# Cheapest DC-DC converters. 650w for $100 you say?



## lazzer408 (May 18, 2008)

*Cheapest DC-DC converters. 250w $50, 450w $65, 650w $100 you say?*

Ok guys. Check this out. I've been playing with a 250w Thermal Take Power Express power supply. What this thing is, is an add-on power supply for a PC computer that fit in a 5.25" CDrom bay and provides 250w @ 12v regulated to power SLI or Crossfire graphics cards. 2 cards. A slot cover plate mounts in the computer to provide a 120v ac-in jack for a boom-box type power cable. This supply is normally activated when the main PSU turns on but if you don't connect the interface cable to the computer psu's atx connector, then it will always be on. It will power up with DC right to the ac input but it's better if you have the ability to open it and put your pack voltage straight to the main filter cap -after- the line rectifier. I've ran HID headlights as low as 48v input on the cap. Normally this cap sees about 150v. That makes 48-150dc input and 12v out but I would de-rate the output with voltages below 100v.

It's also fan cooled and ISOLATED and I've just discovered they make a 450w and 650 watt version!!! 

Typical internet prices:

250w (rated 21a max) ~$50
http://www.thermaltake.com/product/Power/PurePower/w0130/w0130.asp


450w (rated 30a max) ~$65
http://www.thermaltake.com/product/Power/ToughPower/w0157/w0157.asp

650w rated 30a max?) ~100 <---- 30a? It's twice as big as the 250 and 450 and takes up 2 bays.
http://www.thermaltake.com/product/Power/ToughPower/w0158/w0158.asp


This should make you guys *very* happy! 

http://www.amazon.com/s/ref=nb_ss_g...=aps&field-keywords=thermaltake+power+express


----------



## lazzer408 (May 18, 2008)

I'm tracking down the feedback to try and get 13.8 out of it.  This is on the 250w version I have. If anyone would care to donate one of the larger ones I'll figure it out as well and make a nice walkthru for you.


----------



## JRK5150 (May 18, 2008)

Wow! Would this actually work as a DC-DC converter? I was planning to run an alternator off the front of my motor, but this would be more efficient and nearly as cheap! If this works, lazzer408, you are the MAN!


----------



## KiwiEV (Jul 26, 2007)

This is good news! Well done on your findings mate! This could save us all a bundle!


----------



## lazzer408 (May 18, 2008)

For my motorcycle, I use it at 12v without any problem. Why do autos still retain a 12v battery? There's no engine to start with it. Why not put the dc-dc on a switch and power it up first?

fwiw the HID heallight ballasts are regulating. It will attempt to draw 55w (or 35w depending on the kit) reguardless of the voltage. LED tail/stop/turn bulbs would be as bright at 12 as 13.8. You wouldn't notice much. But I'll continue to track this down for you guys.

Here's the inside of the Thermaltake 250w. Pardon my mess.


----------



## Twilly (Jan 22, 2008)

There is a bunch for sale on E-bay right now, Just got mine...


----------



## John (Sep 11, 2007)

lazzer408 said:


> Why do autos still retain a 12v battery? There's no engine to start with it. Why not put the dc-dc on a switch and power it up first?


In a word redundancy. If your DC/DC converter goes belly up you're not going to suddenly go dark. You're lights will still work your vacuum pump will still work and your car will still run.


----------



## lazzer408 (May 18, 2008)

John said:


> In a word redundancy. If your DC/DC converter goes belly up you're not going to suddenly go dark. You're lights will still work your vacuum pump will still work and your car will still run.


I was thinking that's a good reason to keep the battery. Which is why I'll continue work on the voltage adjustment mods. 

What would you guys like the voltage to be? 13.8? 14.2? Let me know that and I'll have this down to "Replace Rx with a x.xk resistor for xx.x volts"


----------



## Twilly (Jan 22, 2008)

Doesn't an alternator charge at 14.4V?


----------



## lazzer408 (May 18, 2008)

Twilly said:


> Doesn't an alternator charge at 14.4V?


About. But that might not be an ideal float voltage. Depends on the battery I guess.


----------



## JRK5150 (May 18, 2008)

Wouldn't the ideal voltage be about 13.9?


----------



## lazzer408 (May 18, 2008)

JRK5150 said:


> Wouldn't the ideal voltage be about 13.9?


Could be. I figured 13.8v because that's what alot of these ham radio etc power supplies are providing. Reguardless. First thing I have to do is find out HOW to adjust it. The sky's the limit once that's figured out. You guys can then adjust these things to whatever you want. =)


----------



## JRK5150 (May 18, 2008)

Hey, if it's easier to do 13.8 vs 13.9 go for it! I don't think anyone could honestly tell the difference without a meter. I just said 13.9 because I think that's the ideal, but I could be wrong. I'm just stoked you found these and shared! There will be one in my ride here soon!


