripple voltage. If the impedance of this loop is too high then the controller won't operate correctly, but that would be true _regardless of the amount of capacitance present!_


I was actually wondering more about the other direction. I've got about 18 inches of cable from the most negative to the controller and 36 inches from the most positive to the controller (a Soliton would just about reverse those cable lengths.) From those some most positive and most negative cells I have about 12 inches and 24 inches of 10 gauge to terminal strip where the charger and DC to DC converter are connected. Is the DC to DC gonna catch hell by being so close (electrically) to the controller? If I understand correctly, higher frequency switching and more capacitance at the IGBTs (or MOSFETs) the smaller the amplitude of the sawtooth. 

I had an idea about the throttle control in the Soliton. I know they where designed for a 3 wire variable voltage setup. You know some people are installing a pull-up resistor and and running a 2 wire pot box. How about a software option that would cause the controller to cut output if the "throt" went over 4 volts? (catching a broken wire on a 2 wire throttle)


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> ...The "Input" capacitance is part of the Source and has no effect in the Buck process.


Au contraire, mon frere, the input capacitor is critical to the buck converter's operation and survival. The output capacitor can be deleted, however, without ill effect.



bjfreeman said:


> The integration is from the Reactance(inductance) in the Circuit.


The pulses of current delivered to the *load* are integrated by the inductor; the pulses of current drawn from the supply are integrated by the capacitor.



bjfreeman said:


> ...As a note the actual inductance of wires where the flux is not crossing another part of the wires is unity, so unless feed cables are coiled they have effectively no Inductance in the scheme of things.


Nope. Any conductor will exhibit inductance unless the flux created from the flow of current therein is 100% cancelled out by an opposing flux. Said cancellation is typically performed by placing the forward and return conductors as close to each other as possible without actually touching, but absent that sort of arrangement, a wire of any diameter in free space - and not coiled up, either - will exhibit approximately 20nH/inch of inductance.


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> ...Is the DC to DC gonna catch hell by being so close (electrically) to the controller? If I understand correctly, higher frequency switching and more capacitance at the IGBTs (or MOSFETs) the smaller the amplitude of the sawtooth.


Ah, okay. Well, if the dc/dc converter was designed for use in an EV - where high reflected ripple is to be expected - then it should work fine. However, every one that I have seen - including the pricy Zivans - exposes its input capacitor directly to the HV input supply. Dumb.

Rebirth Auto sells an inductor that I spec'ed out specifically for protecting chargers and dc/dc converters, but you can do a decent enough job by simply coiling up one of the supply wires to the dc/dc converter about 100x. NB - that will be more practical to do with, say, 16awg wire rather than 10awg 




EVfun said:


> I had an idea about the throttle control in the Soliton. I know they where designed for a 3 wire variable voltage setup. You know some people are installing a pull-up resistor and and running a 2 wire pot box. How about a software option that would cause the controller to cut output if the "throt" went over 4 volts? (catching a broken wire on a 2 wire throttle)


Technically speaking, we don't approve of the use of 2-wire throttles with our controllers, but, yes, we are aware that some people use them and to those people we have said, "it's your life, squander it however you see fit". However, an industrial customer wanted to use a 4-20mA loop to control throttle so we have already implemented the high throttle signal lockout function in the code, just not for a controller model you can buy right now. 

That said, the brake input function - if enabled - will kill the motor output regardless of throttle setting when the brakes are applied, so that accomplishes much the same thing without nuisance tripping of a throttle lockout function because a Hall effect pedal has drifted out of range, etc.


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## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Au contraire, mon frere, the input capacitor is critical to the buck converter's operation and survival. The output capacitor can be deleted, however, without ill effect.


 So you don't agree with the publish design criteria for a buck process.



> The pulses of current delivered to the *load* are integrated by the inductor; the pulses of current drawn from the supply are integrated by the capacitor.


as I said the input capacitor is part of the supply and not part of the Buck process. it is the Diode as a second switch that completes the Buck process.



> Nope. Any conductor will exhibit inductance unless the flux created from the flow of current therein is 100% cancelled out by an opposing flux. Said cancellation is typically performed by placing the forward and return conductors as close to each other as possible without actually touching, but absent that sort of arrangement, a wire of any diameter in free space - and not coiled up, either - will exhibit approximately 20nH/inch of inductance.


What is the Inductance of the motor and what percent is the inductance of the motor is the wire> Hence it is negligible as I stated.


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## somanywelps (Jan 25, 2012)

Was I correct in interpreting an earlier statement that the soliton 1 was capable of regeneration, but it did not have it enabled in software? (For reference, I'm aware that regen with series DC (energized and with interpoles) is optimistically 30%, but the reduction on brake pad/rotor/caliper wear cannot be underestimated.)


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## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Technically speaking, we don't approve of the use of 2-wire throttles with our controllers, but, yes, we are aware that some people use them and to those people we have said, "it's your life, squander it however you see fit". However, an industrial customer wanted to use a 4-20mA loop to control throttle so we have already implemented the high throttle signal lockout function in the code, just not for a controller model you can buy right now.
> 
> That said, the brake input function - if enabled - will kill the motor output regardless of throttle setting when the brakes are applied, so that accomplishes much the same thing without nuisance tripping of a throttle lockout function because a Hall effect pedal has drifted out of range, etc.


But doesn't a 3 wire potentiometer throttle suffer the same wide open throttle risk as a 2 wire with pull-up resistor? I would think that if the ground wire (to SGND) where broken or got disconnected there would be 5 volts on the "throt" input (if it is a high impedance signal connection.) 

The brake inhibit is a good point for any installation. Plus, from the description in the Soliton manual it sounds like a handy hill holder function too (just don't floor the throttle before releasing the brake.) I would even suggest that if someone is using the Curtis pot box they may want to connect the microswitch so that just releasing the throttle sends a brake signal to the Soliton. (COM to the brake inhibit, NC to the brake lights, and NO to power would be my suggestion) Getting off the throttle happens even before getting on the brakes.


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## somanywelps (Jan 25, 2012)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> But doesn't a 3 wire potentiometer throttle suffer the same wide open throttle risk as a 2 wire with pull-up resistor? I would think that if the ground wire (to SGND) where broken or got disconnected there would be 5 volts on the "throt" input (if it is a high impedance signal connection.)
> 
> The brake inhibit is a good point for any installation. Plus, from the description in the Soliton manual it sounds like a handy hill holder function too (just don't floor the throttle before releasing the brake.) I would even suggest that if someone is using the Curtis pot box they may want to connect the microswitch so that just releasing the throttle sends a brake signal to the Soliton. (COM to the brake inhibit, NC to the brake lights, and NO to power would be my suggestion) Getting off the throttle happens even before getting on the brakes.


They should be able to detect off-scale high because the actual range of the potentiometer is much much more than the amount when it is used as a throttle.


----------



## DJBecker (Nov 3, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> But doesn't a 3 wire potentiometer throttle suffer the same wide open throttle risk as a 2 wire with pull-up resistor? I would think that if the ground wire (to SGND) where broken or got disconnected there would be 5 volts on the "throt" input (if it is a high impedance signal connection.)


Unlike a volume control style variable resistor, an automotive TPS doesn't have the wiper cover the whole track over the 90 degree rotation. The effect is that the output voltage doesn't quite cover the full range, and it's easy to detect a supply wire break or a short in the control wire. For Bosch the output is 4% to 96%, with some variation for the dual slope TPS (the low speed output goes to full output in 22.5 degrees). The TPS we are currently using starts at about 5% (223/4096) as installed, so it's very close to the datasheet.

One way to detect a break in the control wire is to use a high value pull-up or pull-down resistor. It takes only a few microamps to detect a completely broken connection. Bosch specs a maximum of about 20uA of wiper current, so it's a *really* weak pull-down.


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> So you don't agree with the publish design criteria for a buck process.


 You start to argue buck converter designs with the guy that has designed the hardware for the most bad-ass racing controller ever seen (so far)?

Ehe. Eheheh. Hehehehehehehehe! This is gonna be fun.

*Makes popcorn enough for the whole audience*



somanywelps said:


> Was I correct in interpreting an earlier statement that the soliton 1 was capable of regeneration, but it did not have it enabled in software? (For reference, I'm aware that regen with series DC (energized and with interpoles) is optimistically 30%, but the reduction on brake pad/rotor/caliper wear cannot be underestimated.)


Yes. We've even tried it out but the initial tries weren't really promising.

From a technical point of view it's a bit cumbersome to get it to work, both for the end user since it demands contactors that can shift one of the fields to turn the motor into a generator but also for the controller software since the series wound generator is a bit tricky to tame. We didn't saw those problems that apparently other had, that the current rushed out of control and blew the silicon, but if I remember correctly it was hard to get regeneration running in a predictable manner.

I'm not sure if series wound regeneration is especially inefficient though. SepEx-motors regen successfully and all I've heard is that they're pretty good at it too. However, you do have losses (twice) in the transmission, the motor, the controller and the batteries and it means that all regenerating systems will be pretty inefficient. I doubt that you'll get even close to 30% no matter technology.

And, well, you can buy several brake pads for the cost of a contactor so I don't think it's worth the trouble. Especially not if the equation calls for my and Tess work to be done volunteerly. 



EVfun said:


> But doesn't a 3 wire potentiometer throttle suffer the same wide open throttle risk as a 2 wire with pull-up resistor? I would think that if the ground wire (to SGND) where broken or got disconnected there would be 5 volts on the "throt" input (if it is a high impedance signal connection.)


Ah, yes, but for a two wire pot either wire can break and cause a runaway where a three wire will only run high if GND breaks. Otherwise it will just be detected as off.

Also, the most common problem (especially with cheap potentiometers) isn't the wires breaking but the whisker giving in and in that case a controller with a three wire pot will just detect zero throttle input.



somanywelps said:


> They should be able to detect off-scale high because the actual range of the potentiometer is much much more than the amount when it is used as a throttle.


Well, that depends on the assembly. I don't think I've seen any throttle pot assembly that uses the full 5 Volt range but there are hall effect assemblies that does and those would then trig a fault if you floor it. That would, I think, be slightly annoying...


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> So you don't agree with the publish design criteria for a buck process.


No, I just don't agree with you.



bjfreeman said:


> as I said the input capacitor is part of the supply and not part of the Buck process. it is the Diode as a second switch that completes the Buck process.


Correct - from a *theoretical* standpoint you only need a controlled switch, a freewheeling diode and an inductor to make a buck converter. 

I suggest you try building a buck (or buck-boost) converter and tell me what you see when you scope the waveform at the collector (drain) of the switch. Now remove the input capacitor and note the difference. Don't forget to wear your safety glasses when you do this as the switch will eventually fail catastrophically from repeatedly avalanching.



bjfreeman said:


> What is the Inductance of the motor and what percent is the inductance of the motor is the wire> Hence it is negligible as I stated.


Sure the inductance of the source wiring should be much less than the inductance of the motor, but it is still inductance and it still stores energy according to the equation 0.5LI². Unless that energy has somewhere to go when the switch turns *off* it will avalanche the switch, typically destroying it within 10 cycles or less.


----------



## Tesseract (Sep 27, 2008)

somanywelps said:


> Was I correct in interpreting an earlier statement that the soliton 1 was capable of regeneration, but it did not have it enabled in software? (For reference, I'm aware that regen with series DC (energized and with interpoles) is optimistically 30%, but the reduction on brake pad/rotor/caliper wear cannot be underestimated.)


In over 3 years here I have learned not to argue with someone when they think regeneration is valuable, but I will say that a 5% boost in range is more realistic and that I went 60k miles before I replaced the brake pads on my last vehicle, so any claims of extreme savings from regeneration strike me as hopelessly optimistic. 

At any rate, to turn a series DC motor into a generator you need to reverse* the field polarity w/r/t the armature's rotation, then flip the motor controller from buck to boost mode. The Soliton1 hardware has the ability to flip from buck to boost, and we have succeeded in getting a WarP-9 to regenerate with it "under laboratory conditions", but to implement this function in a general release of the code would require lots of tweaking to make it safe. I mean, we don't like to see contactors in the motor circuit at all, but a set of reversing contactors that are under the control of the Soliton1? That would require an insane level of paranoia in the code to protect against their unintended activation. That's a whole lot of work for what would appear to be very little tangible reward (though, we realize, plenty of "intangible" reward).

One day we probably will go to all the trouble to add regen to the Soliton1, just for the bragging rights, but that ain't gonna happen until everything else on the development docket gets done first.


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> But doesn't a 3 wire potentiometer throttle suffer the same wide open throttle risk as a 2 wire with pull-up resistor? I would think that if the ground wire (to SGND) where broken or got disconnected there would be 5 volts on the "throt" input (if it is a high impedance signal connection.)


Yes, should the connection to SGND be broken a 3 wire pot will fail in exactly the same bad way as a 2 wire rheostat. The difference is that with a 2 wire rheostat ALL failures result in a wide open throttle signal, whereas with a 3-wire pot, only 1 failure results in that particular situation, while all others result in the throttle signal going to zero. So it is matter of degrees, here.




somanywelps said:


> They should be able to detect off-scale high because the actual range of the potentiometer is much much more than the amount when it is used as a throttle.


Correct - our throttle, for example, typically calibrates out to a range of somewhere around 15% to 75%, so it would be easy to detect an out-of-bounds condition and inhibit motor output as a result.

However, in the real world of experience we have found that so many throttles drift so much - especially the Kelly Hall-effect pedals - that this function causes numerous nuisance trips. The fact of the matter is that using a good throttle transducer and being careful with your wiring - it's your life that is at stake, after all - reduces the probability of a broken ground connection to near zero.

And, as I've mentioned before, there is always the brake input which overrides throttle on the Soliton controllers.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> You start to argue buck converter designs with the guy that has designed the hardware for the most bad-ass racing controller ever seen (so far)?
> 
> Ehe. Eheheh. Hehehehehehehehe! This is gonna be fun.
> 
> *Makes popcorn enough for the whole audience*


I Know many that have built electronics that work but don't know why.
and I am not trying to argue only get the real reason why something works.
if this gets to an argument, I will leave, that is not my intent.


----------



## Jan (Oct 5, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> I Know many that have built electronics that work but don't know why.



Mmmm. I'm one of the odd, few people, that don't know why it doesn't work.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> No, I just don't agree with you.
> Correct - from a *theoretical* standpoint you only need a controlled switch, a freewheeling diode and an inductor to make a buck converter.
> I suggest you try building a buck (or buck-boost) converter and tell me what you see when you scope the waveform at the collector (drain) of the switch. Now remove the input capacitor and note the difference. Don't forget to wear your safety glasses when you do this as the switch will eventually fail catastrophically from repeatedly avalanching.


The Circuit you used showed an inductance between the switch (semiconductor), with no spike protection, and the buck diode. switch is not protected by the Buck Diode, So yes, with that configuration you have an improperly designed Buck Circuit and yes the Semiconductor switch will blow up. An putting a capacitor in will reduce the reverse EMF effect but is not the proper way to design a buck circuit.
However in a correctly designed Buck where all the inductance is after the diode and the proper diode is specified that would not be necessary. All Reverse EMF caused by the inductance would be shorted by the Buck diode.
I started building both Buck and Boost circuits in 85 and have many circuits under my belt. So I have a lot of experience.


> Sure the inductance of the source wiring should be much less than the inductance of the motor, but it is still inductance and it still stores energy according to the equation 0.5LI². Unless that energy has somewhere to go when the switch turns *off* it will avalanche the switch, typically destroying it within 10 cycles or less.


you are now talking about protecting the switch from spikes, but has nothing do to with a Buck circuit.
And yes good design says you should have a diode across the switch to take care of any incidental spikes that may occur. The diode should be as close to the switch as possible physically. Therefore using a proper mosfet or IGBT that has the diode internally is best. But that diode is not part of the Buck circuit or process.


----------



## DJBecker (Nov 3, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> ... but is not the proper way to design a buck circuit.
> However in a correctly designed Buck where all the inductance is after the diode and the proper diode is specified that would not be necessary.


Those are unavoidable parasitic circuit elements.

If you have actually designed buck circuits, don't you model them? Including the important non-discrete elements?



bjfreeman said:


> And yes good design says you should have a diode across the switch to take care of any incidental spikes that may occur.


Where would that diode go?


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



DJBecker said:


> Those are unavoidable parasitic circuit elements.
> 
> If you have actually designed buck circuits, don't you model them? Including the important non-discrete elements?


I gave a link to the full discussion and was trying to keep this discussion as simple as possible.
and yes just like you design a circuit board and put a lot of capacitors on it to reduce the interference.
I was addressing the circuit that was shown on how his system worked. with out full schematics and layout I can not be more practical
However the principals of the Buck circuit if not followed will cause grief. Like using a capacitor that will dry out and fail compared to a properly installed Buck Diode.



> Where would that diode go?


answer in he next sentence. please re-read.


----------



## DJBecker (Nov 3, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> answer in he next sentence. please re-read.


The freewheel diode doesn't protect the drive device from source inductance. It provides a current flow path for load inductance.

The capacitors (or a snubber circuit) are there to protect the drive device from the voltage spike caused by source inductance. Or a really slow heat-generating turn-off.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



DJBecker said:


> The freewheel diode doesn't protect the drive device from source inductance. It provides a current flow path for load inductance.
> 
> The capacitors (or a snubber circuit) are there to protect the drive device from the voltage spike caused by source inductance. Or a really slow heat-generating turn-off.


As source are you defining the Supply or the Motor Reverse EMF created by the Motor inductance.
The diode of the switching device (drive device) should not see an Motor reverse EMF if the Buck Diode is connected so it shorts all the Reverse EMF to nothing above 0.7 volts.
so the Diode accross the switch (drive device) deal with spike generated by other components outside the Buck circuit.
As I said before the Proper Buck Diode is necessary to keep the slow heating of the Switch (drive device). Proper Buck diode is a ultra fast with sufficient Power handling, that all the heat is disparate.
The difference between Capacitive Snubber and the Buck diode or the free wheeling Diode is the Capacitor stores the energy then bleeds off the current, where the Diodes dissipate the energy as heat.
As long as the circuit used in not defined as a Buck circuit then all of this is mute.


