# toroid inductor needed between Soliton and dc-dc?



## dtbaker (Jan 5, 2008)

I am gathering parts I'll need for my next build which will use a Soliton Jr... and would like to confirm the differences between this and the typical old-school Curtis controller build...

Using Soliton:

- no need to buy main contactor, its internal
- use hall effect (voltage) throttle rather than old standby pb-6 potbox
- finned heat sink on bottom not too effective, better to use built-in fluid cooling by adding pump and external radiator if extended highway use or high-current is anticipated.

not sure about a few threads I read regarding issues damaging dc-dc convertors, which required the addition of 'toroid inductor' on the input side to protect the dc-dc. could someone please clarify/confirm whether this is something that needs to be considered?


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## Tesseract (Sep 27, 2008)

dtbaker said:


> ...
> - no need to buy main contactor, its internal
> - use hall effect (voltage) throttle rather than old standby pb-6 potbox
> - finned heat sink on bottom not too effective, better to use built-in fluid cooling by adding pump and external radiator if extended highway use or high-current is anticipated....


The issue of the inductor is covered in a FAQ on our support page because hardly a week goes by without someone asking about that.

You can use a Hall effect throttle, or the original TPS or pedal sender, or a potentiometer type throttle (like ours) but do not use a PB-6. Not only is the pot inside wired up wrong, it's also crappy.

Adding a heatsink to the bottom of any of our controllers will do absolutely nothing besides deprive you of a convenient means of mounting the controller.


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## dtbaker (Jan 5, 2008)

Tesseract said:


> The issue of the inductor is covered in a FAQ on our support page because hardly a week goes by without someone asking about that.


...ok, so just to pull the answer into this thread 
'The popular NetGain WarP-9 has approximately 100uH of inductance even at 500A, hence there is quite a margin between it and the lower limit for our controllers.'
Seems to conclude that with a Warp 9, and probably with ADC motors, there is no need for an additional inductor. If I have that wrong, let me know!







Tesseract said:


> You can use a Hall effect throttle, or the original TPS or pedal sender, or a potentiometer type throttle (like ours) but do not use a PB-6. Not only is the pot inside wired up wrong, it's also crappy.


might be crappy, but there's a lot of them out there that have lasted for years.... I just wanted to clarify in that it is probably worth spending the extra $50 on a Hall Effect throttle to work best with a Soliton.




Tesseract said:


> Adding a heatsink to the bottom of any of our controllers will do absolutely nothing besides deprive you of a convenient means of mounting the controller.


a function of where the 'hot' components are, the fluid cooling channels and top fins w/ fans I assume. Additional consideration is that even though the bottom may not add a lot of convective cooling, even with a finned heatsink, it *probably* is still not a good idea to mount any controller directly above a motor where all the hot air rises... much better to channel some fresh air moving over the controller, and consider fluid cooling for demanding applications.


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## Tesseract (Sep 27, 2008)

dtbaker said:


> ...ok, so just to pull the answer into this thread
> 'The popular NetGain WarP-9 has approximately 100uH of inductance even at 500A, hence there is quite a margin between it and the lower limit for our controllers.'
> Seems to conclude that with a Warp 9, and probably with ADC motors, there is no need for an additional inductor. If I have that wrong, let me know!


Err... Wrong FAQ. That entry concerns the minimum inductance the motor must have for the controller to work properly. The one you want talks specifically about inductors and dc/dc converters (Troubleshooting #4):

_...A toroidal inductor is preferred, but a rod or drum type can be used, too, as long as it is at least 100uH and rated for between 1.5x and 2x the current required by the converter. Examples of suitable part numbers are Vishay/Dale IH10BQ101K, Bourns 2312-H-RC or 2312-V-RC, etc.
_​


dtbaker said:


> [The PB-6] might be crappy, but there's a lot of them out there that have lasted for years.... I just wanted to clarify in that it is probably worth spending the extra $50 on a Hall Effect throttle to work best with a Soliton.


Well, if you already have a working PB-6 and want to try it out, then sure, who am I to dissuade you? You will need to either rewire the pot as a pot, rather than as a variable resistor, or add a pullup resistor from S5V to THROT on the controller.

Otherwise, we recommend using an automotive TPS - such as is used in our throttle assembly - as a throttle transducers, and not a Hall effect tranducer since they can be affected by stray magnetic fields unless they are properly shielded.



dtbaker said:


> ... it *probably* is still not a good idea to mount any controller directly above a motor where all the hot air rises... much better to channel some fresh air moving over the controller, and consider fluid cooling for demanding applications.