----------



## lazzer408 (May 18, 2008)

Sometimes I regret not making a profit by buying a bunch and sticking my own label on it and selling them to you guys as dc-dc convertors. I feel that way every time I look in my wallet and look up to see my 1/2 built projects everywhere. But on the other hand, I get that warm fuzzy feeling knowing I may have just helped a whole bunch of EV'ers world wide who are trying to save every penny on their own builds. The needs of the many outweigh the needs of the few, or the one. =)

So, if your not helping the comunity what are you doing? I won't be a part of the profit-hungry-price-gouging-customer-raping companies charging 100s of dollars for a simple convertor that's only 50 bucks just because this one is used in another application. They think their the only ones on the planet selling these? See how they stick it to the EV comunity? They just don't want this to be affordable !!

/rant


----------



## lazzer408 (May 18, 2008)

Lexus said:


> I was reading somewhere ... that the Zilla Controller cost $300 to make ...


I wouldn't doubt it for a second. My argument is more along the lines of "acceptable profit to make a living" vs. "enough profit to fill my 10 garages with exotic cars that I'll never drive while the rest of the world suffers"

I can't wait for China to jump on the controller boat. It sadens me to say that. I wish I could count on an American company to offer me a good product at a good price. :Laughs at the though:

On the Power Express...

It uses a CM6800 Power factor correcting PWM IC. http://pdf.chinaicmart.com/CM6/CM6800.pdf I'm still tracking down the feedback loop. If it's as easy as v-in on pin 15 "Vfb" (voltage feedback) this could be easier then I though. On the other hand it's opto-isolated so there's that circuit to map out to figure out how the output gets back to that pin. I may just try pulling pin-15 lower with a resistor to ground. It's only 1.8v more volts I'm after. The other chip is an LM339 quad comparator. I know for a fact 2 of the comparators are used to drive each of the 2 status LEDs that light when there's a load on either of the "2" outputs. It's really only one 12v rail with 2 shunts to 2 outputs. Just for LEDs? Seems excessive. The other 2 comparators I'm not sure of. One of them might be for the power-on signal handling from the computer's ATX PSU. :shrugs: I should have this figured out by tonight. Dinner time!


----------



## lazzer408 (May 18, 2008)

14.2v close enough?

This is one method of modding a thermaltake power express 250. Solder a 27k ohm resistor across the smt resistor as shown for 14.2v output. 33k will get you 13.7v output (#1). This lowers the voltage on the tx side of the opto isolator. It now takes a higher voltage to produce the signal it's expecting. 14.2v to be exact. This converter has over voltage protection. I'm not sure how far it can be pushed before shutdown. It is also power factor correcting. *Please note that you SHOULD NOT apply your pack voltage to the main capasitor!!!* To connect your pack voltage, unsolder the bridge rectifier and make your connections to the + and - terminals (#2). Anything between the rectifier and the ac input can be removed if you like. When in operation there could be 400v on the large main cap. This is due to the boost converter used for pfc in this converter.


----------



## lazzer408 (May 18, 2008)

Update:

The 27k is about the best solution I have for now. Any wattage is fine. 1/8w is plenty. I added a pic to show a 1/4w resistor correctly soldered on. I know there is a bridge between the other smt resistors but that's ok because there connected anyways.  I'd would have rather done the volt mod at the IC level. That would have probably worked for the 450 and 650 versions as well IF they used the same pwm controller. For now this is fine. Voltage is very stable at 14.2v +/- 0.02v. To power a 55w HID headlamp, it was drawing .62a off a weak 120v pack. It's drooping to about 110v. so 110x.62=68.2watts input for 55 watt output. Not to bad. Just over 80% efficient. It surprisingly ran off 48v as well with closer to 2 amps draw or 96w in for 55w out or ~57% efficient. -yuk- Point is it's stable with seriously varying input voltage. 

If anyone wants to send me a 450 or 650 I'll figure it out too.


----------



## Qer (May 7, 2008)

lazzer408 said:


> Sometimes I regret not making a profit by buying a bunch and sticking my own label on it and selling them to you guys as dc-dc convertors. I feel that way every time I look in my wallet and look up to see my 1/2 built projects everywhere.


The bad thing is that then you'd get all the complaints too, like if it behaves like an ordinary PC-PSU it'll shut down hard if overloaded instead of gracefully step down to limit the current. Now it's "as is" and you can have the fuzzy, warm feeling without complaints or warranty cases. 

Good find though. One of those will be perfect, whenever I get to the building stage...


----------



## DVR (Apr 10, 2008)

Brilliant idea!!
I must confess tho, that while I'm fairly handy with a soldering iron, and am pretty adept at following instructions like the ones above, I cant follow the tech talk  it's like a foreign language

If you do these mods as described here, are you saying that these will do the job of a $300 DC/DC converter? 
What would the max output in amps be without stressing the thing?