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> An putting a capacitor in will reduce the reverse EMF effect but is not the proper way to design a buck circuit.
> However in a correctly designed Buck where all the inductance is after the diode and the proper diode is specified that would not be necessary.


So let me get this straight... you are saying that the input capacitor wouldn't be necessary if only one were to somehow move all of the inductance in the circuit past the freewheeling diode?

Well, you would also have to remove all of the resistance from the source side of the switch, but I suppose that could be done by using superconductors for the wiring. And I guess you could get the inductance of the source wiring down low enough that a capacitor wouldn't be needed if you built the buck converter *inside* each cell of a traction battery...

In other words, bjfreeman, your argument is totally divorced from reality. Please find some other thread to troll.


----------



## JRP3 (Mar 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> .........


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

(


Tesseract said:


> So let me get this straight... you are saying that the input capacitor wouldn't be necessary if only one were to somehow move all of the inductance in the circuit past the freewheeling diode?


Nor sure how you got that idea. though a Buck Diode can be a freewheeling Diode, it function is not how you visualize.
I said that the input capacitor(on the DC side of the switch) is not part of the Buck Circuit Design, not that is required for the Supply (DC supply) Filtering.
so of course you getting the misconception.
Please start with my first post and work down.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Please start with my first post and work down.












The post where you showed this circuit?



bjfreeman said:


> ... though a Buck Diode can be a freewheeling Diode, it function is not how you visualize.


Let me count the diodes in the circuit. One...... It is the Free Wheeling Diode. What confuses you bj? Why do you start talking about "Buck Diode"? What's that? A $1.00 diode 



bjfreeman said:


> Nor sure how you got that idea.......so of course you getting the misconception.





bjfreeman said:


> and I am not trying to argue only get the real reason why something works.


It sure doesn't seem like you mean this. Several weeks ago you argued there was no current multiplication and we should put the FWD in the motor junction box. You read wikipedia and come back here to lecture Tesseract on motor controller (buck converter) design theory


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> You read wikipedia and come back here to lecture Tesseract on motor controller (buck converter) design theory


Well, I at least finds it highly entertaining.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> The post where you showed this circuit?


Yes and the Diode function is to short, like a switch the reverse EMF so the max voltage is 0.7 volts.
Others started bringing other diodes into the conversation. I call this a Buck Diode to differentiate from other diodes, since it has a specific purpose in a Buck process, that no other diode has.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Others started bringing other diodes into the conversation.


All I have or anyone else involved here have been concerned with is the FWD (Free Wheeling Diode). You have been the only one confused and talking about "other" diodes. Again, there is ONE diode in the circuit. It is the Free Wheeling Diode.


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Tesseract said:
> 
> 
> > So let me get this straight... you are saying that the input capacitor wouldn't be necessary if only one were to somehow move all of the inductance in the circuit past the freewheeling diode?
> ...


You aren't sure where I got that idea? Does this ring a bell?



bjfreeman said:


> ...However in a correctly designed Buck where all the inductance is after the diode and the proper diode is specified that would not be necessary. All Reverse EMF caused by the inductance would be shorted by the Buck diode....


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> You aren't sure where I got that idea? Does this ring a bell?





> Originally Posted by *bjfreeman*
> _...However in a correctly designed Buck where all the inductance is after the diode and the proper diode is specified that would not be necessary. All Reverse EMF caused by the inductance would be shorted by the Buck diode...._


 As major states there is one diode in a buck circuit. and based on that there is no capacitor between the Switch and Buck diode (diode) necessary if the Buck Diode is doing it job of keeping the Reverse EMF to 0.7 volts.
Now the link goes into parasitic but I did not want to cloud the issue since it seems the basic Buck concept is hard to understand by those here.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> ......there is one diode in a buck circuit. and based on that there is no capacitor between the Switch and Buck diode ...


Of course not. Nobody ever said to put a capacitor there.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> Of course not. Nobody ever said to put a capacitor there.


go back to responses to my first post and there was talk about capacitors, while i was addressing the circuit I put up.
I could only surmize, since they were discussing capacitors, they were putting them in buck circuit.
if you look at my responses I did my best to clarify.
even 

Originally Posted by *Tesseract*  
_So let me get this straight... you are saying that the input capacitor wouldn't be necessary if only one were to somehow move all of the inductance in the circuit past the freewheeling diode?_


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> go back to responses to my first post and there was talk about capacitors, while i was addressing the circuit I put up.
> I could only surmize, since they were discussing capacitors, they were putting them in buck circuit.
> if you look at my responses I did my best to clarify.
> even
> ...


What don't you understand about input capacitor?


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> What don't you understand about input capacitor?


I understand it is not part of the Bucking circuit and process. for this discussion to keep it on track that is all I am focused on.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> for this discussion to keep it on track that is all I am focused on.


I am not sure what you think you're discussing. This thread is about


> Controller discussion


 and more specifically, DC motor controllers, which are called buck converters.



bjfreeman said:


> major said:
> 
> 
> > What don't you understand about input capacitor?
> ...


You have shown over and over again that you make up your own definitions. So I have no idea what you actually mean by "Buck Diode" or "Bucking circuit and process". But the DC motor controller (generally accepted as called a buck converter) always uses input capacitors, every one of them.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> I am not sure what you think you're discussing. This thread is about and more specifically, DC motor controllers, which are called buck converters.
> 
> 
> 
> You have shown over and over again that you make up your own definitions. So I have no idea what you actually mean by "Buck Diode" or "Bucking circuit and process". But the DC motor controller (generally accepted as called a buck converter) always uses input capacitors, every one of them.


I see that the buck Circuit and process has been defined by many, just do a Google or read an Engineering Book. it is this group that redefines it, which is why it seem they can't comprehend as you.
There for the discussion are so much smoke being blown up peoples butt.
Now if you want to call something fancy why not call it a switched integration controller


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> I understand it is not part of the Bucking circuit and process....


Oh, you want to be "topologically pure", do you? Well then, as long as the load is purely resistive you don't need the "Buck diode", either, which means a buck converter topologically reduces to... a single switch. With this kind of definition even the thermostat in a toaster oven can be called a buck converter...



bjfreeman said:


> I see that the buck Circuit and process has been defined by many, just do a Google or read an Engineering Book. it is this group that redefines it, which is why it seem they can't comprehend as you....


No, bjfreeman, you are the one who is trying to "buck" the laws of physics here, so it is up to you to find evidence to support your position.


----------



## Jan (Oct 5, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

I think I understand Freeman's method. Just asking questions about how electronics or circuitery works, hardly ever is responded with an explanation. The best you can expect is a link. Claiming you've got a homebrew nuclear powerplant in your back yard, and/or claiming several impressive degrees in several impressive studies generates a lot more attention.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> I see that the buck Circuit and process has been defined by many, just do a Google or read an Engineering Book. it is this group that redefines it, which is why it seem they can't comprehend as you.
> There for the discussion are so much smoke being blown up peoples butt.
> Now if you want to call something fancy why not call it a switched integration controller


The subject here is PWM DC motor controllers. They are commonly called buck converters. Is it 100.0000% correct to call the PWM DC motor controller a buck converter? Who cares? If you don't like it, suck it up and get on with it.

I don't know what confuses you about the PWM DC motor controller. It uses a Free Wheeling Diode enabling current multiplication. The controller package needs input capacitors and all PWM DC motor controllers devote about one third of the package volume to input capacitors. The designers and manufacturers of DC motor controllers don't do this to blow smoke up your butt. They do it to make the DC motor controller function properly. 

Can you comprehend that?

major


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> The subject here is PWM DC motor controllers. They are commonly called buck converters.


if they have a valid Buck circiut in them, then yes.


> I don't know what confuses you about the PWM DC motor controller. It uses a Free Wheeling Diode enabling current multiplication.


So tell me how a Free Wheeling Diode enables current multiplication. This is a new science I am not aware of.


> The controller package needs input capacitors and all PWM DC motor controllers devote about one third of the package volume to input capacitors.


I said the input capacitor is part of the supply. so how are we different. the Function of them is to respond faster than the batteries can, when the throttle is pushed down. Still they don't have any effect on the Buck circuit process.
in PWM DC circuits, the longer the pulse or more rapid pulses the higher the voltage integrated by the motor inductance.
however the Input capacitors are before the PWM circuits so their consideration has to do the Supply side fo the PWM.
The buck Circuit, if it exist, is part of the PWM circuit.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> So tell me how a Free Wheeling Diode enables current multiplication. This is a new science I am not aware of.


We explained that to you several times in this thread: http://www.diyelectriccar.com/forums/showthread.php/max-size-wire-motor-68439p13.html 



bjfreeman said:


> however the Input capacitors are before the PWM circuits so their consideration has to do the Supply side fo the PWM.


Yet the input capacitors are always assembled in the motor controller and thus considered part of the "motor controller" which is the subject of this thread.


----------



## DIYguy (Sep 18, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> Well, I at least finds it highly entertaining.


Darn! Miss a few days and u miss a lot.  

Us electronically challenged (me, not u) need guys like BJ so we can learn from the guys who know what they are talking about. Don't piss him off too much.... please!
For me, a "buck" has (hopefully) about 10 points and waves a white flag at u (if u missed him, that is). If anyone wants to argue about a gut hook or antler rattling I'm "game".


----------



## bjfreeman (Dec 7, 2011)

the discussion about cable causing spikes, here is a real world test.
take, say 2 25 foot cables and a load Like a big Electric heater.
connect knife switch, that is connected to the battery pack, and connect it to the load and using a trigger scope with freeze, then close and open the knife to get the spike the load will cause.
then connect the cables so they are far apart(no flux interaction) and repeat.
the difference between the two readings will tell you the spike you can expect from the cables.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> We explained that to you several times in this thread: http://www.diyelectriccar.com/forums/showthread.php/max-size-wire-motor-68439p13.html


you show a model of a circuit that part of the inductance was shorted by the diode(what I call a buck diode) so to keep the Reverse EMF to 0.7 volts and not punch the switch. the Problem with model was you had inductance between the Switch and the Diode, so the Reverse emf from that inductance would present at the switch.
however I don't see any explanation on how the diode multiplies current.


> Yet the input capacitors are always assembled in the motor controller and thus considered part of the "motor controller" which is the subject of this thread.


Yes and the "motor controller" has circuits in that make it work a certian way. Understanding those better helps understand the characteristic of the "motor controller"*

Not all *"motor controller" are created the same. that is like saying a discussion about cars they are all the same.

Note: I did not chime in on this thread till someone stated some facts were not acurate about the workings of a "motor controller".


----------



## palmer_md (Jul 22, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Note: I did not chime in on this thread till someone stated some facts were not acurate about the workings of a "motor controller".


The problem is that you are arguing motor controller design with the folks who have actually designed and built (arguably) the best DC motor controller on the retail market.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> the Problem with model was you had inductance between the Switch and the Diode,


Show me this.


----------



## esoneson (Sep 1, 2008)

*You a funny man, bjfreeman, you make me laugh.*

I make popcorn and drink root beer and read you posts.
You a funny man, bjfreeman.
You make me laugh. 

You clever man to twist these things so.

No sense non-sense is you theme.
Jersey girls want you be on their show.
Comedian like you make good money.

You a funny man, bjfreeman. 

Eric


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> however I don't see any explanation on how the diode multiplies current.


What I said was: 


major said:


> It uses a Free Wheeling Diode enabling current multiplication.


If you have a transformer with a 2 to 1 turns ratio, the secondary current is twice the magnitude of the primary current, isn't it? This can be called current multiplication. It isn't getting anything for free. The secondary voltage is half of the primary, so equal power in and power out (neglecting a small loss for example purpose). The transformer uses the magnetic field to accomplish this.

The motor controller (which we call a buck converter) does much the same thing by using the magnetic field in the motor. Whereas the transformer relies on AC to get the needed change in magnetic field, the motor controller uses PWM to create a changing current and therefore a changing magnetic field. 

There must be a node and alternate path for the load current and the Free Wheeling Diode provides this. The load current (motor current) is the sum of the switch current (battery current) and the FWD current. The motor voltage is the average voltage or the battery voltage times the PWM %. Again, like the transformer, power into the motor controller is equal to the power out (neglecting loss). So at 50% PWM, the motor voltage is half the battery voltage and the motor current is twice the battery current.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> Show me this.


Post the diagram you used.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> the Problem with model was you had inductance between the Switch and the Diode,





major said:


> Show me this.





bjfreeman said:


> Post the diagram you used.


You say there is a problem with something I did. I say show me. And you tell me to post something????? What are you talking about? What diagram? What model? What inductance? Are you sure it was me?


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Post the diagram you used.


I reposted this one which you lifted from wikipedia:


major said:


>


In the referenced thread I used this one from frodus:


frodus said:


>


Does that help?


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> The motor controller (which we call a buck converter) does much the same thing by using the magnetic field in the motor. Whereas the transformer relies on AC to get the needed change in magnetic field, the motor controller uses PWM to create a changing current and therefore a changing magnetic field.


I agree.



> There must be a node and alternate path for the load current and the Free Wheeling Diode provides this.


There must be Reactance in this Case Inductance that store the Current provided by the switch in a magnetic field (flux). During this cycle the Diode, Across the Inductor and switch has no effect they are reverse Biased.
When the switch is turned off, the field collapses, causing the energy stored (flux) in the Inductance to collapse. The flux cuts across many winding causing the Inductance to be a source called Reverse EMF. the amount of voltage is a function of Q. This the same amount of energy as was provide by the switch but created in a shorter time.
This does not require a Diode, across the inductor, to do.
The function of the Diode, accross the Inductor, during the collapse of the Field and the Resulting EMF is to provide a complete path back to the inductance keeping the EMF at 0.7 volts. the path is from one side of the inductance to the other.
Now if the switch is turned on before the completion of the collapse, as is done in these switching circuits, the Field stops collapsing and starts building thus the Reverse Emf is halted and the current in diode, across the inductor, ceases.

Now if diode was not across the Inductance, the total emf as much as 1000 times the input voltage (based on the Q) will be at the Switch. if no FWD is across the switch, end up blowing the semiconductor switch. if the FWD is in the Switch, then the Switch will require additional heat sinking , as compare to if an additional diode was across the inductance. If the FWD is outside the switch then it will become warm and need addition cooling, compared to if an additional Diode was across the inductance.

The use of the Diode across the inductance was first used with mechanical switches and Relays to reduce the spark when the switch/relay was opened. 

The Buck comes from the fact that the series inductor bucking the current flow, from the Flux cutting other wires as the flux increases.
The Buck Diode (then one across the Inductor) function is to limit Reverse EMF.
Note: like using parallel devices for the switch you may need parallel Diodes across the inductor, depending on how much wattage is being passed through it.
Hope I cleared up misinformation.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> I reposted this one which you lifted from wikipedia:
> 
> In the referenced thread I used this one from frodus:
> 
> Does that help?


that is correct way but not the diagram you presented before.
the diagram before you showed the diode between the inductor and the motor.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> There must be Reactance in this Case Inductance that store the Current provided by the switch in a magnetic field (flux). During this cycle the Diode, Across the Inductor and switch has no effect it is reverse Biased.
> When the switch is turned off, the field collapses, causing the energy stored (flux) in the Inductance to collapse. The flux cuts across many winding causing the Inductance to be a source called Reverse EMF. the amount of voltage is a function of Q. This the same amount of energy as was provide by the switch but created in a shorter time.
> This does not require a Diode, across the inductor, to do.
> The function of the Diode, accross the Inductor, during the collapse of the Field and the Resulting EMF is to provide a complete path back to the inductance keeping the EMF at 0.7 volts. the path is from one side of the inductance to the other.
> ...


Your quotes in color. My comments in black.

During this cycle the Diode, Across the Inductor and switch......The Free Wheeling Diode is never across the Inductor and switch.

Diode, accross the Inductor.......The Free Wheeling Diode is never just across only the inductor. It is across the inductor and load.

if no FWD is across the switch......The Free Wheeling Diode is never across the switch.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> that is correct way but not the diagram you presented before.
> the diagram before you showed the diode between the inductor and the motor.


It was not. These are the only diagrams I recall posting on the subject. The record is intact. Find it and show me. If you can't copy the diagram, simply give me the post# and thread. I have altered or edited nothing in this regard. Show me.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> Your quotes in color. My comments in black.
> 
> During this cycle the Diode, Across the Inductor and switch......The Free Wheeling Diode is never across the Inductor and switch.


did not say that, there is one for each.


> Diode, accross the Inductor.......The Free Wheeling Diode is never just across only the inductor. It is across the inductor and load.


in the case of a motor the inductance and load(resistive component) are the same physical component, however that was not how your origanl model was drawn . The model show the inductance seperate to indicated the circuit is inductive.


> if no FWD is across the switch......The Free Wheeling Diode is never across the switch.


 Some are some are not. which is why I covered both conditions.
do a google on
mosfet with diode protection
and 
IGBT with diode protection


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> did not say that, there is one for each.
> in the case of a motor the inductance and load(resistive component) are the same physical component, however that was not how your origanl model was drawn . The model show the inductance seperate to indicated the circuit is inductive.
> Some are some are not. which is why I covered both conditions.
> do a google on
> ...


Look at the diagram. There is ONE diode. It is the Free Wheeling Diode. That is the motor controller (buck converter).

Again you refer to some fictional "original model" of mine. SHOW ME.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> Look at the diagram. There is ONE diode. It is the Free Wheeling Diode. That is the motor controller (buck converter).
> 
> Again you refer to some fictional "original model" of mine. SHOW ME.


LOL.
I gave a valid description I am not sure why you want to start over.
You seem to have a bent on wanting to prove me wrong.
Have at it. I am willing to let those that want to research what I said find out the facts.


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Some are some are not. which is why I covered both conditions.
> do a google on
> mosfet with diode protection
> and
> IGBT with diode protection


You mean like this one?










EDIT: The one to the right, I mean. Obviously...


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> I gave a valid description....


Of what I am not sure, but it was not relevant to how the motor controller functions.



bjfreeman said:


> I am not sure why you want to start over.


I don't want to start over. What I want is for you to follow through. You blame me for an inaccurate model but cannot produce evidence of its existence. You are wrong but unwilling to even consider that fact.



bjfreeman said:


> You seem to have a bent on wanting to prove me wrong.