My official position is that liquid cooling be used in all applications, but particularly when motor current is set to 50% of the maximum allowed or higher (ie - 300A on a Soliton Jr; 500A on a Soliton 1). 

Otherwise, your suppositions that heat from the motor can affect the controller if they are mounted close to each other and that the liquid cooling ports are placed in the vicinity of the highest heat flux from the IGBT modules are both correct.


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## dtbaker (Jan 5, 2008)

Tesseract said:


> (Troubleshooting #4):
> _...A toroidal inductor is preferred, but a rod or drum type can be used, too, as long as it is at least 100uH and rated for between 1.5x and 2x the current required by the converter. Examples of suitable part numbers are Vishay/Dale IH10BQ101K, Bourns 2312-H-RC or 2312-V-RC, etc.
> _​



I guess I mixed FAQs, but am now confused again as to whether I need to add an inductor, or not. If the Warp9 motor supplies about 100uH, is that enough in the system, or not? I don't feel qualified to understand the whys, I just want a simple yes or no as to whether I should add one and where to get it. 


The second issue is that I have not seen these in the parts lists of my favorite evnetics dealers. seems like it would be a good thing for them to be sure to offer the complete 'kit' or add-ons recommended for Solitons: cooling system and throttles in addition to the controllers themselves.


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## Tesseract (Sep 27, 2008)

dtbaker said:


> I guess I mixed FAQs, but am now confused again as to whether I need to add an inductor, or not. If the Warp9 motor supplies about 100uH, is that enough in the system, or not? I don't feel qualified to understand the whys, I just want a simple yes or no as to whether I should add one and where to get it.


Yes, you need the inductor for the dc/dc converter. And possibly for the charger, too. You can get a large inductor that handles both at the same time (charger output and dc/dc converter input, just to be extra clear) from Rebirth Auto. You can buy individual inductors from DigiKey, Mouser, etc... I provided part numbers in the previous post.

Once again, the motor inductance has no bearing on the need for an inductor feeding the dc/dc converter.




dtbaker said:


> The second issue is that I have not seen these in the parts lists of my favorite evnetics dealers. seems like it would be a good thing for them to be sure to offer the complete 'kit' or add-ons recommended for Solitons: cooling system and throttles in addition to the controllers themselves.


We do offer a throttle. As for the cooling system, I agree that our dealers ought to supply a kit. I'll keep trying to force them to do just that...


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## major (Apr 4, 2008)

dtbaker said:


> I guess I mixed FAQs, but am now confused again as to whether I need to add an inductor, or not. If the Warp9 motor supplies about 100uH, is that enough in the system, or not? I don't feel qualified to understand the whys, I just want a simple yes or no as to whether I should add one and where to get it.


Hi dt,

The dc/dc is on a branch circuit from the battery and not in the main controller to motor circuit. So the motor inductance is not a factor. What you need is an inductor between the battery and dc/dc. That is what is recommended as I understand it.

major


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## skooler (Mar 26, 2011)

Hi Dan,

I'm sure you have read the thread that I posted a month or so back?

http://www.diyelectriccar.com/forums/showthread.php?t=75037

Using the Soliton Jr and the 400w Chennic DCDC with a 144v, 125AH lead acid pack I was blowing the fuse every time I accelerated past turtle speed.

My advice would be to just do it. It only costs a couple of $$$ and is easy to fit.

Mine is the size of a bottletop and is araldyted to the top of the DCDC. It connects to the positive input side of the DCDC and the traction battery.

Hope this helps,

Cheers,

Mike


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## dtbaker (Jan 5, 2008)

major said:


> Hi dt,
> 
> The dc/dc is on a branch circuit from the battery and not in the main controller to motor circuit. So the motor inductance is not a factor. What you need is an inductor between the battery and dc/dc. That is what is recommended as I understand it.
> 
> major



I just wish it was more clear when I was ordering parts and the controller the first time thru.... 'do this' and make sure that retailers have it in the list of suggested externals for the Soliton. no main contactor required, inductor apparently highly recommended.


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## Tesseract (Sep 27, 2008)

dtbaker said:


> I just wish it was more clear when I was ordering parts and the controller the first time thru.... 'do this' and make sure that retailers have it in the list of suggested externals for the Soliton. no main contactor required, inductor apparently highly recommended.