----------



## favguy (May 2, 2008)

At the risk of bieng naive, why do we need DC to DC converters at all? I'll tell you my logic, DC to DC uses power from the main pack and therefore reduces range, range is very important as the range of most EV's is 80 miles at the very most, so with this in mind, is it not better to do as I plan to and have a larger capacity 12v deep discharge battery capable of providing for all expected 12v running load (allowing a sensible factor for diversity) for a period of say 3 hours to a depth of 70%? I've worked out that around 100Ah will do this for mine.

By this time the main pack needs recharging anyway, so the 12v gets charged at the same time as the main pack? 

Just my twopence worth...


----------



## frodus (Apr 12, 2008)

Say you're using a 120V pack, and you need 12V... ignore losses for a second... thats a 1:10 voltage ratio. Say you want 10A on the 12V side. Current and Voltage are inversely proportional with the same load, so 10A on the output side is 1A on the input side. 1A is Nothing when draining your pack.

Now, switch to a 12V battery. You're using 10A out of the battery. Say you run for an hour, and you've got a 20Ah battery... it could run 1.5 hrs just fine (to 75% DOD). It'l take a couple hours to charge that back up to what it needs to be, and it'l take another charger to charge it. Sure there are minimal losses with JUST a 12V battery, but it'l take longer to charge back up. 

With the first option of taking it off the pack, you can charge 120V worth of bats at the same time and give the pack back the lost charge in very little time. 1A isn't much. Even 2A input/20A output isn't much. Its not like you're sucking 20A off the pack, just a couple Amps. Not really enough to do anything to cause you to get less range.

Another thing to consider.... everyone says "lead=range"... so why not put that "extra battery" to use in the HV pack used for the drivetrain.... and have it put to good use.... After all, another battery increases voltage (speed) and range. Your gains in range by putting in another battery and putting it in with the pack would be better than having it seperate and running the accessories off it.

Lots of DC converters are above 85% efficient... minimal losses (we're talking tenths of amps. Thats nothing on a 120V pack. 

Another thing to consider, if its a 20Ah battery running accessories, and you're discharging it at 10A of its 20A rate, the discharge curve might be steeper due to the peukert effect. Its not linear. The more you draw, the less capacity it has. You'd be better off drawing only an amp or so off the HV pack, than you would 10A off one battery.


----------



## Qer (May 7, 2008)

favguy said:


> At the risk of bieng naive, why do we need DC to DC converters at all?


Well, in the end all electricity spent during the trip must be stored in led that has to be hauled around. This is the pros and cons as I see it:

Having an auxiliary battery:
+ Won't draw power from the main battery pack.
+ Dirt simple, low failure rate.
- Must be over dimensioned to not run out before the main pack in case of queue, ie dead weight.

Having a DC/DC:
+ Higher voltage, better light.
+ Will most probably increase range if the same total weight of led is kept.
- Must still have a small battery when DC/DC is off line.

So in the end I think it's up to what you prefer. If you, for example, can't have higher voltage than 144 Volt in the pack and it fits easily in your car you don't gain anything (except from a higher voltage) by excluding the auxiliary battery. If you on the other hand can increase the main pack with another battery if you don't need the auxiliary battery, for example because space is cramped, it can increase both top speed (higher voltage) and range (higher total Wh).

Personally the increased voltage is a reason enough for me, but that's my choice and doesn't mean that I'm Right! YMMV.


----------



## lazzer408 (May 18, 2008)

DVR said:


> Brilliant idea!!
> I must confess tho, that while I'm fairly handy with a soldering iron, and am pretty adept at following instructions like the ones above, I cant follow the tech talk  it's like a foreign language
> 
> If you do these mods as described here, are you saying that these will do the job of a $300 DC/DC converter?
> What would the max output in amps be without stressing the thing?


Find a friend that can help you thru it. It's as simple as putting your pack voltage right to the ac plug to make it work. If you want better efficiency then put your pack voltage to the + and - terminals of the bridge rectifier, as shown, and snip out the rectifier. If you want more voltage output you can add the 27k resistor as shown for 14.2v. That's it. These mods are only for a 250w.

The 250w might be a little on the skimpy side for a car. I chose that because I only have a motorcycle plus I had it kicking around. I guess if you had all LED lighting and didn't plan on a huge stereo you might get away with using the 250w. Headlights alone can draw 10-12 amps. Thermaltake rated the 250w with a 21-amp max load.


----------



## lazzer408 (May 18, 2008)

Here's another DC-DC. It's a Vector Travel Mate 12v 6a adaptor. I bought 3 of these for $7ea. Here's one powering a 55v HID headlamp. Of 120vdc. It's only 72 watts but might be useful for some sort of auxiliary/dedicated power source for a 12v device.