You come on here and preach BS. I challenge your nonsense. You ask me for an explanation. I provide it. 

Millions of DC motors use controllers (buck converters) which function in the same way, as I described. References and test data have been supplied in the previous thread by me and other members. 

It is past the point of proving you wrong.


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> ...
> do a google on
> mosfet with diode protection
> and
> IGBT with diode protection


The anti-parallel diode across the switch does not conduct in a buck converter, so whether the switch has one or not is _moot_ and you bringing it up in the first place is _irrelevant_.

You know,when the whole world says you are wrong, sometimes it really means you are wrong, bjfreeman. That you don't get this either means you are incredibly dim-witted and/or a troll.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> =
> You know,when the whole world says you are wrong, sometimes it really means you are wrong, bjfreeman. That you don't get this either means you are incredibly dim-witted and/or a troll.


Actually it is just a few. the rest pay me a lot to do it for them.
Strangely the few are on this forum.
It is egotistical to think this forum is the whole world.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Actually it is just a few. the rest pay me a lot to do it for them.
> Strangely the few are on this forum.
> It is egotistical to think this forum is the whole world.


There have been approximately 11,000 views of the three threads concerning this subject on which you have argued your position. Not one post has been seen in your support.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> There have been approximately 11,000 views of the three threads concerning this subject on which you have argued your position. Not one post has been seen in your support.


or those that know they don't know, so are wise enough not to comment, but interested enough to learn.


----------



## esoneson (Sep 1, 2008)

ROFLOL!!!!!!

You a funny man, BJfreeman, you a funny man.
You make me laugh.
Sarcasm you style now.
Change all time.
Funny.....keep me laughing. 

Eric


----------



## bjfreeman (Dec 7, 2011)

esoneson said:


> ROFLOL!!!!!!
> 
> Sarcasm you style now.
> Eric


I saw it more as philosophical statement


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> You mean like this one?
> 
> 
> 
> ...


yes like the one on the right. however as pointed out this is not necessary if the Diode across the motor can maintain the 0.7 volts during the reverse emf cycle. and the diode across the motor is also close to the switch.


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> however as pointed out this is not necessary if the Diode across the motor can maintain the 0.7 volts during the reverse emf cycle. and the diode across the motor is also close to the switch.


...ehm. Wut?

Ok. You're, as we say in Sweden, definitely out biking around now (meaning: totally lost if that wasn't obvious) because the thing is that the diode over the switch doesn't have any function what so ever in a DC-controller. It's not even in the right place. Compare:










with:










Note how the diode ISN'T over the switch in the schematics....?

If the switch were a transistor with a diode it would be aligned with the collector towards the power supply and the emitter towards the coil, meaning that the only time the diode would activate would be if the load generated a voltage higher than pack voltage. That would create a current flowing from the load into the power supply and if the power supply is a battery pack that would mean the batteries would be charged.

Like, oh, I don't know. Regen perhaps...?


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> ...ehm. Wut?
> 
> Ok. You're, as we say in Sweden, definitely out biking around now (meaning: totally lost if that wasn't obvious) because the thing is that the diode over the switch doesn't have any function what so ever in a DC-controller. It's not even in the right place. Compare:
> 
> ...


you have some how missed what I said.
Now the Diode as in the 2nd diagram is there to reduce the reverse EMF to 0.7 volts. if that diode does it job and is located near the switch as I said the diode across the switch not necessary. Infact it will not be effect because the voltage at the switch will be 0.7. Go back and read my full description.
however if the Diode in the 2nd diagram is not located by the switch is it best to have the Diode in the first diagram to protect the switch. this is more a practical consideration than an electrical one.
Also note the 2nd diagram is a model not an actual schematic.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> you have some how missed what I said.
> Now the Diode as in the 2nd diagram is there to reduce the reverse EMF to 0.7 volts.{1} if that diode does it job and is located near the switch{2} as I said the diode across the switch not necessary.{3} Infact it will not be effect because the voltage at the switch will be 0.7.{4} Go back and read my full description.
> however if the Diode in the 2nd diagram is not located by the switch is it best to have the Diode in the first diagram to protect the switch. this is more a practical consideration than an electrical one.
> Also note the 2nd diagram is a model not an actual schematic.


Comments associated with the blue number locations {#}

1) The primary purpose of that diode is to serve as the Free Wheeling Diode.

When the FWD is forward biased it has a 0.7 volt drop across it. It never actually reduces any "reverse EMF" to 0.7 volts. 

I am not sure exactly what you mean by "reverse EMF". If you use convention, and you refer to the induced voltage across the inductance, then when the FWD conducts, that voltage is a polarity considered forward, not reverse. And has a magnitude equal to the armature's generated voltage plus the circuit resistance times the current plus 0.7V.

2) Now you say it should be close to the switch. You have changed your opinion about the Free Wheeling Diode over the past few weeks. 


bjfreeman said:


> So in the case of Motors which are inductive reactive, the FWD should be placed in a junction box on the motor.


3) Wasn't that Tesseract who told you that the anti parallel diode wasn't needed?

4) When the FWD conducts, the switch is open and has a voltage across it equal to source voltage plus 0.7 volts. Not "at 0.7".


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> During this cycle the Diode, Across the Inductor and switch has no effect it is reverse Biased.





bjfreeman said:


> major said:
> 
> 
> > During this cycle the Diode, Across the Inductor and switch......The Free Wheeling Diode is never across the Inductor and switch.
> ...


It is a direct quote from you. How can you deny you said it?

And where is this bogus diagram you accuse me of posting?



bjfreeman said:


> the diagram before you showed the diode between the inductor and the motor.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Originally Posted by *bjfreeman*  
_ During this cycle the Diode, Across the Inductor and switch has no effect it is reverse Biased._


major said:


> It is a direct quote from you. How can you deny you said it?


yes a diode across the switch and a diode across the motor. two diodes different places, different functions.

I should have said they are reverse biased. Did not see the Grammar error till just now.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> And where is this bogus diagram you accuse me of posting?


till your man enough to admit what happened this is a closed subject to me.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> Comments associated with the blue number locations {#}
> 
> 1) The primary purpose of that diode is to serve as the Free Wheeling Diode.
> 
> ...


I am not talking about the induced Voltage across the Inductance like when the switch is closed. I am talking about Generated Voltage caused by the collapse of the Flux. Which is Function for Q.
The diode can only conduct from cathode to anode,when the positive is hooked to the cathode and negative to anode, it is forward biased at that time . the voltage is Reverse the normal condition when it is forward Bias, as when the switch is closed. EMF is another way to say Volts. Hence Reverse EMF.
if you test this, you will see that no matter how much voltage you apply across a forward biased diode, it will only have 0.7 volts across it and if you exceed the Current rating it will destroy itself. 



> 2) Now you say it should be close to the switch. You have changed your opinion about the Free Wheeling Diode over the past few weeks.


you took it out of context. I was saying a few week back that I would put the diode across the motor and that due to spurious spike the Diode across the switch was necessary. in this one I said "if" the Diode accross the motor is near the switch the diode across the switch is not necessary. I still hold to what I said I would do. all my IGBT have the diode across them internally. they come that way from the manufacture. I reverse the IGBT to use the Diode in it for the one across the motor. The Diodes are are rated at the same current as the IGBT.


> 4) When the FWD conducts, the switch is open and has a voltage across it equal to source voltage minus 0.7 volts. Not "at 0.7".


Nope at 0.7 volts, as i stated above, and the current path is from one side the motor to the other side. there is not an other current path, at that time, for that diode.


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> ...


I wish you good luck, 'cause I'm bailing out now. Reading this "discussion" feels more and more like reading 99 bottles on the wall written in lolcode.

I have more constructive ways to spend my time. Toodles.

Or as those kids would probably put it these days.

KTHX


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> that is correct way but not the diagram you presented before.
> the diagram before you showed the diode between the inductor and the motor.





major said:


> And where is this bogus diagram you accuse me of posting?





bjfreeman said:


> till your man enough to admit what happened this is a closed subject to me.


So you call me a liar?

There is an accurate, complete record of what I posted on this forum. You or anyone can examine it. Please do. I never posted such a diagram.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> till your man enough to admit what happened this is a closed subject to me.


Do you learn how to call another man a liar with no supporting evidence here?



bjfreeman said:


> This comes from over 3000 hours of facilitating Men Changing Roles Groups.


----------



## TigerNut (Dec 18, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> major said:
> 
> 
> > And where is this bogus diagram you accuse me of posting?
> ...


Now let's look back at post #72 in this "discussion":


bjfreeman said:


> The Circuit you used showed an inductance between the switch (semiconductor), with no spike protection, and the buck diode. switch is not protected by the Buck Diode, So yes, with that configuration you have an improperly designed Buck Circuit and yes the Semiconductor switch will blow up. An putting a capacitor in will reduce the reverse EMF effect but is not the proper way to design a buck circuit.
> However in a correctly designed Buck where all the inductance is after the diode and the proper diode is specified that would not be necessary. All Reverse EMF caused by the inductance would be shorted by the Buck diode.
> I started building both Buck and Boost circuits in 85 and have many circuits under my belt. So I have a lot of experience.
> you are now talking about protecting the switch from spikes, but has nothing do to with a Buck circuit.
> And yes good design says you should have a diode across the switch to take care of any incidental spikes that may occur. The diode should be as close to the switch as possible physically. Therefore using a proper mosfet or IGBT that has the diode internally is best. But that diode is not part of the Buck circuit or process.


You (bjfreeman) were replying to Tesseract, not Major, and this is obvious because Major hadn't even posted one thing in this thread at that point. The circuit was one that Tesseract had described in words, not a picture. So, "what happened" is that YOU f'ed up and attributed the wrong thing, in the wrong context, to the wrong person.



bjfreeman said:


> I Know many that have built electronics that work but don't know why.
> and I am not trying to argue only get the real reason why something works.
> if this gets to an argument, I will leave, that is not my intent.


Following this discussion has been very interesting, and a good review of basic circuit theory. It's also obvious that in your case, your electronics might work, but not for the reasons that you think they do. In some ways that's worse, because it might lead you to think that you know what you're doing. It's easier to learn from an obvious failure than from an apparent success.


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> ...
> Nope at 0.7 volts, as i stated above, and the current path is from one side the motor to the other side. there is not an other current path, at that time, for that diode.


Sorry, no, you are totally wrong. It seems like a minor point - does the freewheeling diode clamp the switching node to one diode drop above ground (ie - +0.7V) or below ground (ie - -0.7V) - but a failure to get this right illustrates a profound misunderstanding of this otherwise extremely simple circuit.

Once current starts flowing in an inductor it does not like to change magnitude but it really does not like to change direction. The polarity and magnitude of the voltage across an inductor can change at will, however, and the inductor will, in fact, change both to whatever values are necessary to maintain a smooth flow of current in the same direction.

In order for a diode to conduct the anode must be more positive than the cathode by the forward voltage drop (ie - Vf) of the diode. To put it another way, the cathode must be negative with respect to the anode by one Vf (where, just to be clear, Vf is commonly described as 0.7V, though it rarely is exactly that in practice).

Combining these two basic principles of electronics together and applying them to the buck converter, it should be apparent that the inductor will take the cathode of the freewheeling diode negative to maintain current flow when the switch turns off. Current decays in the inductor during the period when the switch is off in a linear fashion according to the amount of inductance and the total circuit resistance of the load, inductor, wiring, etc.

And on that note....



bjfreeman said:


> ....
> I am willing to let you believe what you want.
> I am too busy to debate at this level.
> I wish you all well.
> From Now on I am just a lurker for that the interests me.


So... what happened to you just being a lurker?


----------



## frodus (Apr 12, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

BJ, draw a diagram, take a picture, upload it and post it so we can see what the flying fart you're talking about. 

You've failed miserably in producing a burdon of proof (you "telling" us that it's true isn't enough, we want to see your references, books, pages, PDF's, articles, drawings, etc). The entire way through multiple pages you've skirted around providing any of this information when we've asked. When we ask for it again, you tell us you gave it to us before, yet we cannot find any of it. 

From a while back:



bjfreeman said:


> frodus said:
> 
> 
> > a little tidbit about what I'm talking about:





bjfreeman said:


> frodus said:
> 
> 
> > http://homepages.which.net/~paul.hills/SpeedControl/SpeedControllersBody.html
> ...




Well THAT article is exactly what we're trying to explain.... and there seems to be some breakdown of communication.

From that article:












> The inductance of the field windings and the armature windings have been lumped together and called La.
> Q1 is the MOSFET. When Q1 is on, current flows through the field and armature windings, and the motor rotates. When Q1 is turned off , the current through an inductor cannot immediately turn off, and so the inductor voltage drives a diminishing current in the same direction, which will now flow through the armature, and back through D1 as shown by the red arrow in the figure below. If D1 wasn’t in place, a very large voltage would build up across Q1 and blow it up.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



frodus said:


> From that article:
> 
> 
> 
> ...


as the current flows though La the flux increases, bucking the current flow and stores the Current provided as a magnetic field.


> When Q1 is turned off , the current through an inductor cannot immediately turn off, and so the inductor voltage drives a diminishing current in the same direction, which will now flow through the armature, and back through D1 as shown by the red arrow in the figure below.


once no more current flows because the Q1 is turned off, The magnetic field collapses. The flux cuts across adjacent windings Creating a Voltage. Making the La the source of Voltage. Base on Q will determine the Voltage. The energy
stored in the magnetic field is the same energy provided by the source, but the field collapses at a faster rate than the original current, so the current is large but for a shorter time.


> If D1 wasn’t in place, a very large voltage would build up across Q1 and blow it up.


D1 Complete a circuit back to the other side of La that allow the current to flow. The characteristic of the diode, when forward biased, is it only has a 0.7 potential across it.
it is this characteristic that protect Q1.
When Q1 is turned on again before the the fields completely collapses, as is done in contoller, the flux starts to increase, stopping the La from being a source, and D1 is reverse bias so current through D1 stops.


----------



## frodus (Apr 12, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> as the current flows though La the flux increases, bucking the current flow and stores the Current provided as a magnetic field.


YES!!!!!



bjfreeman said:


> once no more current flows because the Q1 is turned off, The magnetic field collapses. The flux cuts across adjacent windings Creating a Voltage. Making the La the source of Voltage. Base on Q will determine the Voltage. The energy
> stored in the magnetic field is the same energy provided by the source, but the field collapses at a faster rate than the original current, so the current is large but for a shorter time.


Yes, Well, almost, Let me slightly correct you:
Once no more current flows *THROUGH Q1,* the magnetic field starts to colapse, but the current in the motor/diode loop still nonzero as long as PWM > 0 and PWM frequency is greater than the decay time of the motor/diode loop.

We have to consider that this circuit is never kept in an equlibrium state until PWM = 0. When PWM > 0, the current never gets a chance to decay to zero before Q1 is switched on during the next PWM pulse.

It's only after there's no signal to Q1 for t > (decay time of motor loop) that current in all devices is zero.




bjfreeman said:


> D1 Complete a circuit back to the other side of La that allow the current to flow. The characteristic of the diode, when forward biased, is it only has a 0.7 potential across it.
> it is this characteristic that protect Q1.
> When Q1 is turned on again before the the fields completely collapses, as is done in contoller, the flux starts to increase, stopping the La from being a source, and D1 is reverse bias so current through D1 stops.


YES!!!!

That's what we're trying to tell you!


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



frodus said:


> That's what we're trying to tell you!


I have explained this the latest is
http://www.diyelectriccar.com/forums/showpost.php?p=285954&postcount=107
so what is the difference between in light of what you agree with.
Btw, this has been my understanding since 85.
the only difference we have not covered is how this effects motor operation.


----------



## frodus (Apr 12, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

"I" agree with the explanation of this website:
_http://homepages.which.net/~paul.hills/SpeedControl/SpeedControllersBody.html_


_I don't think you have been effective at communicating. Your writing is very confusing and full of grammatical mistakes which makes it harder for others to understand what you're trying to communicate._

_You also provide no references for any material, so it's very hard to tell if we're just misunderstanding you, or if you're arguing a different point._

_IF you had provided references, as requested, we'd have seen long ago, that you were basically agreeing with the basic function of a Buck converter._


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



frodus said:


> _You also provide no references for any material, so it's very hard to tell if we're just misunderstanding you, or if you're arguing a different point._
> 
> _IF you had provided references, as requested, we'd have seen long ago, that you were basically agreeing with the basic function of a Buck converter._


Actually I have and it has been phoo phooed.
and by my response to the article you provided, it is not complete, therefore does not provided the information to see how other thought processes that have posted here are erroneous.


----------



## frodus (Apr 12, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

I can't find your book/pdf/article/link/schematic reference in any post I can find. 

You have a difficult time with effective communication of your ideas and have issues with writing correct english (bad grammar, spelling, punctuation, translation), we lack the ability to understand your writing because we're not YOU. No one is right or wrong here, it's basic lack of communication..... There's a barrier and we're all guilty.....

stop trying to point the finger and go work on your controller.


----------



## bjfreeman (Dec 7, 2011)

As far as calling the controller a Buck Converter, the problems is if you take the controller box by itself it does not have a Buck Component to it. The buck is the Motor.
So it is appropriate you call the controller and motor a Buck system.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



frodus said:


> I can't find your book/pdf/article/link/schematic reference in any post I can find.


oh well, don't have time to go back and find them.


> You have a difficult time with effective communication of your ideas and have issues with writing correct english (bad grammar, spelling, punctuation, translation), we lack the ability to understand your writing because we're not YOU.


Agreed and I do the best I can.
however may I point out the link to the previous explanation is almost word for word the one you seem to understand.


> No one is right or wrong here, it's basic lack of communication..... There's a barrier and we're all guilty.....


I try my best not use Right and Wrong more show where there is erroneous information so it can be corrected.


> stop trying to point the finger .


I am not aware of finger pointing. unless you count showing discrepancies that effect how something works.


----------



## frodus (Apr 12, 2008)

bjfreeman said:


> As far as calling the controller a Buck Converter, the problems is if you take the controller box by itself it does not have a Buck Component to it. The buck is the Motor.
> So it is appropriate you call the controller and motor a Buck system.


Now that is something I agree with.