So... you are upset because whomever you bought your controller from didn't also make it clear that you might need an inductor to protect your dc/dc converter and/or charger? Should I specify an exact part number for an inductor in the Soliton owner's manual, since I can't *force* any retailer to carry any potentially useful accessories?


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## dtbaker (Jan 5, 2008)

Tesseract said:


> So... you are upset because whomever you bought your controller from didn't also make it clear that you might need an inductor to protect your dc/dc converter and/or charger? Should I specify an exact part number for an inductor in the Soliton owner's manual, since I can't *force* any retailer to carry any potentially useful accessories?


well, that would certainly be a pro-active step to address an educational issue that seems to come up with regularity. I dunno whether retailers are failing to understand the issue, or average end users like me just don't really want to know the whys, we just want a shopping list that works for one-stop shopping to minimize shipping fees and after the fact surprises.

Hell, I don't really know or want to know what an inductor is, I just want to know exactly what to get and where to get it if I need it to use with my shiny new Soliton.


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## EVfun (Mar 14, 2010)

Tesseract said:


> So... you are upset because whomever you bought your controller from didn't also make it clear that you might need an inductor to protect your dc/dc converter and/or charger? Should I specify an exact part number for an inductor in the Soliton owner's manual, since I can't *force* any retailer to carry any potentially useful accessories?


It may not be fair, but the Evnetics crew did create part of this. Needing an inductor for other things on the DC bus used to be common -- the old SCR howlers didn't have significant input capacitance. Then the Curtis 1221 came out and it didn't impose much ripple on the input because it was loaded with (kinda) low ESR electrolytic input capacitance. The Auburn Scientific, DC Power Systems, and Cafe Electric controllers followed the Curtis lead and installed significant low ESR input capacitance, so they didn't require an inductor. Your controller jumps back to what was the standard, but there are a lot of newer EVers that don't realize that. The message will have to be shouted out.


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## dtbaker (Jan 5, 2008)

uh, yeah, shouting now....
really don't need to feel like an idiot. I'd much rather feel guided and supporting in learning how to use a *better* controller. I didn't have to worry about inductor w/ old school curtis, but now apparently do w/ Soliton. All I am saying is this is an item that needs to appear in the default schematic/shopping list.


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## skooler (Mar 26, 2011)

Stick one or two of these on the input to your dcdc and the the problem will go away 


http://www.ebay.com/itm/10pcs-Toroi...080?pt=LH_DefaultDomain_0&hash=item2572ccf2d0

I'm assuming your dcdc won't be larger than 400w?


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## dtbaker (Jan 5, 2008)

skooler said:


> Stick one or two of these on the input to your dcdc and the the problem will go away
> 
> 
> http://www.ebay.com/itm/10pcs-Toroi...080?pt=LH_DefaultDomain_0&hash=item2572ccf2d0
> ...



the chennic I have in my Swift is 400 watts, but am considering the ACME dc-dc (from EVolveElectrics.com) for the build that will have the Soliton. Its rated to output up to 53 amps at 13.8v and is just $218. so... thats closer to 700 watt max I guess. That build will have 156v nominal input, so max current in will be around 4.5 to 5 amps, right? so the inductors you linked to should work (rated at 5amps)

Another simple question.... do you just wire one in-line on both the + and - input lines, or only on +?

The Chennic has been 'ok', and was cheap at $99, but seems very sensitive to a narrow nominal voltage band. The first one only lasted a year.

If this is all it takes, I'd suggest to EVnetics that they include 2 with every controller sold, and include them in the suggested schematic and installation instructions. Seems like it would be a very inexpensive way to prevent lots of support questions and surprise failures of dc-dc units.


followup questions I have are:

- would it be BETTER to put 2x (100uH each) on each input wire (+/-) to the dc-dc? in series or parallel?

- would it be a good idea to add inductors to a build that has a Zilla controller, or is Soliton the only one requiring these to protect the dc-dc units?


Dan


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## skooler (Mar 26, 2011)

dtbaker said:


> the chennic I have in my Swift is 400 watts, but am considering the ACME dc-dc (from EVolveElectrics.com) for the build that will have the Soliton. Its rated to output up to 53 amps at 13.8v and is just $218. so... thats closer to 700 watt max I guess. That build will have 156v nominal input, so max current in will be around 4.5 to 5 amps, right? so the inductors you linked to should work (rated at 5amps)
> 
> Another simple question.... do you just wire one in-line on both the + and - input lines, or only on +?
> 
> ...


the ones I linked to should be fine with the Larger dcdc.