Output 12v 6a
Input 60-144v (roughly)

I have the black and yellow input wires soldered directly to the main capacitor. Yellow is positive.














































The HID above is drawing .56a from the 120vdc batterie pack. You can't see the pack in the picture but it's 10 7ah scooter batteries.


----------



## favguy (May 2, 2008)

Thanks for the input guys, maybe I should rethink this hmm..

On to the converter, is the 450 or 650 watt model likely to have the same circuit board? 

If you use one of these with a small capacity battery to give lights radio etc if parked up with main power off, do you think it's safe to leave it switched on all the time you're running, ie, giving a constant charge to the battery when input current exceeds output current pull, which with the bigger units should be the case


----------



## lazzer408 (May 18, 2008)

favguy said:


> Thanks for the input guys, maybe I should rethink this hmm..
> 
> On to the converter, is the 450 or 650 watt model likely to have the same circuit board?


I doubt it. I'm sure the circuit design will be -similar-. It's a boost convertor (for power factor correction) followed by a push-pull step down converter. There's only so many ways to skin a cat. Send it to me I'll tweak it up to ~14v and post the info for everyone else. I'll send your modified unit back to you ofcorse. You pay shipping.



favguy said:


> If you use one of these with a small capacity battery to give lights radio etc if parked up with main power off, do you think it's safe to leave it switched on all the time you're running, ie, giving a constant charge to the battery when input current exceeds output current pull, which with the bigger units should be the case


I'm not sure I follow you. The input current will never exceed the output current on these converters. The most you'd ever see on the input side is about ~3-4 amps. It should be ok to leave the converter on but I wouldn't leave it unattended. The voltage output is regulated. If a battery is connected, it will charge if you've done the volt-mod for 14v. If the output current exceeds it's current limit the converter will shut down. I believe it's self resetting and will power on again reguardless if the excessive load has been removed or not. It will continue that cycle until the load is removed or it burns up.


----------



## favguy (May 2, 2008)

This 600 watt unit looks like it might be a bargain, if one of you electronic guru types can tweak up the output voltage a little

http://cgi.ebay.com/New-PowerStar-6...oryZ3670QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


----------



## lazzer408 (May 18, 2008)

Update:

Vector 6a DC-DC 14.3v mod. Easy enough. 15k in this one. Any of these converters can be volt modded.


----------



## frodus (Apr 12, 2008)

I think he was asking "do you keep it on when you're in drive mode"

The answer is "Sure". It will charge the battery if the bat voltage is lower than the power supply voltage. Usually in cars/trucks/motorcycles, the DC-DC converter is wired to turn on when the key is in the ignition and turned to ON. 

I don't know why you'd need another battery though, maybe just to smooth out the current when you initially turn lights on... to handle the inrush current. Otherwise, the DC-DC converter should be sized to handle the load anyway. Its not a bad idea... but you'd likely only need a 20Ah battery to smooth things out.

It just won't work when you're "off" and not in drive mode, but the bat will allow you to use accessories for a little while.


----------



## lazzer408 (May 18, 2008)

favguy said:


> This 600 watt unit looks like it might be a bargain, if one of you electronic guru types can tweak up the output voltage a little
> 
> http://cgi.ebay.com/New-PowerStar-6...oryZ3670QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


The ATX type power supply is similar but the low voltage cut off and sensitivity to over current spikes makes it less then idea for an EV. It's just to picky.  Trust me I've already experimented on 3 different ones. I'm not saying it can't be done. It's just alot more work to mod it. You'd have to adjust the low voltage cut-off, adjust the current sensitivity, adjust or eliminate the over voltage protection so your volt mod doesn't cause it to shut down...bla bla bla. pita.


----------



## lazzer408 (May 18, 2008)

Yet some more possible candidates. 

http://www.pyramidcaraudio.com/itempage.asp?model=PSV200 <--- 276 watts continuous

http://www.pyramidcaraudio.com/itempage.asp?model=PSV300 <--- 414 watts continuous

The 30amp one is about $75 shipped off ebay. That's not a bad deal either.


----------



## Dennis (Feb 25, 2008)

While this can be done to make a cheap DC-DC converter it is not something I would use because the components are commercial grade which are only guaranteed to work over temperature ranges of 0C - 70C. Zero degrees centigrade is only 32F which it gets much colder than that up north. Reliability starts to become an issue......I suppose you could change out of the components with automotive or military grade components which can work at much lower and higher temperatures.