Now that we're all gravy, go take some pictures and post them!


----------



## bjfreeman (Dec 7, 2011)

frodus said:


> Now that is something I agree with.
> 
> Now that we're all gravy, go take some pictures and post them!


When I have the Bus up on a rack I will pull the boxes down and take scads of pictures.
what I am working is some java based intrumentation and a canbus with EVDO so you can see real time trip logs on my website as well as previous trips.


----------



## palmer_md (Jul 22, 2011)

bjfreeman said:


> what I am working is some java based intrumentation and a canbus with EVDO so you can see real time trip logs on my website as well as previous trips.


The website you have linked on your profile page is down. Has been for a while.

http://roadwarrior.free-man.com/


----------



## bjfreeman (Dec 7, 2011)

palmer_md said:


> The website you have linked on your profile page is down. Has been for a while.
> 
> http://roadwarrior.free-man.com/


how about that must have changes something when doing the certs the first of the month


----------



## Tesseract (Sep 27, 2008)

bjfreeman said:


> As far as calling the controller a Buck Converter, the problems is if you take the controller box by itself it does not have a Buck Component to it. The buck is the Motor.
> So it is appropriate you call the controller and motor a Buck system.


Uh-huh. So now you are arguing that the last 10 pages (100 posts!) of your threadjacking (especially ironic, given the origin of this thread) has only been over semantics? I don't think so, buck-o. Just in case you've forgotten - which is entirely possible, given what I am about to post - here's where this all started:



bjfreeman said:


> *The "Input" capacitance is part of the Source and has no effect in the Buck process.*
> The integration is from the Reactance(inductance) in the Circuit.
> *In a pure buck circuit there is a Source*, Switch, Diode, Inductance and load.


I mean, how do you expect anyone to take you seriously when you contradict yourself in the space of two sentences???

No matter, as you claim that:



bjfreeman said:


> ...I started building both Buck and Boost circuits in 85 and have many circuits under my belt. So I have a lot of experience.....


So I guess this like the old saw that a million monkeys sitting at a million typewriters will eventually write Hamlet?

You keep typing, bj... just keep on typing.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



TigerNut said:


> Now let's look back at post #72 in this "discussion":
> 
> You (bjfreeman) were replying to Tesseract, not Major, and this is obvious because Major hadn't even posted one thing in this thread at that point. The circuit was one that Tesseract had described in words, not a picture. So, "what happened" is that YOU f'ed up and attributed the wrong thing, in the wrong context, to the wrong person.


Thank you Tiger for posting this. It does appear to be the source of confusion to bjfreeman, or at least one of the possible sources. It does reassure me that others can see that I have not hidden, altered, edited or lied about the "diagram" in question.

I also feel it is totally unconscionable of bjfreeman to make those accusations towards me, call me a liar and then not offer up an apology after your post. But it is not surprising given that he has previously insulted me and called me names.

So for bjfreeman, I offer up a quote from Jack Nicholson. "Truth! You can't handle the truth."



TigerNut said:


> Following this discussion has been very interesting, and a good review of basic circuit theory.


I do get some feedback about these "discussions" with bjfreeman. Some, as you do, find it interesting and good review, or educational. Others find it amusing and usually have popcorn while reading. Others find it sad.

Thanks again,

major


----------



## bjfreeman (Dec 7, 2011)

Quote:
Originally Posted by *bjfreeman*  
_*The "Input" capacitance is part of the Source and has no effect in the Buck process.*
The integration is from the Reactance(inductance) in the Circuit.
*In a pure buck circuit there is a Source*, Switch, Diode, Inductance and load._


Tesseract said:


> I mean, how do you expect anyone to take you seriously when you contradict yourself in the space of two sentences???


How do you see this as a contradiction?
What, to you, defines a buck process?
what is the function of the Input capacitors?
hows is the buck process effected by the input capacitors?


----------



## palmer_md (Jul 22, 2011)

bjfreeman said:


> Quote:
> Originally Posted by *bjfreeman*
> _*The "Input" capacitance is part of the Source and has no effect in the Buck process.*
> The integration is from the Reactance(inductance) in the Circuit.
> ...


-The "Input" capacitance is part of the *Source*
-In a pure buck circuit there is a *Source*, Switch, Diode, Inductance and load.

If A is part of B and B is part of C than A is part of C.


----------



## bjfreeman (Dec 7, 2011)

palmer_md said:


> -The "Input" capacitance is part of the *Source*
> -In a pure buck circuit there is a *Source*, Switch, Diode, Inductance and load.
> 
> If A is part of B and B is part of C than A is part of C.


That is true.
so how do you answer
_*and has no effect in the Buck process*_


----------



## frodus (Apr 12, 2008)

This is where your communication skills, grammar, sentence structure is lacking.

I see what you're saying BJ, but your wording is very ambiguous (which is a big part of the problem in this thread).


----------



## bjfreeman (Dec 7, 2011)

palmer_md said:


> -The "Input" capacitance is part of the *Source*


I already stated it was part of the source, but what function does is play in the source was the question.


----------



## bjfreeman (Dec 7, 2011)

frodus said:


> This is where your communication skills, grammar, sentance structure is lacking....
> 
> I see what you're saying BJ, but your wording is very ambiguous..... which is a big part of the problem in this thread.


what do you see my saying .


----------



## TigerNut (Dec 18, 2009)

bjfreeman said:


> That is true.
> so how do you answer
> _*and has no effect in the Buck process*_


I'd answer that (like many others that have participated in this thread) with: *You're wrong*.

The purpose and effect of the input capacitors is to lower the effective impedance of the source so that, from the point of view of the switch, the source is more nearly ideal. An ideal or nearly ideal source is essential for efficient buck converter operation, and it's also required to keep the switch from getting fried due to voltage spikes caused by stray inductance in the source.

This is also why the freewheel diode needs to be located physically close to the switch. Stray inductance between the switch and the diode will kill the switch.

When I have a bit of time I'm going to make up a Spice model of this circuit, using as many realistic parameters and component values as I can find... and then we can see specifically what it means to leave out capacitance on the input side, in the presence of a battery with some finite impedance.


----------



## palmer_md (Jul 22, 2011)

bjfreeman said:


> I already stated it was part of the source, but what function does is play in the source was the question.



Your answer is in POST#56. This is the post you questioned and said that the capacitors are not required. Read post 56 carefully and follow the explanation. Don't just peruse the post, but really read it and you'll see the answer.


----------



## frodus (Apr 12, 2008)

bjfreeman said:


> what do you see my saying .


Please use properly formed sentences. Until then, I won't answer you.


----------



## major (Apr 4, 2008)

bjfreeman said:


> *The "Input" capacitance is part of the Source and has no effect in the Buck process.*
> The integration is from the Reactance(inductance) in the Circuit.
> *In a pure buck circuit there is a Source, *Switch, Diode, Inductance and load.





palmer_md said:


> -The "Input" capacitance is part of the *Source*
> -In a pure buck circuit there is a *Source*, Switch, Diode, Inductance and load.
> 
> If A is part of B and B is part of C than A is part of C.





bjfreeman said:


> That is true.
> so how do you answer
> _*and has no effect in the Buck process*_


It is your contradiction bjfreeman. 


Tesseract said:


> I mean, how do you expect anyone to take you seriously when you contradict yourself in the space of two sentences???


 You need to provide the "answer", not ask others to explain your contradiction.


----------



## bjfreeman (Dec 7, 2011)

TigerNut said:


> I'd answer that (like many others that have participated in this thread) with: *You're wrong*.


well at least you provide you reasoning so we can get clarification.
The focus of my statement was the buck process. This only happens in a series inductor, and is used, in application other than motors, to reduce the source voltage. 
the Buck process is the flux cutting adjacent wires causing a a reverse emf that bucks the emf from the source.
The motor is the Buck component and the load. *There is no buck device in the controller*
Based on the above, the input capacitors have no effect on the flux rising or the number of wires it crosses.


> The purpose and effect of the input capacitors is to lower the effective impedance of the source so that, from the point of view of the switch, the source is more nearly ideal. An ideal or nearly ideal source is essential for efficient buck converter operation, and it's also required to keep the switch from getting fried due to voltage spikes caused by stray inductance in the source.


The controller has no Buck component in it. *The buck process is in the motor*,* and the fact the motor is in series with the switch.*
You would not need those Humongous caps if the PWM was a constant.
The Caps are there to give Instantaneous Supply when the PWM changes it pulse width and supply more Current to the motor. Its function is to keep the supply voltage from sagging till the batteries can start supplying sufficient Current.
This is the same purpose of Cap banks on the supply side.
that are used in Commercial EV's.



> This is also why the freewheel diode needs to be located physically close to the switch. Stray inductance between the switch and the diode will kill the switch.


it is also a cost effective way to have the diode(across the motor terminals, electrically) in the controller, than having to have a separate box, so the Diode placed at the motor. I decided that it is best to curb the Current produced by the Reverse EMF to stay at the motor, since it reduces high currents and voltages radiating from unshielded cables in the motor loop.

This setup cost more and is harder to protect from improper installation, but I am not selling what I do.

i gave a real world test about how much inductance cable has and what the voltage would be. it is far below the reverse voltage rating of the Switch, used in these controllers.

the Reason the Diodes are provided in the devices (IGBT) is to protect the device from reverse EMF.
So there is no need to really have the Diode across the motor in the controller, except for cost of producing the controller.


> When I have a bit of time I'm going to make up a Spice model of this circuit, using as many realistic parameters and component values as I can find... and then we can see specifically what it means to leave out capacitance on the input side, in the presence of a battery with some finite impedance.


I will be interested in the configuration and the results.


----------



## bjfreeman (Dec 7, 2011)

frodus said:


> Please use properly formed sentences. Until then, I won't answer you.


that is why I flunked English.
Dyslexic have a problems with structure. as well as spelling, and punctuation.
you should see how many spelling errors the spell check shows before I post.
I respect your point of view and will not expect any more responses from you.
Thanks for you help so far.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

This post #56


Tesseract said:


> The input capacitor of the buck converter integrates the rectangular current waveform drawn by the switch into a triangular waveform which the impedance of the supply wiring converts into what is called the reflected ripple voltage.


The input capictor is there to supply instant current till the batteries can catch up. It is also there to reduce the number of discharge cycles of the batteries for short burst.
This is the same for capacitor Banks used on commercial EV's


> Thus the inductance and resistance of the battery loop wiring affects the level of observed ripple voltage. If the impedance of this loop is too high then the controller won't operate correctly, but that would be true _regardless of the amount of capacitance present!
> _


yes means you need a larger supply cable.


----------



## major (Apr 4, 2008)

bjfreeman said:


> Dyslexic have a problems with structure.


Maybe this is why you think you saw a diagram from me which never existed.


----------



## palmer_md (Jul 22, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> The input capictor is there to supply instant current


Hint: it works in two directions. It can both sink and source current.


----------



## bjfreeman (Dec 7, 2011)

major said:


> Maybe this is why you think you saw a diagram from me which never existed.


actually Dyslexics are great pattern recognizers. So a diagram is a pattern.


----------



## major (Apr 4, 2008)

bjfreeman said:


> actually Dyslexics are great pattern recognizers. So a diagram is a pattern.


So you should be able to go back and find that one.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



palmer_md said:


> Hint: it works in two directions. It can both sink and source current.


Yes if you have regen then it will sink. but you can't have Regen. With the circuits laid out and without additional components, Regen is not possible.
The Diode across the motor stops this. It would have to be disabled by a Switch in series with the diode.
Now if you mean they sink when charging from the batteries, I don't count that.


----------



## bjfreeman (Dec 7, 2011)

major said:


> So you should be able to go back and find that one.


enought to know the pattern has been changed in the previous ones.
How or why I don't know. 
Just it is not the same one.


----------



## palmer_md (Jul 22, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Yes if you have regen then it will sink. but you can't have Regen. With the circuits laid out and without additional components, Regen is not possible.
> The Diode across the motor stops this. It would have to be disabled by a Switch in series with the diode.


Nothing to do with regen!



bjfreeman said:


> Now if you mean they sink when charging from the batteries, I don't count that.


You should count that because this is exactly what we have been talking about. Were talking about inductance on the source. If you have a switch and you open it and there is inductance on the source (as small as it may be), you will get a spike on the switch. You need to sink this current somewhere and a capacitor is used to do this.


----------



## major (Apr 4, 2008)

bjfreeman said:


> enought to know the pattern has been changed in the previous ones.
> How or why I don't know.
> Just it is not the same one.


You're wrong. The record is intact. You can go back and see every post. None of my posts during that period show any edits. It is simply not possible for me to have altered any diagram. The only one I used on this thread at that point was the one you lifted from wikipedia and showed in post #57. I copied that and pasted it into my post #80. It is exactly the same as your attachment from post #57. There is no edit to my post #80 so I could have not altered the diagram. In post #99 you accuse me of the problematic model. There was no post from me in the interval between #80 and #99 which included any diagram or model. And the only diagram which I posted in the referenced thread was the one copied from frodus (exactly, no alterations) which I showed again in post #106.

TigerNut came up with a good explanation in his post #133.

You are wrong. You call me a liar and have no evidence to support it. You are wrong and need to blame something or somebody else so make up a lie of your own. Grow up.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



palmer_md said:


> Nothing to do with regen!
> You should count that because this is exactly what we have been talking about. Were talking about inductance on the source. If you have a switch and you open it and there is inductance on the source (as small as it may be), you will get a spike on the switch. You need to sink this current somewhere and a capacitor is used to do this.


Please read 1.5
http://www.ti.com/lit/an/slta055/slta055.pdf


----------



## palmer_md (Jul 22, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Please read 1.5
> http://www.ti.com/lit/an/slta055/slta055.pdf


Also read 1.1 to 1.4.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



palmer_md said:


> Also read 1.1 to 1.4.


Yes I read the whole pdf many times in the years, since 2006, it is my Switching folder.
Now the input Capacitors are those big bulky ones, they are electrolytic. That refers to 1.1 paragraph 3 & 4.
1.4 refers to my statement about the battery current not being as quick and the 1.5 use of Bulk capacitors.
Now we cleared that up.
What started this was my statement the input Capacitors have nothing to do with the buck process of the motor. The process does not change, the current coming into the motor is buck by the flux rising and cutting wires and causing a reverse EMF.
Now the results of the buck process are effected by the Source level
but my focus was on the process to clear up how Buck works.
once we agree on the process then we can talk about the results and all that effects it.


----------



## palmer_md (Jul 22, 2011)




----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> The motor controller (which we call a buck converter) does much the same thing by using the magnetic field in the motor. Whereas the transformer relies on AC to get the needed change in magnetic field, the motor controller uses PWM to create a changing current and therefore a changing magnetic field.
> 
> There must be a node and alternate path for the load current and the Free Wheeling Diode provides this. The load current (motor current) is the sum of the switch current (battery current) and the FWD current. The motor voltage is the average voltage or the battery voltage times the PWM %. Again, like the transformer, power into the motor controller is equal to the power out (neglecting loss). So at 50% PWM, the motor voltage is half the battery voltage and the motor current is twice the battery current.


I have been looking for a reference and finally found something to show current multiplication. I(sub_L) is the inductor current which is the motor current in our case. I(sub_in) is the input current which is battery current in our case. You can plainly see how the average motor current is greater than the average battery current.

from: http://www.industrial-electronics.c...nverters_and_Converter/31_Buck_Converter.html










Edit: I have attached another chart similar in nature from a link bjfreeman listed in his post #189. Interesting that the schematic there shows an input capacitor.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> I have been looking for a reference and finally found something to show current multiplication. I(sub_L) is the inductor current which is the motor current in our case. I(sub_in) is the input current which is battery current in our case. You can plainly see how the average motor current is greater than the average battery current.
> 
> from: http://www.industrial-electronics.c...nverters_and_Converter/31_Buck_Converter.html


You and I agree on the higher current. we disagree on how it is generated and the amount. the Average of both is the same, since the generated current is of short duration than the supply current. you should set up a test bed to check this out.

you article says it is higher, I agree, it is also shorter, so ther is no more power (engery) that was put in. this is do to the collapse of the flux in L1. it cuts across the windings. the calcuilation of how much is generated is voltage at the input of the coil time Q factor. which I have explained many times. Now if you want to label the Q factor as a multiplier that is ok with me.
what I took exception to was the Diode being characterize as a enabling Multiplier diode, instead of a voltage limiting to protect TR1.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> You and I agree on the higher current. we disagree on how it is generated and the amount. the Average of both is the same, since the generated current is of *short duration* than the supply current. you should set up a test bed to check this out.
> 
> you article says it is higher, I agree, it is also shorter, so ther is no more power (engery) that was put in. this is do to the collapse of the flux in L1. it cuts across the windings. the calcuilation of how much is generated is voltage at the input of the coil time Q factor. which I have explained many times. Now if you want to label the Q factor as a multiplier that is ok with me.
> what I took exception to was the Diode being characterize as a enabling Multiplier diode, instead of a voltage limiting to protect TR1.





> the Average of both is the same


Simply not true. It is obvious from the referenced chart that the FWD average current is higher than the average input current. And the average inductor current is higher than either average input or FWD current. When doing the average, you integrate over the period, not simply divide the sum of the max and min by two.

And I have witnessed this many times with a scope on actual tests. The referenced chart looks very much like what I have seen.

Look at it. The FWD current flows for the entire "off" period which in the example is longer than the "on" period. And as I have said before and as the reference indicates, the load (inductor) current is the sum of the input (battery) current and FWD current. So the motor current in the reference example is obviously more than double the input current. And as I and Tesseract both have explained to you, the power into the converter is equal to the power out of the converter (neglecting a small loss).

The FWD enables the current multiplication. Current multiplication would not occur without it. That is the primary function of the FWD. If it clamps some part of the circuit (which it does), that is a bonus.

You keep going on about Q. Maybe the circuit designer needs to know what that is, but 99.9999% of the readers here couldn't care less. There's nothing they can do about it. It comes with the motor and operational frequency of the controller, neither of which the user has any control over.

I see you quoted the diagram in your post. Good. Now there should be no doubt that I haven't altered it. 

So 2 months later are you finally ready to believe in this new science of current multiplication and why the motor cables may need to be larger than the battery cables?