I only wired mine on the positive side. Between the dcdc input and the positive battery terminal.

I don't know if protecting the negative side will help.

More inductance can only be a good thing in reducing ripple.

Considering the price and ease of implementation. I'd install one regardless of what controller is used.


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## Tesseract (Sep 27, 2008)

Modifying the installation schematic to show the inductor needed to protect some dc/dc converters is a reasonable request (and besides, the schematic is long overdue for an update, anyway), but I'm not really inclined to include free parts with every controller that might not even be necessary. After all, a sizable proportion of EVs use the tailshaft on the motor to drive the original alternator (as well as the a/c compressor and even the power steering pump) and those conversions wouldn't need the inductor, except, perhaps, for the charger, and then the inductor would almost certainly have to be a lot larger (e.g. - 1kW would be a huge power level for a dc/dc converter, but tiny to the point of useless for a charger).


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## skooler (Mar 26, 2011)

Tesseract said:


> Modifying the installation schematic to show the inductor needed to protect some dc/dc converters is a reasonable request (and besides, the schematic is long overdue for an update, anyway), but I'm not really inclined to include free parts with every controller that might not even be necessary. After all, a sizable proportion of EVs use the tailshaft on the motor to drive the original alternator (as well as the a/c compressor and even the power steering pump) and those conversions wouldn't need the inductor, except, perhaps, for the charger, and then the inductor would almost certainly have to be a lot larger (e.g. - 1kW would be a huge power level for a dc/dc converter, but tiny to the point of useless for a charger).


Sorry to go off topic...

Would it not just make more sense to put a contactor on the charge side rather than a inductor and separate it completely?

In other words, when the controller is on, the chargers contactor on the DC side closes?

EDIT: I mean contactor is open when the controller is on, not closed.


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## Woodsmith (Jun 5, 2008)

I suppose it is down to a balance.

Do you write a manual for your controller and how to connect it in its usual application, or do you write a manual on how to build an EV around your controller?


TBH, I wouldn't know if an inductor was needed or not and so wouldn't necessarily know to ask in the first place.
I would hope information on how to build an EV would provide that but perhaps not necessarily a component manufacturer unless they were being specifically helpful in providing 'typical layout' schematic as pointers.


The Curtis diagrams include contactors, switches and resistors but doesn't specify in any more detail as it is down to the installer to determine the appropriate components depending on application.


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## dtbaker (Jan 5, 2008)

Tesseract said:


> Modifying the installation schematic to show the inductor needed to protect some dc/dc converters is a reasonable request


it would be a big help for the 'paint by numbers' guys like me who are a lot more mechanical than electrical. 




Tesseract said:


> After all, a sizable proportion of EVs use the tailshaft on the motor to drive the original alternator (as well as the a/c compressor and even the power steering pump)


none of the in-town conversions I know of locally, or would plan, would include A/C or belt driven anything... A/C is really not needed for the typical short trip where I happen to live, and I'd hate to divert that much energy if not needed... so far there are no 'large' vehicles local with power steering, and I would guess people would be more likely to go with electric pump anyway since it can run when vehicle is at low speed when the power assist is needed where a pulley driven pump really cant.



Tesseract said:


> ...and those conversions wouldn't need the inductor,


this is where you lose me.... I don't have a clue how to evaluate whether an inductor is 'needed' or not in any specific case. I can understand (now) that if the guts of the Solitons basically send ripples back thru the traction pack, that its a good idea to smooth that out for the dc-dc. I don't get how or when it would be required for the charger since the controller isn't 'running' while charging?


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## skooler (Mar 26, 2011)

dtbaker said:


> I don't get how or when it would be required for the charger since the controller isn't 'running' while charging?


No but the charger is still connected while the controller is running


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## Tesseract (Sep 27, 2008)

skooler said:


> ...Would it not just make more sense to put a contactor on the charge side rather than a inductor and separate it completely?


Sure, but whether it makes more sense to use a contactor or an inductor depends on the relative cost of each... Generally speaking, an inductor will be less expensive than a contactor, and, of course, has no moving parts. 




Woodsmith said:


> ...Do you write a manual for your controller and how to connect it in its usual application, or do you write a manual on how to build an EV around your controller?