----------



## lazzer408 (May 18, 2008)

A DC-DC convertor is no different, component wise, than this. This actually has much higher regulation and is power factor correcting. Considering it's designed for the computer industry and has UL, CUL, TUV, FCC, BSMI and CE certifications, I'll assume it's fairly reliable. I haven't seen that in a commercial DC-DC convertor. The only thing that may effect it over time is vibration and humidity but the open chassis commercial units are just as susceptible to the elements. The PFC PWM IC used is a CM6800G rated for -40 to 125c (that's 257deg F). The capacitors would have exploded by then. Which are all 105c caps by the way.
For what a DC-DC costs I can buy 3 to 6 of these.


----------



## Dennis (Feb 25, 2008)

> A DC-DC convertor is no different, component wise, than this.


Yes I know they use the same components except some extra for the AC-DC conversion for the computer switching power supply.....You seem very confident that a computer power supply will be reliable with all those agency seals on it. If you have such confidence then are you willing to make some test setup for a computer switching power supply in an environmental stress screening chamber? Set the temp to -20C (-4F).


----------



## lazzer408 (May 18, 2008)

Sure...if I could afford it. I can throw it in the freezer for ya.


----------



## Dennis (Feb 25, 2008)

How cold does your freezer get? If it gets cold enough then be all means use that. I test my circuits in the oven at 150F and then put my circuits into the freezer as well. You might be really shocked just how out of spec components can become from temperature changes!


----------



## lazzer408 (May 18, 2008)

I know. I've used ceramic capasitors for thermal sensors before.  You have every right to be the skeptic but for the price can you go wrong? I know they handle short circuit well.  shhh!


----------



## favguy (May 2, 2008)

Domestic freezers usually run at about -18c, just for reference!


----------



## lazzer408 (May 18, 2008)

Well...I'll freeze it when I get a chance. Right now I'm working on something BIG!


----------



## Twilly (Jan 22, 2008)

*Re: Cheapest DC-DC converters. 250w $50, 450w $65, 650w $100 you say?*

Lazzer... I reciever my 450 today... It has 2 - 30 amp outputs... Did you connect both outputs to your car, or only one? 

The info says it is good from 90 to 264V AC... How does that convert to DC?

Thanks for the info on this, And can you give us a hint on your next BIG project...

Twilly


----------



## Dennis (Feb 25, 2008)

> The info says it is good from 90 to 264V AC... How does that convert to DC?


Usually the DC output for full wave rectification will be .636*Vpeak - 1.4 volts of two diode drops. With a capacitor the output voltage will approximately equal the Vpeak of the sine wave assuming no heavy loading.


----------



## Manntis (May 22, 2008)

lazzer408 said:


> For my motorcycle, I use it at 12v without any problem. Why do autos still retain a 12v battery? There's no engine to start with it. Why not put the dc-dc on a switch and power it up first?


So in the event of ignition off when parked, or DC-DC converter failure you can still run your headlights, dome light, brake vacuum pump, carputer (if installed) etc.

edit: oops - this was already answered.


----------



## lazzer408 (May 18, 2008)

*Re: Cheapest DC-DC converters. 250w $50, 450w $65, 650w $100 you say?*



Twilly said:


> Lazzer... I reciever my 450 today... It has 2 - 30 amp outputs... Did you connect both outputs to your car, or only one?
> 
> The info says it is good from 90 to 264V AC... How does that convert to DC?
> 
> ...


Can you get me a few close up shots of the circuit board. Top and bottom. On my 250w I paralleled the outputs. Internally there was only one 12 rail that was fed thru 2 shunts into 2 outputs. The only reason I can track down for the shunts is for the status LEDs. Send me some pics.


----------



## Twilly (Jan 22, 2008)

Here are the pics... I see what you mean, all the leads come from one trace...

What about your next project???


----------



## lazzer408 (May 18, 2008)

On the bottom of pic 005sm is the bridge rectifier I take it. Hook your DC to the + and - legs of it.

What was it I needed pics for? I forgot.  To many projects atm.

You can parallel the outputs if you like. Tie all the yellows together for your positive and all the blacks for your negitive. Or just run a nice piece of 8ga to it. Look near the output traces and you should find a small opto-isolator. There should be a pile of resistors around it. The 12v output of the psu lights up the tx-side LED inside the opto. That's the side you need to tweek. It tells the recieving end what the voltage is. Those resistors make up a voltage divider on both the cathode and anode of the opto. Get me a close up (use camera's macro) of that area.

EDIT - I see them in pic 004sm. Looks like there's 2 in the middle and one on the left side. I -think- it's the right of the two in the middle. It's hard to see the traces. Get a better camera!


----------



## lazzer408 (May 18, 2008)

Twilly said:


> What about your next project???


If ah tell u I haf to keil u


----------



## electro37 (May 18, 2008)

I am going to build an electric bike, and all my experience is from the "dark ages" before solid state etc. I intend using either supercaps or Li Po batteries which apparently need a current controlled charger or "buck" charger as they are known, can anyone help me in this direction?? I can follow electrical and electronic diagrams!! A 5kW propulsion motor would be sufficient.