----------



## ga2500ev (Apr 20, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Major,

You do realize that you and bjfreeman are talking about apples and gorillas right?

I answered this confusion in the other wire size thread that you referenced earlier.

Short version: The power is equal, the current is not. 

There are several ways to show it. The easiest is to see that the average motor voltage is less than than the battery voltage except at 100% PWM. Since the voltage is different, the power is equal and P=IV , the I on the motor side has to be more than the I on the source side to compensate for the lower V to get the same power.

The voltages on both sides are not the same, the currents are not the same, but the power is.

I hope this helps,

ga2500ev


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



ga2500ev said:


> Major,
> 
> You do realize that you and bjfreeman are talking about apples and gorillas right?
> 
> ...


Thanks ga,

I, along with other members, have mentioned this numerous times. And we have posted other references before. Hopefully this last one will do the trick. Having another member support our position will help the cause.

major


----------



## TigerNut (Dec 18, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Yes if you have regen then it will sink. but you can't have Regen. With the circuits laid out and without additional components, Regen is not possible.
> The Diode across the motor stops this. It would have to be disabled by a Switch in series with the diode.
> Now if you mean they sink when charging from the batteries, I don't count that.


But that's a critical point: You (or I, or anyone else) don't get to decide when a circuit component counts. If it's in the circuit, it counts all the time.

Similarly, the power delivered to the load is the load current multiplied by the voltage across the load. It doesn't matter whether the current comes from the switch or from the diode, and that is also why the buck regulator is as efficient as it is: the diode keeps the current that's built up in the inductor circulating (in the process using some of the stored energy in the inductor), and this means that the motor keeps delivering power even though there is no current coming from the source at that point.

Nobody is saying that the diode produces current out of the blue: Energy must be conserved (with a small loss due to resistance) and what the buck converter really does, is turn (Vbat x Ibat x dutycycle) into (Vbat/dutycycle) x ((Ibat x dutycycle) + (Idiode x (1-dutycycle))) , less that real-world resistive loss. And, as has been shown in Major's diagram, the instantaneous amplitude of Ibat and Idiode are nearly equal in a properly operating controller.

The reason, then, why the diode can be labeled as a "current multiplier" is that it ends up supplying the current for (1-dutycycle) of the time. When dutycycle is low (say 10%), (1-dutycycle) is 90% and so the diode effectively delivers 9 times as much current to the inductor and the load as the switch does.


----------



## TigerNut (Dec 18, 2009)

I realized I gave about a 3/4 complete view there.
What I labeled Ibat, should really be Iswitch.
The average battery current is Ibat=Iswitch/dutycycle, and when the switch is on the switch current is the sum of the battery current and the input capacitor current. The capacitor and the battery will share in the delivery of the switch current according to their respective admittances, and also depending on the size of the cap bank itself. If it's properly sized then the battery current will flow at a more or less constant level, given a constant duty cycle.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> I have been looking for a reference and finally found something to show current multiplication. I(sub_L) is the inductor current which is the motor current in our case. I(sub_in) is the input current which is battery current in our case. You can plainly see how the average motor current is greater than the average battery current.
> 
> from: http://www.industrial-electronics.c...nverters_and_Converter/31_Buck_Converter.html


lets back 
first this is what the article said:


> The buck converter circuit is the basis for several other similar circuits called forward converters. The buck converter circuit and the input and output voltages for this circuit are shown in Fig. 1. This circuit would be connected directly after the power transformer. From the diagram notice that this circuit is fairly simple in that it consists of a transistor, inductor, diode, and capacitor. When the transistor is turned on, power will flow directly to the output terminals. This voltage must also pass through the inductor, which will cause current to build up in it in much the same way that a capacitor charges. When the transistor is switched off, the stored current in the inductor will cause the diode to become forward bias, which will let it freewheel and allow the current to be delivered to the load that is connected to the output terminals.


and I agree. Now where did you come up with the explanation you gave.

Second: the complete circuit in a motor controller with motor would add the diagram below to the diagram at the top.

Now lets explain the whole system


----------



## DJBecker (Nov 3, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> The input capictor is there to supply instant current till the batteries can catch up. It is also there to reduce the number of discharge cycles of the batteries for short burst.
> This is the same for capacitor Banks used on commercial EV's
> 
> yes means you need a larger supply cable.


The primary reason for the input capacitor is to absorb the voltage spike that happens when the transistor stops conducting.

We have little concern about the initial sag when the transistor turns on, and it's too little capacitance to have a big effect on the average reflected ripple voltage. It's *far* too little capacitance to "reduce the number of discharge cycles". Do a quick calculation of how much energy is in a 5V discharge of 10,000uF (it's only 0.01 F). Or how long that capacitor bank can supply 100 amps.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> lets back
> first this is what the article said:
> and I agree. Now where did you come up with the explanation you gave.


My explanation does not contradict anything which can be found in the article. I was explaining the diagram. 

I think this post applies. It was directed to you in the 101 thread.


palmer_md said:


> Just like the electrical issues you are having on this site. We all can point to a common definition, but your interpretation of the definition is wildly different than everyone else.





bjfreeman said:


> Second: the complete circuit in a motor controller with motor would add the diagram below to the diagram at the top.


Not exactly. It was the complete system before you altered it. The motor controller uses the motor itself for the output inductor and therefore cannot use the output capacitor.



bjfreeman said:


> Now lets explain the whole system


The explanation stands.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> what I took exception to was the Diode being characterize as a enabling Multiplier diode, instead of a voltage limiting to protect TR1.





major said:


> The FWD enables the current multiplication. Current multiplication would not occur without it. That is the primary function of the FWD. If it clamps some part of the circuit (which it does), that is a bonus.


I found another web site with a Basics of Buck Converter tutorial. 



> The diode used in a switched regulator is usually referred to as the free-wheeling diode or sometimes as a catch diode. The purpose of this diode is not to rectify, but to direct current flow in the circuit and to ensure that there is always a path for the current to flow into the inductor.


ref: http://www.netlecturer.com/PEOnline/T01SMPS/p02BuckConv01.htm


----------



## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

I thought I would try to bend this thread back to useful information. 



Tesseract said:


> Ah, okay. Well, if the dc/dc converter was designed for use in an EV - where high reflected ripple is to be expected - then it should work fine. However, every one that I have seen - including the pricy Zivans - exposes its input capacitor directly to the HV input supply. Dumb.
> 
> Rebirth Auto sells an inductor that I spec'ed out specifically for protecting chargers and dc/dc converters, but you can do a decent enough job by simply coiling up one of the supply wires to the dc/dc converter about 100x. NB - that will be more practical to do with, say, 16awg wire rather than 10awg


How about the using one of the AC to DC converters that happens to work on DC? Are any of them known to work without issue? The most common would be the old Iota and Todd units. It seems that they should be built for the voltage to go to zero 120 times a second. 

Are any of the commonly available DC to DC converters close enough to being able to handle it that just a diode on the input will hide enough of the downside of the sawtooth to keep things happy? 

About 30 feet of 16 gauge wire isn't an impossible choice, only about 1 watt of heat spread across a lot of wire. Does it need any type of core or could I just use a spool of wire?


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I thought I would try to bend this thread back to useful information.


I just gave you positive reputation for that! 



EVfun said:


> How about the using one of the AC to DC converters that happens to work on DC? Are any of them known to work without issue? The most common would be the old Iota and Todd units. It seems that they should be built for the voltage to go to zero 120 times a second.


The Iota's are actually one of the worst offenders, here. It only takes a $5 inductor from DigiKey to protect them, though.

You are sort of on the right track, theoretically speaking, by considering the 120Hz ripple from the rectifier as being relevant. The part you missed is that the capacitor has an ac "resistance" (called reactance) that goes down with frequency. This is mostly irrelevant to the designer of a line-operated SMPS - the energy storage (0.5CV²) is all they are interested in - but at the switching frequencies of our motor controllers these capacitors look like dead shorts (at 8kHz a 1000uF capacitor has about 0.02 ohms of reactance). If the reflected AC ripple from the controller's operation is, say, 10V, then "500A" of AC current will flow through that capacitor. Needless to say, only the biggest, baddest film capacitors can take that kind of ripple (like the ones inside our controllers ).

If you put an inductor in series with the capacitor you then form a low pass filter with the effective ripple voltage divided by the ratio of the inductive reactance to the capacitive reactance. Let's say we pick a cheap powdered iron toroidal inductor rated for 100uH even when supplying 5A of DC current to the dc-dc converter input. The inductor's reactance of ~5 ohms at 8kHz will form a voltage divider with the capacitor's reactance of 0.02 ohms so that even 50V of ripple voltage riding on the pack won't hurt the capacitor (because it will only see 0.2V of the ripple).



EVfun said:


> Are any of the commonly available DC to DC converters close enough to being able to handle it that just a diode on the input will hide enough of the downside of the sawtooth to keep things happy?


No, they pretty much all need to be protected from controller ripple if used with either our or NetGain Controls' controllers. I don't know for sure, but I believe the Zilla's have both enough capacitance and a low enough ESR for said capacitance to not reflect too much ripple back onto the pack.

At any rate, the above inductor I used for the example is way larger than is needed to protect a typical dc-dc converter and even it only costs $12.



EVfun said:


> About 30 feet of 16 gauge wire isn't an impossible choice, only about 1 watt of heat spread across a lot of wire. Does it need any type of core or could I just use a spool of wire?


Just use the spool of wire - no core required.


----------



## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> You are sort of on the right track, theoretically speaking, by considering the 120Hz ripple from the rectifier as being relevant. The part you missed is that the capacitor has an ac "resistance" (called reactance) that goes down with frequency. This is mostly irrelevant to the designer of a line-operated SMPS - the energy storage (0.5CV²) is all they are interested in - but at the switching frequencies of our motor controllers these capacitors look like dead shorts (at 8kHz a 1000uF capacitor has about 0.02 ohms of reactance). If the reflected AC ripple from the controller's operation is, say, 10V, then "500A" of AC current will flow through that capacitor. Needless to say, only the biggest, baddest film capacitors can take that kind of ripple (like the ones inside our controllers ).
> 
> If you put an inductor in series with the capacitor you then form a low pass filter with the effective ripple voltage divided by the ratio of the inductive reactance to the capacitive reactance. Let's say we pick a cheap powdered iron toroidal inductor rated for 100uH even when supplying 5A of DC current to the dc-dc converter input. The inductor's reactance of ~5 ohms at 8kHz will form a voltage divider with the capacitor's reactance of 0.02 ohms so that even 50V of ripple voltage riding on the pack won't hurt the capacitor (because it will only see 0.2V of the ripple).


Please be patient with me here, as soon as I start thinking about inductors I usually want to bang my head against a wall. Clearly I won't be designing controllers. I'm having a hard time seeing how the input caps on an AC to DC converter can "see" the AC ripple behind the bridge. I would think they are blocked from seeing the down-side of that ripple (almost a dead short -- except for the reverse biased diode.) I don't doubt your experience, but I trying to figure out how that works. I can see how the input would be forced to charge in a bunch of little bursts near the peak of the ripple. I understand how a bunch of little bursts of high current increases heat -- 5 amps average in the form of 500 amps for 1% of the time would be 100 times the resistive losses (heating the poor caps.) However, in the real world all wiring adds both resistance and inductance. How does the loss get so high as to be troublesome without the "pull" half of AC?

I went looking at Mouser for inductor options and found a number of additional choices. I just happen to buy a lot more from Mouser, mostly because Digicrime has, or used to have, a minimum order price a bit high for the home hobbyist. The inductor seems to be an easy fix. I would suggest you add this info with the rough specs needed to any install FAQ Evnetics maintains and the Soliton manual. It quite easy to manage with the info you provided, and I doubt I'm the only person who's eyes start to glaze over when just told "you need a suitable inductor."

Are there other considerations are needed to make sure this ripple isn't an issue?


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



major said:


> I found another web site with a Basics of Buck Converter tutorial.
> 
> 
> 
> ref: http://www.netlecturer.com/PEOnline/T01SMPS/p02BuckConv01.htm


 Before we get into the heavy stuff lets cover some basics.
Normal Buck converters, want a stable voltage output, so ripple is a consideration.
Buck converters have a constant PMW range. It may vary some to compensate for the load.
Most Buck converters you see have a resistive load.




As a speed control for a motor
When the buck converter is supplying voltage to a inductive motor you don:t need to be concerned about ripple, as much. So you don't need the output Capacitor. The Additional inductance of the motor provided additional smoothing in fact you don't need the series inductor.
The PMW is varied to produce different Voltage outputs.
The Range the PMW varies is larger than in a Buck converter that provides a constant voltage or a varying load range.


I found your link to have some erroneous logic in it. Mostly to-do with the flow of current in the cycles.
Neat applet though I will try to expand it so show how a circuit controls a motor. And he logic in current flow.
Here is a PDF on the subject of SMPS.
http://ww1.microchip.com/downloads/en/AppNotes/01114A.pdf

As a side note the Freewheeling is the action of a diode that is forward biased. The key characteristic is it has a fast recovery.


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> Please be patient with me here, as soon as I start thinking about inductors I usually want to bang my head against a wall.


Join the club. Jeff, on the other hand, has very little love for software. Some periods of the Soliton development process has been spent with us two standing on mountain tops shouting at each other, so to speak... 



EVfun said:


> I would think they are blocked from seeing the down-side of that ripple (almost a dead short -- except for the reverse biased diode.) I don't doubt your experience, but I trying to figure out how that works.


Myep. In a perfect world the diode-cap-combo would "surf the peaks" so to speak, but since our world is far from perfect (especially when it comes to electrolyte capacitors) the internal resistance will convert most of those peaks not to charge but to heat. So what you have is not a capacitor in series with a diode, you have a capacitor and a resistance in series with a diode and the resistance will slow down the charging of the capacitor while producing an awful lot of heat.

If you were only charging the capacitor this wouldn't be a problem. Eventually the cap would have charged enough for staying above the peaks and no more heat would be produced, but in a DC/DC some bastard is using that charge and draining the voltage (how dare ya!  ) which means that the voltage will drop and the peaks will start to get through the diode again which will, again, start to heat things up.

Not even gonna speculate how much a diode would help (if any) since that's clearly Jeffs department, but yeah, you need an inductor to smooth out the current for those poor caps...


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I'm having a hard time seeing how the input caps on an AC to DC converter can "see" the AC ripple behind the bridge. I would think they are blocked from seeing the down-side of that ripple (almost a dead short -- except for the reverse biased diode.)


Qer's explanation is essentially correct: Putting a diode in front of the cap stops the motor controller (etc.) from drawing current back out of the capacitor during the troughs of the ripple waveform, but the peaks will still come through. In addition, the reduction in AC current through the capacitor will then depend on how much it is loaded - if lightly, then the ripple will be reduced to almost nothing, but if heavily there might not be any reduction at all. 



EVfun said:


> ...The inductor seems to be an easy fix. I would suggest you add this info with the rough specs needed to any install FAQ Evnetics maintains and the Soliton manual.


Legally speaking - though IANAL - I must be careful about giving detailed instructions on how to install other products in my Soliton Owner's Manual as I then make myself at least partially responsible for any failure, property damage, etc. that may result. Also, manufacturer's routinely change their products in ways that could render my advice moot, or worse, counterproductive. For example, rumor has it the new Iota "dc-dc converters" will no longer function on DC. Or maybe Zivan will finally add a $5 inductor in series with the output on all of their pricey chargers...

And then there are the misuses and abuses which customers might attempt such as buying the wrong kind of inductor because a specific part number I recommend is out of stock. 100uH? 100nH? What's the big difference (only about a 1000x change in inductance is all)???



EVfun said:


> Are there other considerations are needed to make sure this ripple isn't an issue?


Not really. The only other detail that is important, and which I address in the aforementioned Soliton Owner's Manual, is to run the battery cables next to other other over as much of the pack as possible and, of course, to the controller itself.


----------



## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> Before we get into the heavy stuff lets cover some basics.


Please start your own thread.


----------



## JRP3 (Mar 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I went looking at Mouser for inductor options and found a number of additional choices. I just happen to buy a lot more from Mouser, mostly because Digicrime has, or used to have, a minimum order price a bit high for the home hobbyist.


I've ordered from Digikey maybe $30 or less of small parts that were shipped cheaply in a small packing envelope.


----------



## EVfun (Mar 14, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

I see that DigiKey no longer has a minimum order requirement. If the DC to DC converter was small, not over 15 to 20 amps output, would this be a suitable choice too? I ask mostly because I know I don't understand the various rating on inductors all that well. It also looks like this $4 part from Mouser would do that job for a DC>DC with up to about 40 amps output (plus or minus based on minimum input voltage and efficiency.)


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



EVfun said:


> I see that DigiKey no longer has a minimum order requirement. If the DC to DC converter was small, not over 15 to 20 amps output, would this be a suitable choice too? I ask mostly because I know I don't understand the various rating on inductors all that well. It also looks like this $4 part from Mouser would do that job for a DC>DC with up to about 40 amps output (plus or minus based on minimum input voltage and efficiency.)



The drum inductor you picked from DigiKey is *bad* because it does not have a closed flux path (which means it will not only radiate EM noise everywhere, it will also efficiently receive it, too). The toroid inductor from Mouser, though, is perfect.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



DJBecker said:


> The primary reason for the input capacitor is to absorb the voltage spike that happens when the transistor stops conducting.
> 
> We have little concern about the initial sag when the transistor turns on, and it's too little capacitance to have a big effect on the average reflected ripple voltage. It's *far* too little capacitance to "reduce the number of discharge cycles". Do a quick calculation of how much energy is in a 5V discharge of 10,000uF (it's only 0.01 F). Or how long that capacitor bank can supply 100 amps.





taken from a Motor controller manual said:


> The Cap supplies the instantaneous current need of the Switch to overcome stray inductance in the Battery pack wiring.


can you refute one of your own member's publish works.
also read the pdf on capacitors in a switching circuit
http://www.ti.com/lit/an/slta055/slta055.pdf


----------



## TigerNut (Dec 18, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> can you refute one of your own member's publish works.
> also read the pdf on capacitors in a switching circuit
> http://www.ti.com/lit/an/slta055/slta055.pdf












As Major suggested: Start your own thread, with a suitable subject line, and make proper references, including appropriate notes as to the context, so that people will know what you're trying to figure out.