The former - that is, the Soliton Owner's Manual only addresses the installation and operation of our controllers, not the general process of converting a vehicle. There are numerous books on the latter subject, and though I confess they are somewhat wanting and/or dated in many respects, I don't really have a desire to write such a book myself, and I certainly won't put that kind of effort into a manual that a good half our customers never bother to read in the first place...


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## dtbaker (Jan 5, 2008)

skooler said:


> No but the charger is still connected while the controller is running


but how would the ripples affect the charger if it isn't 'running'? I was sort of assuming that chargers have some diodes or other stuff to prevent juice from flowing backward? (crude mechanical analogy)


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## skooler (Mar 26, 2011)

Tesseract said:


> Sure, but whether it makes more sense to use a contactor or an inductor depends on the relative cost of each... Generally speaking, an inductor will be less expensive than a contactor, and, of course, has no moving parts.


Understood on the moving parts side of things.

Say I was using the EMW charger at 10KW. That would mean I'd need a 10KW inductor (or say 100amp).

Are inductors in that size affordable? I cant find anything big enough!



> but how would the ripples affect the charger if it isn't 'running'? I was sort of assuming that chargers have some diodes or other stuff to prevent juice from flowing backward? (crude mechanical analogy)


I don't know the inner workings of a charger but I suspect there is some kind of capacitance on the output side which suffers from the same problems as the input of the dcdc converter.

Don't know about diodes, you would assume so but they don't install them on the dcdc converters.

Cheers,

Mike


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## dladd (Jun 1, 2011)

dtbaker said:


> - would it be a good idea to add inductors to a build that has a Zilla controller, or is Soliton the only one requiring these to protect the dc-dc units?
> 
> 
> Dan


my understanding is that it's because of the film capacitors used in the Soliton vs. the electrolytic capacitors used in other controllers. The film has some upsides (smaller, longer life, probably some other things?), but the downside is the higher ripple. I'm not aware of any other controllers that use these.


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## Yukon_Shane (Jul 15, 2010)

I think this discussion is very interesting and all the points raised are certain fair but I think folks may be missing one small point and that is that the DC/DC converters we are currently using in our EV's are very poorly (or not at all) designed for this purpose.

Evnetics makes a recommendation as to how to protect the most common DC/DC converters because they know that they are poorly made and, to my thinking, this is above and beyond the call of duty.

I've taken Tesseracts suggested and include an inductor in my DC/DC installation but the fact is I know it's still just a matter of time before this product fails as a result of either current/voltage conditions outside of it's design capabilities or (more likely) dust, dirt and water penetrating it's casing (this product was clearly not designed to be used under the hood of a car).

I for one am very much looking forward to someone (hint hint) developing a proper DC/DC for the diy EV community.


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## dtbaker (Jan 5, 2008)

Yukon_Shane said:


> Evnetics makes a recommendation as to how to protect the most common DC/DC converters because they know that they are poorly made and, to my thinking, this is above and beyond the call of duty.



I don't think its above the call of duty to make sure that the average consumer knows that the Soliton product has different 'guts' with many upsides, AND recommends the addition of a inductor to protect the average dc-dc. 

This is a 'change' from what many of us have gotten used to as the de facto standard old school schematic with the venerable Curtis and the like, brought about by the design of the Soliton. I just think it would cut down on a lot of confusion if this information is plain and obvious as the Soliton being different (in a good way) by having the main contactor included internally.

....a couple of my questions still haven't been answered. 
- if one 100uH inductor is good, would 2x be better or just a waste?
- if 2x is better, should they be in series, or parallel
- should inductors be inserted on both the + and - input to dc-dc, or just the +?


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## Tesseract (Sep 27, 2008)

dtbaker said:


> I don't think its above the call of duty to make sure that the average consumer knows that the Soliton product has different 'guts' with many upsides, AND recommends the addition of a inductor to protect the average dc-dc.


Well that's just it... I recommended using an inductor to protect the dc/dc converter on p7 of the Soliton Owner's manual, in a FAQ on our website, and in numerous threads on here, including one you posted to.

And just in case I have not made my position on this crystal clear, the quality of the design and the components used in another product that might be used with our controllers is not my responsibility. It is therefore unreasonable to expect me to solve the engineering shortcomings of such products. If I do provide a solution - such as the recommendation to use an inductor to protect the dc/dc converter from ripple - then please don't make me regret doing so by hammering on me for days - literally days, now - about how I could have explained it more prominently or simply or often or whatever. All this will do is make me less inclined to provide help in the future.



dtbaker said:


> ....a couple of my questions still haven't been answered.
> - if one 100uH inductor is good, would 2x be better or just a waste?
> - if 2x is better, should they be in series, or parallel
> - should inductors be inserted on both the + and - input to dc-dc, or just the +?