----------



## lazzer408 (May 18, 2008)

electro37 said:


> I am going to build an electric bike, and all my experience is from the "dark ages" before solid state etc. I intend using either supercaps or Li Po batteries which apparently need a current controlled charger or "buck" charger as they are known, can anyone help me in this direction?? I can follow electrical and electronic diagrams!! A 5kW propulsion motor would be sufficient.


What you want is a half bridge push pull buck converter. Those are a little more complicated then a motor controller. Closer to a 2 phase ac drive.
http://www.hills2.u-net.com/electron/pushpul1.gifhttp://www.hills2.u-net.com/electron/halfbrdg.gif


----------



## KiwiEV (Jul 26, 2007)

lazzer408 said:


> What you want is a half bridge push pull buck converter. Those are a little more complicated then a motor controller. Closer to a 2 phase ac drive.


Lazzer, you're my new best friend. 
I've just bought one of the 450 watt power supplies off Amazon.com and it should be here in a few days. Using a seperate accessories battery worked ok in summer, but now that it's winter and we're driving at night twice as much lately, it's going to be a lot less stress installing a DC-DC converter. 
Anyway, I thought I'd better warn you that I may harass you with some stupid questions in a few days...


----------



## DVR (Apr 10, 2008)

KiwiEV said:


> Lazzer, you're my new best friend.
> I've just bought one of the 450 watt power supplies off Amazon.com and it should be here in a few days. Using a seperate accessories battery worked ok in summer, but now that it's winter and we're driving at night twice as much lately, it's going to be a lot less stress installing a DC-DC converter.
> Anyway, I thought I'd better warn you that I may harass you with some stupid questions in a few days...


Does your missus know your spending your renovation money??


----------



## lazzer408 (May 18, 2008)

No problem. I try to help.  It just dawned on me one day that those would work at 12v and >12+ with a little tweak.


----------



## KiwiEV (Jul 26, 2007)

DVR said:


> Does your missus know your spending your renovation money??


Ssshhhh.


----------



## lazzer408 (May 18, 2008)

Kiwi, did that power supply show up yet?


----------



## impact1 (Jun 25, 2008)

lazzer408 said:


> Update:
> 
> Vector 6a DC-DC 14.3v mod. Easy enough. 15k in this one. Any of these converters can be volt modded.
> 
> images deleated


Do you think these 6amp units would be usable in a motor controller for the gate drive supply? I'd already purchased a Thermaltake 250W for this purpose, bit it seems a bit overkill.

I've also got on order 450W to use in my 12v system, in parrallel with a 7AH gellcell

Mat


----------



## lazzer408 (May 18, 2008)

impact1 said:


> Do you think these 6amp units would be usable in a motor controller for the gate drive supply? I'd already purchased a Thermaltake 250W for this purpose, bit it seems a bit overkill.
> 
> I've also got on order 450W to use in my 12v system, in parrallel with a 7AH gellcell
> 
> Mat


What? Gate drive is only ~12v or so. Why would you want to use an smps for a gate driver? Or how?  If your building your own controller, try an SG3524 pwm. Cheap and easy. Add a TC4422(6a) or TC4452(12a) for the gate driver.

Wait, are you thinking of using a 6a vector as the power supply -for- your controller front end? If so that will work fine. I think that is what you mean.


----------



## impact1 (Jun 25, 2008)

lazzer408 said:


> What? Gate drive is only ~12v or so. Why would you want to use an smps for a gate driver? Or how?  If your building your own controller, try an SG3524 pwm. Cheap and easy. Add a TC4422(6a) or TC4452(12a) for the gate driver.
> 
> Wait, are you thinking of using a 6a vector as the power supply -for- your controller front end? If so that will work fine. I think that is what you mean.


Yes, I would use either this 6amp converter, or the thermaltake 250w converter as the power supply for the TC4422(6a) or TC4452(12a) gate driver chip. And a tap off for the controller chip 5v regulator. I plan to use a PICAXE-18X for the controller, but I've already picked up pair of SG3524 to experiment with as well, based on the you posts in the controller thread.

The 450W would be huge overkill for a gate driver supply. But the 6amp converter doesn't leave much overhead. The 250w units are getting hard to find, as they're discontinued. But I found one at DEALSONIC. <http://www.dealsonic.com/thw0pupoex25.html> 

Still waiting for mine to show up. Have you noticed if the motherboard power sense line is isolated from the output as well as the input? could be useful for remote activation for this application.

Thanks for finding these. I was experimenting with a ATX power supply, but as you point out, their a bit finicky.