In case it's not clear: "You" is not a suitable form of address, when there are about a dozen folks participating in a discussion. Similarly, "a controller manual" does not convey enough context to establish what it is that needs to be communicated. Last: you didn't provide any indication what it might have been out of that TI app note (which is related to point-of-load computer power supply design, not high-power motor controllers) that supported the position you're trying to establish. 

And before you go there, you should be aware that, taking the appropriate context into account, that TI datasheet says exactly the same thing that Qer, Tesseract, and DJBecker are saying: 
1. You need some capacitance to counter the effect of input wiring inductance.
2. Reflected ripple current can be bad for other systems tied to the same battery, but input inductance can alleviate some of that badness, provided it doesn't negatively impact other performance considerations.


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> can you refute one of your own member's publish works


This is too rich! You are quoting my own manual to prove a point that all of us have been trying to prove to you for the last 100 posts!!!!



TigerNut said:


>


I couldn't have said it better myself!


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



TigerNut said:


> In case it's not clear: "You" is not a suitable form of address, when there are about a dozen folks participating in a discussion.


since I include the person name and their discussion, I would think that "you" would equate to the person that was quoted. Like you in the case would be TigerNut.



> Similarly, "a controller manual" does not convey enough context to establish what it is that needs to be communicated.


At least quote correctly, maybe that is part of your problem you don't see all that is written. "*taken from a Motor controller manual*" and "can you refute one of your own member's publish works."
So it from the solitron user manual.


> Last: you didn't provide any indication what it might have been out of that TI app note (which is related to point-of-load computer power supply design, not high-power motor controllers) that supported the position you're trying to establish.


The Position was provided by the person I quoted.
again you only read part of the PDF. It addresses both input and output Capacitance of a Switched ciruit.
So what document do you have to show the Difference a Power Switcher and a low power Switcher?


> And before you go there, you should be aware that, taking the appropriate context into account, that TI datasheet says exactly the same thing that Qer, Tesseract, and DJBecker are saying:
> 1. You need some capacitance to counter the effect of input wiring inductance.
> 2. Reflected ripple current can be bad for other systems tied to the same battery, but input inductance can alleviate some of that badness, provided it doesn't negatively impact other performance considerations.


First you again missed 
Originally Posted by *DJBecker*  
_The primary reason for the input capacitor is to absorb the voltage spike that happens when the transistor stops conducting.

We have little concern about the initial sag when the transistor turns on, and it's too little capacitance to have a big effect on the average reflected ripple voltage. It's *far* too little capacitance to "reduce the number of discharge cycles". Do a quick calculation of how much energy is in a 5V discharge of 10,000uF (it's only 0.01 F). Or how long that capacitor bank can supply 100 amps.

_
I spent some time readng the PDF against each point to make sure I was not missing something. I am not sure how you got that from the PDF.
1. it talks about how Bulk capacitors, are not good for ripple. which address and needing Ceramics on the input.
Saying you need capacitannce to counter the inductance is does not give a clear function of the Caps.
2. I saw no mention of reflected ripple current. so that must be an adlib.

IF you want to debate, at least get the facts straight.


----------



## bjfreeman (Dec 7, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> This is too rich! You are quoting my own manual to prove a point that all of us have been trying to prove to you for the last 100 posts!!!!


funny I have been saying it also apparently no one reads what I write. which explains why I can"t get my point accross.

and please lets not start a he said she said flaming sequence.


----------



## TigerNut (Dec 18, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> since I include the person name and their discussion, I would think that "you" would equate to the person that was quoted. Like you in the case would be TigerNut.


Except that the first quote was something posted by DJBecker, and the second was "taken from a Motor controller manual". Ergo, "you" was not sufficiently distinct.



bjfreeman said:


> At least quote correctly, maybe that is part of your problem you don't see all that is written. "*taken from a Motor controller manual*" and "can you refute one of your own member's publish works."
> So it from the solitron user manual.


That would be "Soliton" to the rest of us. While that was reasonably easy to assume based on the rest of the discussion, it wouldn't hurt to be explicit. Also, I'm not sure what either DJBecker or Tesseract would be common members of (other than this forum, of which you're also a member).



bjfreeman said:


> The Position was provided by the person I quoted.


DJBecker's position is one of protection for the transistor when it turns off, while yours is related to the instant when the transistor turns on. Seems like you could both easily come to a mutual understanding, since both effects are caused by non-zero input impedance (resistive and inductive) to the battery, and both are mitigated by using good capacitors at the input side of the switch.


bjfreeman said:


> again you only read part of the PDF. It addresses both input and output Capacitance of a Switched ciruit.
> So what document do you have to show the Difference a Power Switcher and a low power Switcher?


Hm. I think of myself as a reasonably careful reader.

I saw in the PDF that they mentioned using ceramics for their good ESR and self-resonant qualities, and that "bulk capacitance" (and specifically, electrolytics) wouldn't cut the mustard. Then they do an example that (from memory) involved 10A and dropping from 12V source to 3.3V load. They needed something like 70 uF, right? 

Let's do that calculation for a DC motor controller, at the worst case of 50% duty cycle (learned that from reading!):
Suppose a 200V battery, at 200A controller output current, 50% duty cycle, and 15kHz PWM frequency. Since the duty cycle is 50%, the power is approximately 20 kW, which is not a completely ridiculous situation.
I'm not sure what the maximum ripple voltage should be in this situation. I'll assume 1 volt and then see where we should go from there.
Cmin = 200 x 0.5 x (1 - 0.5) x 1000 / (15 x 1)
Cmin = 3333 uF.

So how large are 3333uF of 200V (at least! maybe we want some safety factor there, right?) ceramic capacitors? I found some AVX caps in their SM06 series where you can get 500V, 47 uF multichip modules. Still need like 70 of those, preferably arranged so as to minimize the inductance to the remainder of the power distribution system. Could be tough since they're about 2 inches by 1.38 inch... each.

The power dissipated due to the 1V ripple is going to be significant, even if the per-unit ESR is low. Since power dissipation in the caps is going to be proportional to the square of the ripple voltage, you'd be better off to double the capacitance and thereby halve the ripple voltage. This effectively halves the power lost (even assuming constant ESR).

Where this leads is that a LOT more capacitance will usefully reduce the ripple voltage to the point where the electrolytics can handle the ripple current. And with electrolytics you get way more capacitance per unit volume. Best of all, the industry makes specific capacitors for different kinds of power circuits:
http://industrial.panasonic.com/www-data/pdf/ABA0000/ABA0000TE7.pdf
So a bit of investigation will probably give you exactly the right kind of cap... you may have to read more than just the 100W power supply paper, because at really high power levels, there may be considerations not mentioned in that TI paper. And no, I don't know what those might be. My last switching power supply design was focused on getting 1000+ hours of use out of a AAA cell in a portable radio.



bjfreeman said:


> I spent some time readng the PDF against each point to make sure I was not missing something. I am not sure how you got that from the PDF.
> 1. it talks about how Bulk capacitors, are not good for ripple. which address and needing Ceramics on the input.
> Saying you need capacitannce to counter the inductance is does not give a clear function of the Caps.
> 2. I saw no mention of reflected ripple current. so that must be an adlib.


I don't think that "adlib" means what you think it means. See section 1.4 in the TI PDF:


> If reflected ripple is a concern, use a small (560 nH or less) input inductor. This is the single most effective way to confine ripple currents to the local input bypass caps. An input inductor can reduce the reflected ripple current by an order of magnitude. A single input inductor can be shared by multiple modules.
> At lower currents, this input inductor can take the form of a power ferrite bead. In a multiple module system, the use of a filter inductor at each module will help contain the noise generated by each module
> and keep it localized. It is one of the best ways to deal with beat frequencies caused by multiple modules operating at slightly different frequencies. Ensure the inductor current is below its saturation current rating.
> 
> During transient conditions, the use of an input inductor puts larger demands on input bulk capacitors. Take care when using input inductors as they will affect input capacitor selection.





bjfreeman said:


> IF you want to debate, at least get the facts straight.


OK dude... over to you.


----------



## Duncan (Dec 8, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Hi Tiger

You are wasting your time responding to bjfreeman - 
he just makes stuff up 
like his 12v 10Kw inverter for $395
and his 12v hydrogen generator powering a corvette engine without any storage

Give it up - chill out - and laugh at the funny man!


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



bjfreeman said:


> At least *quote correctly*
> [...]
> So it from the *solitron* user manual.


(my bolds)

Is it just me or is that combination slightly hilarious? Might be too much blood in my caffeine stream too (soon to be fixed)...


----------



## somanywelps (Jan 25, 2012)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> (my bolds)
> 
> Is it just me or is that combination slightly hilarious? Might be too much blood in my caffeine stream too (soon to be fixed)...


As long is this forked thread of mine is still going, I'd like to suggest a true 2000A controller to fill the game between Shiva's 3000A and Soliton 1's 1000A. 

You could even call it "Shiva Jr."


----------



## ga2500ev (Apr 20, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> The drum inductor you picked from DigiKey is *bad* because it does not have a closed flux path (which means it will not only radiate EM noise everywhere, it will also efficiently receive it, too). The toroid inductor from Mouser, though, is perfect.


This is helpful. I asked a bunch more questions in this thread that I started about inductor design/selection. And I do not want to hijack this one. So I'll limit myself to a question or three:

1. When designing, does one typically choose the max ripple current and frequency and then compute the inductor value from those, or select the inductor and choose the frequency that makes the maximum allowed ripple current to work?

2. How do you use the current ratings quoted with these inductors? All 40A saturation current inductors put the switching frequency in the megahertz range. So what exactly would you modify to get high current at a reasonable switching frequency without 80% ripple current?

3. When selecting (or winding ones own) do you pick AWG gauge that can handle the average or peak current of the converter? I still haven't figured out how these 40-50A circuits use inductors that have what looks like 18 gauge wire.

I hope this thread has staying power. I'm learning even more than I already knew. Thanks for everyones input.

ga2500ev


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



TigerNut said:


> DJBecker's position is one of protection for the transistor when it turns off, while yours is related to the instant when the transistor turns on. Seems like you could both easily come to a mutual understanding, since both effects are caused by non-zero input impedance (resistive and inductive) to the battery, and both are mitigated by using good capacitors at the input side of the switch.


Well put, TigerNut.



TigerNut said:


> ...Suppose a 200V battery, at 200A controller output current, 50% duty cycle, and 15kHz PWM frequency. Since the duty cycle is 50%, the power is approximately 20 kW, which is not a completely ridiculous situation.
> I'm not sure what the maximum ripple voltage should be in this situation. I'll assume 1 volt and then see where we should go from there.
> Cmin = 200 x 0.5 x (1 - 0.5) x 1000 / (15 x 1)
> Cmin = 3333 uF.


This equation only applies to the *output* ripple, because you are sizing the inductor yourself (something the poor schmuck designing a motor controller doesn't get to do!) to produce a certain amount of ripple current (typically 40% of the DC load current). You then select the output capacitor's ESR and capacitance to produce a certain amount of ripple voltage (usually less than 1% for "power supply" applications to as much as 20% in battery chargers).

On the input side of things the situation is even worse for the poor engineer as we typically have no idea what the analogous inductance will be (i.e. - that of the source, rather than the load), so we typically make two simplifying assumptions: 1) that the capacitor will have to supply all of the current during the switch on time and, 2) we have to pick a voltage droop during the switch on time which we think is acceptable for both the source and the feedback loop (to prevent instability in the latter).

The source is a battery pack so the amount of ripple is irrelevant to it - as long as the current drawn from it is within spec it doesn't really care what its terminal voltage is at. Other devices powered by that pack might care, but we can only do so much falling on our sword in a, say, $3000 motor controller to protect a, say, $200 dc-dc converter from ripple (i.e. - it is cheaper to add a $5 inductor to the latter than another $300 worth of capacitors to the former to get the exact same result - protecting the dc-dc converter from the motor controller's reflected ripple).

At any rate, you can combine the above two simplifying assumptions into a _heuristic_ (or "rule of thumb") of "1uf/A" of load current, assuming reasonable, but not exceptional, care is employed to minimize capacitor ESR, feedback loop stability and switching node impedance (i.e. - inductance and resistance in the loop between capacitor, switch and freewheeling diode).

Buck converters are extremely simple circuits with all sorts of hidden traps and pitfalls, especially at the kiloamp+ level, and this is just a "first year engineering student" kind of treatment on them...


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



somanywelps said:


> As long is this forked thread of mine is still going, I'd like to suggest a true 2000A controller to fill the game between Shiva's 3000A and Soliton 1's 1000A.
> 
> You could even call it "Shiva Jr."


As in a direct competitor to the Z2K? Nah, the market for that is around 20 units per year. One extreme niche product - the Shiva - is enough balance sheet pain for a company our size.


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



ga2500ev said:


> This is helpful. I asked a bunch more questions in this thread that I started about inductor design/selection. And I do not want to hijack this one. So I'll limit myself to a question or three:


Don't feel bad about hijacking *this* thread - it started as a hijack of _somanywhelp_'s thread, which was then hijacked by the ineffably obnoxious _bjfreeman_ so one more hijacking would just be keeping in the spirit of things... 



ga2500ev said:


> 1. When designing, does one typically choose the max ripple current and frequency and then compute the inductor value from those, or select the inductor and choose the frequency that makes the maximum allowed ripple current to work?


Depends on whether you are trying to use an off-the-shelf inductor or you are going to wind your own, but either way you generally want to pick a "reasonable" switching frequency for the current/voltage levels involved.




ga2500ev said:


> 2. How do you use the current ratings quoted with these inductors? All 40A saturation current inductors put the switching frequency in the megahertz range. So what exactly would you modify to get high current at a reasonable switching frequency without 80% ripple current?


The two fundamental specifications that help you select an inductor quickly are Al ("A-sub-L") and NI (amp-turns). The former gives you the inductance per turn squared (typically in nH/T²) while the latter is an indication of the power handling capability of the core.

For example, the core I spec'ed for Rebirth Auto for protecting dc-dc converters and chargers from ripple has an NI of 650 at "rated" DC current and an Al of around 140nH/T² at the same. The NI spec means I can wind a 10A inductor with 65 turns (which will be ~592uH) or a 25A inductor with 26 tunrs (for ~95uH), etc.

Inductors rated for DC current (ie - filter chokes, buck or boost inductors, etc.) that are off the shelf will typically give you the current at which the inductance has fallen by 20% and *that* is the maximum current to use. Note that the AC ripple causes heating in the core so the right core material for the switching frequency is also important. Rarely do you get detailed information on core material with off the shelf inductors, however, but it could be the difference between a 30C rise in core temp - which is good - to a 100C rise, which is almost universally bad.




ga2500ev said:


> 3. When selecting (or winding ones own) do you pick AWG gauge that can handle the average or peak current of the converter? I still haven't figured out how these 40-50A circuits use inductors that have what looks like 18 gauge wire.


Neither - you use the RMS current. That said, you size the wire for an acceptable amount of voltage drop which usually results in a much higher resistance per unit length than what would be tolerable for house wiring applications and the like. Also, the enamel insulation on magnet wire is rated for much higher operating temperature than the thermoplastic insulation used in "hookup" wire.


----------



## JRP3 (Mar 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



ga2500ev said:


> 3. When selecting (or winding ones own) do you pick AWG gauge that can handle the average or peak current of the converter? I still haven't figured out how these 40-50A circuits use inductors that have what looks like 18 gauge wire.


If the inductor is going on the input side of the converter it's not seeing 40 amps for a 40 amp DC/DC, but much less depending on pack voltage.


----------



## TigerNut (Dec 18, 2009)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Buck converters are extremely simple circuits with all sorts of hidden traps and pitfalls, especially at the kiloamp+ level, and this is just a "first year engineering student" kind of treatment on them...


I, for one, appreciate your willingness to let us poke under the hood, as it were, and get some insights into the next level of complexity that needs to be addressed, to go from a proof-of-concept construction to one that might last for more than a couple of minutes at high load.

With any well designed and built product there are usually lots of tweaks in the hardware, software and mechanical construction to deal with issues that wouldn't be thought significant by a neophyte, and it's *that* stuff that makes a good product worth its price.


----------



## palmer_md (Jul 22, 2011)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



TigerNut said:


> I, for one, appreciate your willingness to let us poke under the hood, as it were, and get some insights into the next level of complexity that needs to be addressed, to go from a proof-of-concept construction to one that might last for more than a couple of minutes at high load.
> 
> With any well designed and built product there are usually lots of tweaks in the hardware, software and mechanical construction to deal with issues that wouldn't be thought significant by a neophyte, and it's *that* stuff that makes a good product worth its price.


+1 Thanks for your continued support and participation in the EV community.


----------



## ga2500ev (Apr 20, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Don't feel bad about hijacking *this* thread - it started as a hijack of _somanywhelp_'s thread, which was then hijacked by the ineffably obnoxious _bjfreeman_ so one more hijacking would just be keeping in the spirit of things...
> 
> Depends on whether you are trying to use an off-the-shelf inductor or you are going to wind your own, but either way you generally want to pick a "reasonable" switching frequency for the current/voltage levels involved.


I see a lot of COTS inductors quoted at a 100Kh switching frequency. I had figured to work somewhere in the 5KHz to 10KHz ballpark. The crucial equation seems to be:

L = V * Ton / Iripple

Which indicates that the higher the voltage and switch on time (affected by frequency and duty cycle), and the lower the ripple, the higher the inductance needs to be.

In my thread, which BTW I'm happy to occupy if anyone comes to visit it, I give the example of a DC/DC converter, 144V max input, and 2A ripple current @ 14V output. I tried computing the frequency for a 1 uH inductor with a 83A saturation current and got a frequency in the 4 MHz range! Ouch! So operating on your suggestion I'm looking for:

L = 144V * 9.7 uS / 2A

where the 9.7 uS is the Ton time based on a 10 kHz switching frequency and a 9.7% duty cycle for the 144V to 14V conversion. So...

L = 700 uH

Digikey's parametric search is pretty good. So let's take a look and out pops this toroid. According to the datasheet
The rated current of 3.4A gives a 30C temp rise and effective inductance at that rated current is 370.7 uH. At 40A this one looks like a smoke bomb to me.