1. Two inductors will reduce the ripple proportionally, but whether that is of any benefit or a waste depends on the type of inductor and the internal components of the device to be protected. In short, this can't be answered.
2. Two inductors will have double the inductance at the same current rating if wired in series, and will have half the inductance at double the current rating if wired in parallel, assuming there is little or no coupling between them (if they are toroidal core inductors then that is a safe assumption; if a coil of wire then not).
3. Technically speaking, it does not matter if you put the inductor(s) in series with the + or - terminal, but the convention is to put them in series with the + terminal.


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## dtbaker (Jan 5, 2008)

Tesseract said:


> 1. Two inductors will reduce the ripple proportionally, but whether that is of any benefit or a waste depends on the type of inductor and the internal components of the device to be protected. In short, this can't be answered.
> 2. Two inductors will have double the inductance at the same current rating if wired in series, and will have half the inductance at double the current rating if wired in parallel, assuming there is little or no coupling between them (if they are toroidal core inductors then that is a safe assumption; if a coil of wire then not).
> 3. Technically speaking, it does not matter if you put the inductor(s) in series with the + or - terminal, but the convention is to put them in series with the + terminal.


thanks!
Not trying to hammer on you, just trying to boil down whats needed and how to do it for all the ignorant new customers, like me...


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## ElectriCar (Jun 15, 2008)

Build your own inductor with the wire size you need. Here's a calculator. I just figured out that for a given number of turns, a larger diameter makes more inductance. I've built one before to get the whine out of an amplifier in my car back in the 80's but had no clue of the size, just wrapped #12 wire about 80 times around a 5/8 diameter steel rod about 10 inches long.


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## TTmartin (Feb 7, 2012)

Out of curiousity I just removed the cover on the dc converter I aquired, its a Meanwell sp750-12.
would anyone be able to confirm or not, that the photo below of the input side of this dc-dc shows 2off toroidal inductors fitted on the input side of this unit, meaning an auxcillery inductor is not required.
unfortunatly I dont really know what I'm looking at, so any advice is greatly appreciated. the second photo is the 12volt output side.


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## ElectriCar (Jun 15, 2008)

Can't tell by a photo. You have to verify that they're connected in series with the input wiring. I built one with a piece of 1.25" PVC conduit wrapped 24 times with #14 wire. Calculates out to 12.5uh or so. 

Think I need one on my Cycle Analyst as it now jumps as if I pushed the button. I think it's responding to the noise.


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## Tesseract (Sep 27, 2008)

TTmartin said:


> Out of curiousity I just removed the cover on the dc converter I aquired, its a Meanwell sp750-12.
> would anyone be able to confirm or not, that the photo below of the input side of this dc-dc shows 2off toroidal inductors fitted on the input side of this unit, meaning an auxcillery inductor is not required....


No, those inductors are being used as what are called "common mode chokes". These are for reducing electrical noise emissions and will do absolutely nothing to block ripple. More specifically, they cancel out current that is of equal magnitude on on both of the input lines (ie - common mode current), while letting through the current that the supply draws during operation. Unfortunately, the latter would include ripple from the controller.

Pretty much any power supply intended for operation from the AC mains will need a series inductor.


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## JRP3 (Mar 7, 2008)

Tesseract said:


> You can get a large inductor that handles both at the same time (charger output and dc/dc converter input, just to be extra clear) from Rebirth Auto.


I can't find it on the website, is it a special request item or something?


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## dtbaker (Jan 5, 2008)

a local EVer has been telling me that it may be more effective to use a diode instead of an inductor to completely stop the ripple from getting back into the dc-dc, and another on the charger.

he's suggesting VS-1N3891R .(12 amp, 200 volt). The "R" on the end of the part no. means that the cathode is insulated from the case which is the anode (+ voltage input) If you want it the other way around, leave the "R" off the part no. You can order this diode from Newark.com (Element 14, an electroic component distributor). Also you can see the spec there also.

what do all you EE types think of this?