Mat


----------



## lazzer408 (May 18, 2008)

impact1 said:


> Yes, I would use either this 6amp converter, or the thermaltake 250w converter as the power supply for the TC4422(6a) or TC4452(12a) gate driver chip. And a tap off for the controller chip 5v regulator. I plan to use a PICAXE-18X for the controller, but I've already picked up pair of SG3524 to experiment with as well, based on the you posts in the controller thread.
> 
> The 450W would be huge overkill for a gate driver supply. But the 6amp converter doesn't leave much overhead. The 250w units are getting hard to find, as they're discontinued. But I found one at DEALSONIC. <http://www.dealsonic.com/thw0pupoex25.html>
> 
> ...


Alot, if not most, of the DIY EV builders arn't designing there own controllers, hence my first reaction wondering what your intentions were. Those gate drivers have a peak rating of 6 or 12 amps. I seriously doubt you come anywhere close to that. I've seen the DIP version of the 4422 used to drive 64 mosfets (buz30a). MCUs don't have a huge power requirement either. Nor does the 3524. You should have any issues at all with the 6a vector supply. Take a look around ebay and if your good at searching you can find smps powersupplies from external cdroms or harddrives that have both a 12 and 5v rail. Here's a few examples.
http://cgi.ebay.com/12V-5V-DC-AC-Po...hash=item360069751254&_trksid=p3286.m14.l1318

http://cgi.ebay.com/REXON-TECH-MODE...hash=item330251370778&_trksid=p3286.m14.l1318
If not find a 12v laptop adaptor. Those are 65-75w. Most, if not all, SMPS powersupplies can run off DC.

The power-on signal on my 250w is NOT isolated from the secondary. I will assume they are all this way to prevent a ground loop.

For what it's worth, Curtis uses a linear regulator (to220) with no heatsink and 2 small (to92) transistors in a totem-pole for their gate drivers. It doesn't take much. Make sure you have a capacitor (100~470uf) mounted close to the driver and keep the path from the driver to gate short as possible. Don't forget gate resistors.


----------



## KiwiEV (Jul 26, 2007)

lazzer408 said:


> Kiwi, did that power supply show up yet?


Not yet but it should be here before the weekend. It may be using US Post, in which case I'd better get comfy (from my many US Post experiences).


----------



## ww321q (Mar 28, 2008)

Hay Gav. I'm sure you have heard what we call the US Postal Service here "Snail Mail" J.W.


----------



## lazzer408 (May 18, 2008)

I was thinking about the whole idea of retaining the 12v battery (in a motorcycle) for the lights ect. What are the odds of a dc-dc failure? What I might do is just toss in a dpdt switch and tap one of the traction batteries should a dc-dc failure occur. If I went with a relay I could even automate it. All of the grounds in my bike have been isolated from the chassis so no worries there. Opinions?


----------



## e_canuck (May 8, 2008)

Hi Lazzer.

You are a genius and I am unworthy.

I like that idea. Not just for motorcycle but any vehicule. You save the weight of the accessory battery for the life of the vehicule. maybe get an extra pack battery and still be within the max gross weight. Tapping a pack battery, in order to finish a trip and get back to home base, would be a rare event with very litle consequence.

Automatic would be preferable, because of night driving. I would just add a warning light/led to indicate the fault/switchover.

DP


----------



## impact1 (Jun 25, 2008)

lazzer408 said:


> I was thinking about the whole idea of retaining the 12v battery (in a motorcycle) for the lights ect. What are the odds of a dc-dc failure? What I might do is just toss in a dpdt switch and tap one of the traction batteries should a dc-dc failure occur. If I went with a relay I could even automate it. All of the grounds in my bike have been isolated from the chassis so no worries there. Opinions?


I was thinking about this myself in regards to a car. In the case of the car I was thinking that including the nesacery cableing to do this sort of chang over would be the best solution. In a car you're running alot current to the motor. So any "switch" would have to handle all that current. I'd also be concerned about a faulty device shorting the two power domains togather. It would be cheaper and safer and most likely weigh less to hav a second dc/dc converter. But my plan is to use a smaller battery in parrallel with a DC/DC converter. My typical travel time will be 30 minutes max each direction. With only essentials, headlights and LED signals, I could stagger home with a 7AH gelcell.

I'm not sure what kind of current you'll be pushing to your motor on a bike, but high current switches and or contactor/relays are expensive. And don't you need a DPDT and SPST as well? If you're concerned about a failur of the DC/DC I'd include a small battery and or a backup 6amp converter. The second unit could switch in automaticlly if the first fails.

I do like the idea of a warning light to let you know of a DC/DC failure, a replacemnt for the alternator light. The car I'm converting, a Triumph GT6, has 3 idiot lights built into the speedometer, and 2 built into the Tach.