> The two fundamental specifications that help you select an inductor quickly are Al ("A-sub-L") and NI (amp-turns). The former gives you the inductance per turn squared (typically in nH/T²) while the latter is an indication of the power handling capability of the core.
> 
> For example, the core I spec'ed for Rebirth Auto for protecting dc-dc converters and chargers from ripple has an NI of 650 at "rated" DC current and an Al of around 140nH/T² at the same. The NI spec means I can wind a 10A inductor with 65 turns (which will be ~592uH) or a 25A inductor with 26 tunrs (for ~95uH), etc.


This is helpful to a point. I can see that the datasheet you specified has much better parameters than the one I just got from Digikey. However, I can see that I must have unrealistic expectations because even the core you specified cannot produce a 700 uH inductor @ 40A. The voltage is fixed in the equation. L has to be lower. So it looks like the tunable parameters are Ton (and therefore frequency) and Iripple. I'm figuring that a 5% ripple spec is unrealistic because with a relatively long Ton and a high voltage, the current has to be able to shift significantly as the inductor charges. So the two spec changes I can make are upping the frequency and widening the allowable ripple current. So back to the drawing boards. I saw an example supply that allowed for 30% Iripple and ran at 100 kHz. Let's re-run the numbers:

L = 144V * 972 ns / 12A -> 11.66 uH

Now it looks like we're cooking with gas! Back to our datasheet shows that the 10 uH one has some promise with a rated current of 20A.


> Inductors rated for DC current (ie - filter chokes, buck or boost inductors, etc.) that are off the shelf will typically give you the current at which the inductance has fallen by 20% and *that* is the maximum current to use. Note that the AC ripple causes heating in the core so the right core material for the switching frequency is also important. Rarely do you get detailed information on core material with off the shelf inductors, however, but it could be the difference between a 30C rise in core temp - which is good - to a 100C rise, which is almost universally bad.


What's the cutoff? Looks like the Burns datasheet spec is close on your marks. The 20A rating is for a 30C rise. The dropoff is 33% at the rated amperage. If I spec using amps and figuring the the RMS amperage is going to be about 45A, then the contenders disappear off the map. It does look like the core you specified can handle 40A at 10 uH.

Of course upping the ripple current will be hell on the output caps. What's a reasonable top range for the frequency? The higher it cranks up, the lower the ripple current, and more flexibility on the inductor. Of course now the switch is going to be pounded.

Some days this type of design work seems like juggling chainsaws... 

I know I should simply learn to be happy with a 20A inductor that works, and at least a clue of how to pick it, and use it. But how to designers fiddle when the required amperage goes up? I see JackBauer and Valerun building 200V/50A 10kW chargers. But I have absolutely no clue how they are getting inductors without burning everything up. The only clue I've been able to find is in one of valerun's schematics which specifies 300-400 uH with less than 30% saturation at max current. That's a 300 uH 150A saturation inductor. It's like looking for a unicorn.



> Neither - you use the RMS current. That said, you size the wire for an acceptable amount of voltage drop which usually results in a much higher resistance per unit length than what would be tolerable for house wiring applications and the like. Also, the enamel insulation on magnet wire is rated for much higher operating temperature than the thermoplastic insulation used in "hookup" wire.


Need to think about how to get my hands on some of that.

and finally...



JRP3 said:


> If the inductor is going on the input side of the converter it's not seeing 40 amps for a 40 amp DC/DC, but much less depending on pack voltage.


I know this is a controller thread and so the inductor would be on the input side. I'm actually asking questions about voltage converters in general, where an inductor will be in place of the motor. And so it actually has to be able to take on the full output current presuming it's a buck or flyback configuration.

ga2500ev


----------



## Salty9 (Jul 13, 2009)

Thanks for the Ludens link. I'm lurking on the edge of the electrical abyss.


----------



## somanywelps (Jan 25, 2012)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> As in a direct competitor to the Z2K? Nah, the market for that is around 20 units per year. One extreme niche product - the Shiva - is enough balance sheet pain for a company our size.


Yeah, that does make sense.

The only other thing I could think of is pulling a netgain and having shiva's software limited to 2K (iirc from your other thread, much of the cost was R&D)and unlockable for extra $$.


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



somanywelps said:


> The only other thing I could think of is pulling a netgain and having shiva's software limited to 2K (iirc from your other thread, much of the cost was R&D)and unlockable for extra $$.


Well. Problem is, you can't cut the price on Shiva much or there won't be any margin left at all. Of course, the price tag could be kept at todays levels with the current limited to 2k and then put an additional tag on unlocking the last 1kA... 

SOMEHOW I don't think that would be very populair, no?


----------



## somanywelps (Jan 25, 2012)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> Well. Problem is, you can't cut the price on Shiva much or there won't be any margin left at all. Of course, the price tag could be kept at todays levels with the current limited to 2k and then put an additional tag on unlocking the last 1kA...
> 
> SOMEHOW I don't think that would be very populair, no?


Unlikely


----------



## Yukon_Shane (Jul 15, 2010)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Qer said:


> Well. Problem is, you can't cut the price on Shiva much or there won't be any margin left at all. Of course, the price tag could be kept at todays levels with the current limited to 2k and then put an additional tag on unlocking the last 1kA...
> 
> SOMEHOW I don't think that would be very populair, no?


Any reason a person couldn't just put two soliton1's together? It seems like a simpler solution to getting 2,000 amps then designing a whole new controller.

Maybe you could even build a "master/slave" function into future software? I would assign this to the low priority file myself but it might make sense at some point.


----------



## Qer (May 7, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Yukon_Shane said:


> Any reason a person couldn't just put two soliton1's together? It seems like a simpler solution to getting 2,000 amps then designing a whole new controller.


They would have to be synchronized which would've had been added from the start, but since it wasn't... 

I think there's a few that has used two S1s in parallel already, but they use two motors too. One per controller...


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



somanywelps said:


> ...The only other thing I could think of is pulling a netgain and having shiva's software limited to 2K (iirc from your other thread, much of the cost was R&D)and unlockable for extra $$.


No, it's the exact opposite situation with Shiva - most of the cost is in parts and very little was spent on development. In fact, up until recently I flat out refused to make a "racing controller" because I couldn't think of a way to do it without a total redesign, and I wasn't going to put that much effort into something we would sell so few of (especially since the Z2K was back on the market again).

As for, say, cutting a Shiva in half, that wouldn't work out too well. The existing Shiva design has 1320A of ripple current capacity (meaning it can deliver 2640A of motor current continuously) and 4800A of IGBT current capacity (derated to 3000A because it is harder to ensure good sharing as the number of IGBTs in parallel goes up). If I cut that in half I would have a controller that could easily do 2000A (the corollary to the previous statement being that less IGBTs in parallel means less derating of them) but my capacitor bank would only be capable of supporting 1320A of continuous motor current - hardly better than a Soliton1. But if I increase the number of capacitors to balance them out better against the IGBTs I end up having a lot of space inside the case where more IGBTs could go, and so that's how you end up with a Shiva...


----------



## steven4601 (Nov 11, 2010)

Yukon, if your going to connect two (DC) motor controllers in parallel, do not forget to bring a video camera 

Sad that so little people understand anything about electronics. 

unsubscribe


----------



## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



ga2500ev said:


> I see a lot of COTS inductors quoted at a 100Kh switching frequency. I had figured to work somewhere in the 5KHz to 10KHz ballpark. The crucial equation seems to be:...


Man, you are all over the map here. What, exactly are you trying to do? It appears to be a DC-DC converter but you have to be more specific - is this a flyback transformer secondary, the filter choke for a buck-derived topology (forward, half-bridge, push-pull, full-bridge), or the resonating inductor for a soft-switching topology or what?



ga2500ev said:


> In my thread, which BTW I'm happy to occupy if anyone comes to visit it, I give the example of a DC/DC converter, 144V max input, and 2A ripple current @ 14V output. I tried computing the frequency for a 1 uH inductor with a 83A saturation current and got a frequency in the 4 MHz range! Ouch! So operating on your suggestion I'm looking for:
> 
> L = 144V * 9.7 uS / 2A
> 
> where the 9.7 uS is the Ton time based on a 10 kHz switching frequency and a 9.7% duty cycle for the 144V to 14V conversion. So...


This is why the buck - without a transformer - is not such a good choice when you need to step down a voltage more than 10:1 - the on time is ridiculously short. That said, you shouldn't be trying to get the ripple below 20% with just the inductor anyway.

At any rate, you are going to have to use a transformer - you should, anyway, if this is for recharging the 12V battery with the traction pack in an EV - and you need to run at a higher frequency than 10kHz. For an SMPS in the 300W to 600W range I like to use 100kHz. Below 100W I like to use 250kHz. Rarely do I feel the need to run at higher than 250kHz, even at very low wattage levels (ie - like for a gate driver power supply), but I've run 10W flybacks at around 400kHz or so.

A short on time is also going to demand a lot more filter capacitance, btw.



ga2500ev said:


> Some days this type of design work seems like juggling chainsaws...


Yep. And about as unforgiving if you are careless, too 



ga2500ev said:


> I know I should simply learn to be happy with a 20A inductor that works, and at least a clue of how to pick it, and use it. But how to designers fiddle when the required amperage goes up? I see JackBauer and Valerun building 200V/50A 10kW chargers.


Neither "jackbauer" nor "valerun" used what I would call a rigorous design process to select inductors for their chargers. The old saying "it's better to be lucky than good" only applies if you don't need to repeat your performance 

As I recall, jackbauer got his inductor from an old UPS, which was a good place to look. You generally want to use something that has a similar power output as potential source of parts, then if you can figure out what frequency it ran at you should be good to go.


----------



## ga2500ev (Apr 20, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Man, you are all over the map here. What, exactly are you trying to do? It appears to be a DC-DC converter but you have to be more specific - is this a flyback transformer secondary, the filter choke for a buck-derived topology (forward, half-bridge, push-pull, full-bridge), or the resonating inductor for a soft-switching topology or what?


The three typical uses of inductors in EV electronics: motor controller, DC/DC converter, and battery charger. I'm trying to understand the selection of inductors for switching power electronics in general, with those three as specific targets.




> This is why the buck - without a transformer - is not such a good choice when you need to step down a voltage more than 10:1 - the on time is ridiculously short. That said, you shouldn't be trying to get the ripple below 20% with just the inductor anyway.


I'm really glad that you keep posting, because every time you post, I learn something. I've been looking at flybacks, and running into the same issues of understanding parts selection. This Fairchild Application Note has been enlightning with a handful of rules of thumb. In short an EE or EI ferrite core properly sized to the output wattage of the target.


> At any rate, you are going to have to use a transformer - you should, anyway, if this is for recharging the 12V battery with the traction pack in an EV - and you need to run at a higher frequency than 10kHz. For an SMPS in the 300W to 600W range I like to use 100kHz. Below 100W I like to use 250kHz. Rarely do I feel the need to run at higher than 250kHz, even at very low wattage levels (ie - like for a gate driver power supply), but I've run 10W flybacks at around 400kHz or so.


More rules of thumb. So in these cases do you switch to a non-toroid core with an air gap?



> A short on time is also going to demand a lot more filter capacitance, btw.


I figured this out. It seems from my new formula:

Iripple = Vout / (f * L)

that Vout being the determining factor is the reason that flybacks are the configuration of choice when Vout is too low. Because the on time is too short in this case to keep the ripple current down. 




> *(Juggling chainsaws...)* Yep. And about as unforgiving if you are careless, too


That's the reason I'm trying to understand the design principles instead of just pulling a toroid from the junkbox and throwing it in.




> Neither "jackbauer" nor "valerun" used what I would call a rigorous design process to select inductors for their chargers. The old saying "it's better to be lucky than good" only applies if you don't need to repeat your performance
> 
> As I recall, jackbauer got his inductor from an old UPS, which was a good place to look. You generally want to use something that has a similar power output as potential source of parts, then if you can figure out what frequency it ran at you should be good to go.


I actually ripped a small APS UPS apart last week. Had what looked like a flyback transformer with several sets of leads. Since it was a 120V to 12V battery charger, it's likely that the primary/secondary ratio is in the right ballpark. Need to figure out which is which through. I guess a multimeter for continuity first then pumping some low voltage AC through a pair of continuous leads and measuring the voltage on the output would give a good idea even though technically a flyback transformer is a dual coupled inductor that expects only one of the primary/secondary to operate at any one point in time.

Thanks so much for the input. I hope to get to a point where I don't feel like a total dufus when it comes to power magnetics.

ga2500ev


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## Yukon_Shane (Jul 15, 2010)

steven4601 said:


> Yukon, if your going to connect two (DC) motor controllers in parallel, do not forget to bring a video camera
> 
> Sad that so little people understand anything about electronics.
> 
> unsubscribe


I didn't realize there was an electronics prerequisite to asking a question.

Seeing as my understanding of this topic is clearly limited perhaps you could take a second to explain why it won't work so that I could learn something.

I have a basic understanding of how a dc motor controller works but your correct that I'm far from an expert.


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



ga2500ev said:


> The three typical uses of inductors in EV electronics: motor controller, DC/DC converter, and battery charger. I'm trying to understand the selection of inductors for switching power electronics in general, with those three as specific targets.


Oy. Inductor and transformer design is the deep end of the SMPS pool... I don't think I could explain how to design them in a post even if you paid me. I'll try to give you a couple of pointers but - like pretty much everything else in life - if you really want to learn this you'll have to plow through the material yourself.

The first selection criterion is whether the core of the inductor/transformer is expected to store energy or not. Applications that need the core to store energy are the flyback "transformer", any filter inductor, and the inductor in all of the non-isolated topologies. If the answer is "yes" then you need a core with an air gap. If the core material is ferrite then it needs to literally have a gap cut into it (preferably the center pole, if possible, to contain the fringing flux; I'm guessing that made little sense, and this is just *one* of the bizarro bits about magnetics design!), otherwise, use a material with a "distributed" air gap, such as powdered iron, molypermalloy powder, etc. If you are trying to pick a COTS (commercial off-the-shelf) inductor then look for one that has a DC current rating; a core without an air gap - no matter how big it is - will not be able to tolerate DC at all.

Note that if you are designing a true transformer then you DO NOT want an air gap; indeed, you want the so-called 'magnetizing inductance' to be as high as possible, so that the no-load current is as low as possible, but I digress once again...

The second consideration is one I mentioned before - how many amp-turns (NI) is needed? You probably don't know how many turns are needed, but you should have a fair idea of the current. Know that if you need to design a filter inductor to carry, say, 83A, then a core with an NI rating of 60 ain't gonna cut it!

The third consideration is the ripple current, or the AC component of the total current, which the inductor must carry. The peak of the ripple must not cause the inductor to saturate (ie - exceed its NI rating). There is no hard-rule for selecting how much ripple to design your inductor for, but it should be apparent that there is no free lunch here - less inductance results in higher peak ripple current at a given switching frequency (more accurately: a given on time). NB - a corollary to NI is Volt-Seconds (or V-microseconds). A given core will be able to support x volts for y time; a larger core will be able to support a higher voltage for the same time, or the same voltage for a longer time.

The fourth consideration is the amount of inductance which depends on the switching frequency and the peak voltage or current. If you find that a core is too small to support the required Vs or NI, then you can try increasing the frequency. If you find that the frequency is outside of the ranges I previous suggested, then you need to pick a bigger core!

On a more practical note, I can almost guarantee you won't find any COTS inductors suitable for 80A+ of current - COTS inductors are made for small SMPS applications like National Semiconductor's "Simple Switcher" series (now part of TI - which is almost heretical to people like me). At this current level you are expected to design your own inductor or transformer. 

BTW - I've probably missed a few things... like I said in the beginning, I can't possibly explain everything in a forum post!



ga2500ev said:


> I'm really glad that you keep posting, because every time you post, I learn something. I've been looking at flybacks, and running into the same issues of understanding parts selection. This Fairchild Application Note has been enlightning with a handful of rules of thumb. In short an EE or EI ferrite core properly sized to the output wattage of the target.


You can use any core geometry you want for a flyback - some are better suited to a given application than others, of course - but the one constant is that the core will always have a gap (it's not really a transformer, hence my use of quotes above; more like a coupled inductor, as the primary and secondary never conduct at the same time).



ga2500ev said:


> I actually ripped a small APS UPS apart last week. Had what looked like a flyback transformer with several sets of leads. Since it was a 120V to 12V battery charger, it's likely that the primary/secondary ratio is in the right ballpark. Need to figure out which is which through. I guess a multimeter for continuity first then pumping some low voltage AC through a pair of continuous leads and measuring the voltage on the output would give a good idea even though technically a flyback transformer is a dual coupled inductor that expects only one of the primary/secondary to operate at any one point in time.


It seems I just explained something you already figured out... oh well, not going to delete it now.

The flyback is rarely used above 300-400W because of the high peak current and voltage stress it places on the switch and rectifier; that UPS almost certainly used the half-bridge or maybe the two-switch forward instead. At any rate, you can certainly use a multimeter to identify the windings, and then a low AC voltage to determine the transformation ratio of said windings. Don't try to apply more than 1V of 60Hz AC to a high frequency transformer or you might cause it to saturate.



ga2500ev said:


> Thanks so much for the input. I hope to get to a point where I don't feel like a total dufus when it comes to power magnetics.


That will take years, if not decades. I mean, I still learn more subtleties and whatnot about magnetics every time I design them. For example, I just learned from experience why planar transformers aren't nearly as cool as they would appear to be (in short: high leakage inductance).

BTW - leakage inductance is the uncoupled inductance in a transformer. You measure it by shorting together any one winding then measuring the inductance across any other winding. In a perfect transformer all flux is linked to all windings and there will be no leakage inductance, but transformers are never perfect so there will always be some flux which is not coupled to any other winding; this flux stores energy that zaps the switch or the rectifier when either turns off. So-called "soft switching" or resonant and quasi-resonant topologies attempt to use the leakage inductance to do something useful, but now we are leaving the pool and going straight to the ocean coast with a mean riptide going...