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## TTmartin (Feb 7, 2012)

Tesseract said:


> No, those inductors are being used as what are called "common mode chokes". These are for reducing electrical noise emissions and will do absolutely nothing to block ripple. More specifically, they cancel out current that is of equal magnitude on on both of the input lines (ie - common mode current), while letting through the current that the supply draws during operation. Unfortunately, the latter would include ripple from the controller.
> 
> Pretty much any power supply intended for operation from the AC mains will need a series inductor.


That's very clear thanks.

So would I be correct in saying the spec below would be the sort of inductor I require as the input side of this unit is stated as 11amp

Part Number:	CTX100-10-52LPR 
Manufacturer:	Coiltronics/Div of Cooper/Bussmann
Series:	-
Short Description:	INDUCTOR TOROID PWR 100UH 17.6A


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## ElectriCar (Jun 15, 2008)

I'm now wondering if IGBT's create more noise/ac ripple than mosfets do.


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## JRP3 (Mar 7, 2008)

dtbaker said:


> what do all you EE types think of this?


In one of the many threads discussing this topic Tesseract has explained why a diode is not the correct solution, the inductor is. It should cost about $5 and fix the problem. Buy this: http://www.mouser.com/Search/ProductDetail.aspx?R=2312-V-RCvirtualkey54200000virtualkey542-2312-V-RC


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## dtbaker (Jan 5, 2008)

JRP3 said:


> In one of the many threads discussing this topic Tesseract has explained why a diode is not the correct solution, the inductor is. It should cost about $5 and fix the problem. Buy this: http://www.mouser.com/Search/ProductDetail.aspx?R=2312-V-RCvirtualkey54200000virtualkey542-2312-V-RC



huh, fascinating.... I will go looking and hope the advanced search can find the response. I'd like to read it, but this inductor versus diode stuff is way out of my league. I just want to do the 'best' thing.

I ordered some 100uH, 5A toroid inductor coils off ebay. they were only a buck apiece, but being 5A I was going to wire a pair in parallel to be safe. my dc-dc is rated at 650 watts, and pack voltage will be nominal 156v, so max current should be less than 5A anyway.

....poked around and read threads for about 1/2 hour without finding an explanation why inductors would be better than diode. also, don't really have any idea whether 100uH is better or worse than putting in two in series for 200uH? I dunno if this is a case where the uH needs to be matched to something, or if 'more is better'.


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## JRP3 (Mar 7, 2008)

I think it had something to do with a diode not smoothing out the peaks the way an inductor would. Frankly for those of us who don't understand the details if Tesseract says a 100uH 5-7amp inductor works why waste time looking for alternatives? It's a cheap, simple solution.


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## Tesseract (Sep 27, 2008)

JRP3 said:


> I can't find it on the website, is it a special request item or something?


 Yeah, the Rebirth Auto inductor isn't listed on the website. It's a huge 100uH/30A beast meant for protecting chargers that are hardwired to the traction pack. Cheaper than a contactor - usually - and nothing to wear out, but a lot more expensive than the little 5-7A jobbers from Digikey, Mouser, etc...



TTmartin said:


> So would I be correct in saying the spec below would be the sort of inductor I require as the input side of this unit is stated as 11amp
> 
> Part Number: CTX100-10-52LPR


That part is marginal if the DC current drawn by the MeanWell is truly 11A, but it shouldn't draw more than 7-7.5A at 750W output (unless your pack will sag down below 125V or so). 



ElectriCar said:


> I'm now wondering if IGBT's create more noise/ac ripple than mosfets do.


 They don't. IGBTs tend to be used in much more powerful controllers than MOSFETs, however, and that can result in more noise. 




dtbaker said:


> ....poked around and read threads for about 1/2 hour without finding an explanation why inductors would be better than diode. also, don't really have any idea whether 100uH is better or worse than putting in two in series for 200uH? I dunno if this is a case where the uH needs to be matched to something, or if 'more is better'.


On the first page of this thread are two posts - one by Skooler and one by EVfun - with links to two threads where I explain about the inductor and the diode, respectively.

Reading those threads should also answer your second question as well. That said, I gave you a specific component recommendation - why are you not satisfied with that?

EDIT: the thread by skooler on the first page has a link to another thread and in that thread is a post by EVfun with a link to another thread.


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## JRP3 (Mar 7, 2008)

Here, I did the work 
http://www.diyelectriccar.com/forums/showthread.php?p=262898&highlight=inductor#post262898

http://www.diyelectriccar.com/forums/showpost.php?p=286892&postcount=187


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