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## Tesseract (Sep 27, 2008)

Yukon_Shane said:


> I didn't realize there was an electronics prerequisite to asking a question.
> 
> Seeing as my understanding of this topic is clearly limited perhaps you could take a second to explain why it won't work so that I could learn something.
> 
> I have a basic understanding of how a dc motor controller works but your correct that I'm far from an expert.


Kind of a bizarre post which is sure to haunt steven4601, since I've caught him making some pretty amateur mistakes with his homebrew inverter. Ah well, none of us are so experienced in all facets of electronics that we can't use a little bit of help from someone else. This shit tends to come back and haunt you when you least expect it...


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## EVfun (Mar 14, 2010)

There is not electronics prerequisite to asking a question, someone just wasn't being very nice. I am going to attempt a description of what happens as a motor is started from zero rpm. 

The transistors in the controller turn on and current starts flowing into the motor. As long as the transistors are ON the voltage on the motor and the current through the motor continue to rise. At low rpm the motor will pass a huge amount of current at very low voltage so quickly the current rises to the maximum the transistors in the controller can handle. The transistors are turned OFF by the current limit circuit. The current continues flowing in the motor through a set of diodes in the controller (called the freewheel diodes) and the current slowly falls. A tiny fraction of a second later the transistors turn back ON and the current begins rising. The current limit is reached again and the transistors are turned OFF, allowing the current to slowly drop while flowing through the freewheel diodes. This process repeats thousands of times per second while accelerating. 

If you put 2 controllers in parallel they are both trying to do this. One turns off but not the other yet (they will never share perfectly equally) and the current in the motor continues to rise through the 1 controller. The current passing through the transistors to the motor at any one time is equal to the current flowing in the motor. When one turns off first the ever increasing current tries to flow through the other controller as the motor current continues to rise. Current limit is defeated because any time the transistors are on in EITHER controller the current continues to rise. The transistors turn back on in the one that turned off first to find the motor current already high, and it continues to climb as the current limit tries to quickly turn it off. Very quickly one or both of the controller suffers a failure in the power section (in the transistors feeding the motor.) It sounds like a gun going off as flames shoot out of the box. 

A controller is a "buck converter" without an inductor. The motor's field winding takes on the role of the inductor. You can get more and better explanations of how they work if you look that term up in google. I bet someone will come along and give a more complete answer than I can too.


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## Yukon_Shane (Jul 15, 2010)

EVfun said:


> There is not electronics prerequisite to asking a question, someone just wasn't being very nice. I am going to attempt a description of what happens as a motor is started from zero rpm.
> 
> The transistors in the controller turn on and current starts flowing into the motor. As long as the transistors are ON the voltage on the motor and the current through the motor continue to rise. At low rpm the motor will pass a huge amount of current at very low voltage so quickly the current rises to the maximum the transistors in the controller can handle. The transistors are turned OFF by the current limit circuit. The current continues flowing in the motor through a set of diodes in the controller (called the freewheel diodes) and the current slowly falls. A tiny fraction of a second later the transistors turn back ON and the current begins rising. The current limit is reached again and the transistors are turned OFF, allowing the current to slowly drop while flowing through the freewheel diodes. This process repeats thousands of times per second while accelerating.
> 
> ...


Well that's a pretty convincing reason to avoid putting two controllers in parrallel.

Thanks for the explanation. I'm always looking to understand these system better so if anyone has a recommendation for reference materials on buck converters I'd appreciate it.


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## ga2500ev (Apr 20, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



Tesseract said:


> Oy. Inductor and transformer design is the deep end of the SMPS pool... I don't think I could explain how to design them in a post even if you paid me. I'll try to give you a couple of pointers but - like pretty much everything else in life - if you really want to learn this you'll have to plow through the material yourself.


Absolutely. I think that's why I've been so frustrated with it. But unlike other common components like resistors, caps, diodes, and switches, it's the one component that you may need to construct yourself.

BTW I've been wading through tons of stuff. I keep asking questions because I'm trying to integrate a ton of different facts into a workable whole.



> The first selection criterion is whether the core of the inductor/transformer is expected to store energy or not. Applications that need the core to store energy are the flyback "transformer", any filter inductor, and the inductor in all of the non-isolated topologies. If the answer is "yes" then you need a core with an air gap. If the core material is ferrite then it needs to literally have a gap cut into it (preferably the center pole, if possible, to contain the fringing flux; I'm guessing that made little sense, and this is just *one* of the bizarro bits about magnetics design!), otherwise, use a material with a "distributed" air gap, such as powdered iron, molypermalloy powder, etc.


So this is the reason that common low frequency power transformer cannot be used in these types of applications. It's not storing energy because both the primary and secondary are energized at the same time.

An explanation of the air gap that made sense is located in this magnetics tutorial I found.



> So, we must see how to increase the amount of energy stored in the core. If we increase the inductance, then the current will drop, and the current carries squared weight! No good idea. It's better to reduce the inductance, so the current increases. Given that the stored energy depends linearly on the inductance, and on the square of the current, it's obvious that as we reduce the inductance, the stored energy increases in proportion.
> 
> How do we do that? We cannot simply reduce the number of turns! This would bring us into the claws of equation 1, and increase the flux density to a level that is far higher than what the ferrite can tolerate! Do you realize the problem? We need to reduce the inductance, while keeping the number of turns in order to preserve flux density!
> 
> There is a very simple tool for doing this: Air! Simply force the magnetic flux to jump over an air gap, by separating the two core halves by a small distance. The effect of this air gap is reducing the effective permeability of the core, thus reducing its AL value, without affecting other parameters.


I understand why there are EI and EE cores now too because each facilitates creating that air gap.

BTW the cut in the center pole makes sense too. Magnetic energy loops in a circuit through the center pole. 




> If you are trying to pick a COTS (commercial off-the-shelf) inductor then look for one that has a DC current rating; a core without an air gap - no matter how big it is - will not be able to tolerate DC at all.
> 
> Note that if you are designing a true transformer then you DO NOT want an air gap; indeed, you want the so-called 'magnetizing inductance' to be as high as possible, so that the no-load current is as low as possible, but I digress once again...


Which again is why a power transformer core is useless in this application.



> The second consideration is one I mentioned before - how many amp-turns (NI) is needed? You probably don't know how many turns are needed, but you should have a fair idea of the current. Know that if you need to design a filter inductor to carry, say, 83A, then a core with an NI rating of 60 ain't gonna cut it!


Every data sheet I see has the Al value. I'm having a tough time find the NI value on them. Might it be called something else?



> The third consideration is the ripple current, or the AC component of the total current, which the inductor must carry. The peak of the ripple must not cause the inductor to saturate (ie - exceed its NI rating). There is no hard-rule for selecting how much ripple to design your inductor for, but it should be apparent that there is no free lunch here - less inductance results in higher peak ripple current at a given switching frequency (more accurately: a given on time). NB - a corollary to NI is Volt-Seconds (or V-microseconds). A given core will be able to support x volts for y time; a larger core will be able to support a higher voltage for the same time, or the same voltage for a longer time.
> 
> The fourth consideration is the amount of inductance which depends on the switching frequency and the peak voltage or current. If you find that a core is too small to support the required Vs or NI, then you can try increasing the frequency. If you find that the frequency is outside of the ranges I previous suggested, then you need to pick a bigger core!


It's complex because a lot goes into it: core material, size, and air gap all affect the energy storage capability of an inductor. 


> On a more practical note, I can almost guarantee you won't find any COTS inductors suitable for 80A+ of current - COTS inductors are made for small SMPS applications like National Semiconductor's "Simple Switcher" series (now part of TI - which is almost heretical to people like me). At this current level you are expected to design your own inductor or transformer.


An honestly since you can't get it COTS, and it's difficult to evaluate a salvaged inductor, one is usually better off selecting a core and winding it for themselves.


> BTW - I've probably missed a few things... like I said in the beginning, I can't possibly explain everything in a forum post!


Any whaps with the clue stick is always helpful. It makes my readings make more sense.



> You can use any core geometry you want for a flyback - some are better suited to a given application than others, of course - but the one constant is that the core will always have a gap (it's not really a transformer, hence my use of quotes above; more like a coupled inductor, as the primary and secondary never conduct at the same time).
> 
> It seems I just explained something you already figured out... oh well, not going to delete it now.
> 
> The flyback is rarely used above 300-400W because of the high peak current and voltage stress it places on the switch and rectifier; that UPS almost certainly used the half-bridge or maybe the two-switch forward instead. At any rate, you can certainly use a multimeter to identify the windings, and then a low AC voltage to determine the transformation ratio of said windings. Don't try to apply more than 1V of 60Hz AC to a high frequency transformer or you might cause it to saturate.


1V. Seems like I'm looking at an op-amp follower with 1/10 gain.



> That will take years, if not decades. I mean, I still learn more subtleties and whatnot about magnetics every time I design them. For example, I just learned from experience why planar transformers aren't nearly as cool as they would appear to be (in short: high leakage inductance).
> 
> BTW - leakage inductance is the uncoupled inductance in a transformer. You measure it by shorting together any one winding then measuring the inductance across any other winding. In a perfect transformer all flux is linked to all windings and there will be no leakage inductance, but transformers are never perfect so there will always be some flux which is not coupled to any other winding; this flux stores energy that zaps the switch or the rectifier when either turns off. So-called "soft switching" or resonant and quasi-resonant topologies attempt to use the leakage inductance to do something useful, but now we are leaving the pool and going straight to the ocean coast with a mean riptide going...


Actually my readings gives some tips on minimizing the leakage:

1) Wind the primary closest to the core.
2) Make sure to completely cover the primary winding with the secondary winding(s). Any exposed primary turns will leak.
3) Always use a closed core. It echos something you said earlier: drums and bar cores will leak all over the place.
4) if multiple secondaries, wire them inside out from the highest power secondary to the lowest. They serve as a sort of magnetic Faraday cage transferring the magflux into energy instead of letting it leak out.

I'm just trying to get the basics down. I'm also getting a clearer understanding of why multiphase flybacks are used for higher wattage applications. To quote this Microchip App Note:



> It is almost impractical to design a single synchronous
> buck converter to deliver more than 35 amps load
> current at a low output voltage. If the load current
> requirement is more than 35-40 amps, more than one
> converter is connected in parallel to deliver the load.


It looks like this can be done in a buck, forward, or flyback configuration. BTW this datasheet looks like a comprehensive discussion of all types of SMPS topologies and their applications.

Thanks for the info as always...

ga2500ev


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## DJBecker (Nov 3, 2010)

There are a gazillion details when selecting an inductor.

One you may not have thought of is physical strength and rigidity.
When you store a lot of energy in an inductor, there will be considerable mechanical pressure. This will cause the inductor to flex, converting some of the energy into heat and sound.

One of the reasons for using a toroid is that it's symmetrical and quite strong, reducing the tendency to "sing". This is enhanced by pre-stressing to increase rigidity.


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## ga2500ev (Apr 20, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*

Here's a really good paper on inductor cores and how to choose them. Complete with design examples.

UPDATE: NI (ampere turns) is computable. Check out this tutorial.

Happy reading..

ga2500ev


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## major (Apr 4, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



ga2500ev said:


> UPDATE: NI (ampere turns) is computable. Check out this tutorial.
> 
> Happy reading..


I don't know about that reference ga  I don't think it is well written and there is an obvious error in the example. They use the toroid mean diameter instead of the magnetic path length to calculate the NI.

And what is the black line in this graph they use?


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## Tesseract (Sep 27, 2008)

*Re: Kostov dual 220V 9" or single Netgain Warp11HV*



ga2500ev said:


> Absolutely. I think that's why I've been so frustrated with it. But unlike other common components like resistors, caps, diodes, and switches, it's the one component that you may need to construct yourself.


Replace "may" with "almost always" and I'll agree with that 



ga2500ev said:


> An explanation of the air gap that made sense is located in this magnetics tutorial I found.


Just an FYI - it is unlikely I am going to check your linked sources for veracity/accuracy, so don't take my silence on their content as an implicit approval of it. The esteemed major apparently found something squirrelly with one of them.



ga2500ev said:


> I understand why there are EI and EE cores now too because each facilitates creating that air gap.


Nah, E cores (and EI) are common because it is possible to make them by stamping sheets of steel without any wasted material. 

(this is for low frequency transformers - at high frequency ferrite is the most commonly used core material)



ga2500ev said:


> Every data sheet I see has the Al value. I'm having a tough time find the NI value on them. Might it be called something else?


The datasheet for a COTS inductor is unlikely to specify NI. It is possible to determine NI through calculation if you know the core's "effective cross sectional area", its saturation flux level and its permeability.


ga2500ev said:


> 1V. Seems like I'm looking at an op-amp follower with 1/10 gain.


No, you are looking at using the secondary of a low voltage transformer with a resistor divider if necessary.

NB - saturating a transformer doesn't hurt it, but it will affect the voltage transformation ratio between windings (since an incremental increase in applied voltage will not result in a proportional increase in flux).



ga2500ev said:


> Actually my readings gives some tips on minimizing the leakage:
> 
> 1) Wind the primary closest to the core.
> 2) Make sure to completely cover the primary winding with the secondary winding(s). Any exposed primary turns will leak.
> ...


#1 and #3 are good tips. #2 is so-so because it ignores proximity effect. #4 is correct, but it's somewhat redundant to #2.



ga2500ev said:


> I'm just trying to get the basics down. I'm also getting a clearer understanding of why multiphase flybacks are used for higher wattage applications. ..


Multiphase _bucks_, you mean. And these are almost exclusively used for supplying the 0.8V to 1.8V demanded by modern CPUs (my desktop has an 8-phase buck to supply 1.2V at up to 100A to the so-called "core" logic - pretty cool stuff).


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## major (Apr 4, 2008)

palmer_md said:


> The website you have linked on your profile page is down. Has been for a while.
> 
> http://roadwarrior.free-man.com/


I know it looks like bjfreeman is gone and I probably should leave well enough alone, but you never can tell when he'll reappear. I was reading another thread and rwaudio responded to a post which included a link by jstraubel. http://www.diyelectriccar.com/forums/showthread.php?p=288218#post288218 While reading that link, I saw the picture of two yellow top Optimas which looked familiar. Sure enough, it is the same photo I saw on bjfreeman's web site just last week. 

I do copy content from web sites and use it and sometimes post some of it here on this board. I always try to give due credit to the source. It would appear that bjfreeman does not think along those same lines.

If bjfreeman does decide to once again post on this board, members should beware 

from: http://roadwarrior.free-man.com/Conversion2000.shtml



Power usage: 

high way driving (45mph) up an 15% grade 325-375KW.
high way driving (60 mph) on the level is 196 KW
city driving on level about 96KW.
Max grade is 15% for 3 hours. 











Max Battery storage is 300V at 200 ah ( 96KW for 1/4 hour)
25 batteries in series at $150.00 each =$3,750.00

from: http://www.jstraubel.com/944EV/EVproject.htm


*The Batteries:*








​Twenty 12V, deep-cycle Optima "yellow-top's" (D750S) for a total system voltage of 240 and a total pack weight of about 850 pounds. Peak power (at 9 kw per battery) ~180 kw.


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## bjfreeman (Dec 7, 2011)

major said:


> I know it looks like bjfreeman is gone and I probably should leave well enough alone, but you never can tell when he'll reappear. I was reading another thread and rwaudio responded to a post which included a link by jstraubel. http://www.diyelectriccar.com/forums/showthread.php?p=288218#post288218 While reading that link, I saw the picture of two yellow top Optimas which looked familiar. Sure enough, it is the same photo I saw on bjfreeman's web site just last week.
> 
> I do copy content from web sites and use it and sometimes post some of it here on this board. I always try to give due credit to the source. It would appear that bjfreeman does not think along those same lines.
> 
> ...


thanks for the link, I thought it was from Metericminds conversion.
I have a note on the first page that I am doing a facelift.
if you noticed I give metricmind credit. so Now i will add this.
I have not finished the face lift to the site. I noticed someone from the forum accessed my site so was able to track down this post.
Have at it major. BTW one of the advertising techniques used by apple and Microsoft was to create a dispute that would be carried in the news for free.


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## Ziggythewiz (May 16, 2010)

Typically one gives credit if one uses an image to illustrate something being done by someone else, not on one's own website to say "Look at my awesome stuff! items pictured or described here may not actually be mine"


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## bjfreeman (Dec 7, 2011)

Ziggythewiz said:


> Typically one gives credit if one uses an image to illustrate something being done by someone else, not on one's own website to say "Look at my awesome stuff! items pictured or described here may not actually be mine"


Up to 2005 I was researching and designing my system.
so I used pictures, from sites I was learning from, that I found to illustrate my discussion of my decision process.
I also mention this if you read far enough.
however for those finding fault I will put this up front. It won't stop those that want to focus on one page that does not mention what they expect.


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## frodus (Apr 12, 2008)

Why don't you have pictures on the side that are of your project?


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## palmer_md (Jul 22, 2011)

bjfreeman said:


> I also mention this if you read far enough.
> however for those finding fault I will put this up front.


Standard practice is to put the source reference for a photograph directly below the photo.

http://www.ehow.com/how_4586049_cite-online-image.html


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## bjfreeman (Dec 7, 2011)

palmer_md said:


> Standard practice is to put the source reference for a photograph directly below the photo.
> 
> http://www.ehow.com/how_4586049_cite-online-image.html


this is my basis.
http://www.copyright.gov/fls/fl102.html


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## bjfreeman (Dec 7, 2011)

frodus said:


> Why don't you have pictures on the side that are of your project?


wait for the next page that is when I started putting in the final version I use now.
first I am working the face list.
next I am working of filling in the years before I actually started. How I got to the things I used.
and as I have said before once I get the bus on a lift I will drop the boxes and take scads of pictures.
I still have more subjects to integrate as well.
The are focused on Fulltimers that have Bus conversions.


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## JRP3 (Mar 7, 2008)

major said:


> I know it looks like bjfreeman is gone and I probably should leave well enough alone, but you never can tell when he'll reappear.


You don't even have to say his name three times


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## bjfreeman (Dec 7, 2011)

JRP3 said:


> You don't even have to say his name three times


It was inaccurate to assume I was "gone" I do have a real life and it has gotten very busy.


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## few2many (Jun 23, 2009)

Hey guys! What did I miss, anything good?


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