Mat


----------



## lazzer408 (May 18, 2008)

impact1 said:


> I was thinking about this myself in regards to a car. In the case of the car I was thinking that including the nesacery cableing to do this sort of chang over would be the best solution. In a car you're running alot current to the motor. So any "switch" would have to handle all that current. I'd also be concerned about a faulty device shorting the two power domains togather. It would be cheaper and safer and most likely weigh less to hav a second dc/dc converter. But my plan is to use a smaller battery in parrallel with a DC/DC converter. My typical travel time will be 30 minutes max each direction. With only essentials, headlights and LED signals, I could stagger home with a 7AH gelcell.
> 
> I'm not sure what kind of current you'll be pushing to your motor on a bike, but high current switches and or contactor/relays are expensive. And don't you need a DPDT and SPST as well? If you're concerned about a failur of the DC/DC I'd include a small battery and or a backup 6amp converter. The second unit could switch in automaticlly if the first fails.
> 
> ...


The only current needed from one of the traction batteries would be the 6a needed to run the lights. A very small relay can handle that just fine.

You can use an op-amp to detect the voltage from the dc-dc. >12v=light off, <12v=light on. Simple enough.


----------



## KiwiEV (Jul 26, 2007)

Rightio, my power supply arrived and I'm going to try and up the voltage from 12v to 13.8v to give the headlights that extra brightness and to help keep the accessories battery at a healthy level. I'm keeping the accessories battery as I need some way to "start" the main contactor, which then fires up the DC-DC converter.

Here's an picture of the circuit board:









So, Lazzer matey, this is where you chime in...  Can you give me some instructions on how to up the output voltage to around 13.8 volts? Any area of the circuit you want a close-up of?


----------



## lazzer408 (May 18, 2008)

KiwiEV said:


> Any area of the circuit you want a close-up of?


Hi Kiwi. In the picture you see the large cap in the middle? There are 2 4-pin dip optoisolators 45-deg up and right. One of those -might- be the voltage feedback. There could be many. I will need pics of the bottom of the board. This is the 450w one correct?


----------



## lazzer408 (May 18, 2008)

If someone wants to send me a 450w psu I'll mod it for you for free (you pay return shipping) just so I can figure it out for the rest of you. Maybe I could hold a virtual raffle for one? All I need is 50 people to buy $2 virtual tickets and the winner gets the modded supply.


----------



## impact1 (Jun 25, 2008)

lazzer408 said:


> If someone wants to send me a 450w psu I'll mod it for you for free (you pay return shipping) just so I can figure it out for the rest of you. Maybe I could hold a virtual raffle for one? All I need is 50 people to buy $2 virtual tickets and the winner gets the modded supply.


I'm game for sending a supply. My 450w supply arrived a few days ago. I'm going to try and and get by with a 250w supply in my car, so I can afford to have the 450w disappear for a while.

Send me you address, and I'll send it out with some return postage funds.

Mat Clayson


----------



## lazzer408 (May 18, 2008)

impact1 said:


> I'm game for sending a supply. My 450w supply arrived a few days ago. I'm going to try and and get by with a 250w supply in my car, so I can afford to have the 450w disappear for a while.
> 
> Send me you address, and I'll send it out with some return postage funds.
> 
> Mat Clayson


Great. I pm'd you my address. Don't hold me responsible if something bad happens. Don't worry, I won't go blindly poking around. 

When returned, do you want it left converted to 13.8v output? I can gut the AC side as well if you only plan on using DC power. This way I can take alot of photos and show what can and can't be removed/modded.

Did you buy a 250w and do the volt mods I posted?

I'm sure Kiwi will thank you. Won't you Kiwi?! 

edit - oh by the way. If you convert your whole car to LEDs and maintain the 55/65w headlights, your -just- going to make it with a 250w psu. Your headlights are about ~6a each, ~1 amp for the LEDs (including the instrument cluster), and ~3a for a contactor is 220.8w (16a*13.8v) plus any misc loads. It's cutting it close. Your much better off using the 450w at 1/2 load then you are the 250w at full load.


----------



## KiwiEV (Jul 26, 2007)

lazzer408 said:


> Hi Kiwi. In the picture you see the large cap in the middle? There are 2 4-pin dip optoisolators 45-deg up and right. One of those -might- be the voltage feedback. There could be many. I will need pics of the bottom of the board. This is the 450w one correct?


Yup, it's the 450w one. If this doesn't work then I might send it to you but it would be a last resort as it would cost quite a bit in freight, plus there's the waiting for freight etc.
Anyway, here's a picture of the two opti-thingys I think you're talking about?









And here's a picture of the bottom of the circuit board:








If you want me to send you the full sized file let me know as it's too big to attach here and photobucket resizes it. 
I cropped this section out however:








It shows the area where the underside of the two opti-thingys are.

Oh and feel free to use this one as a guinea pig for the others to learn from.


----------



## lazzer408 (May 18, 2008)

There are 3 of them as circled. I believe one is the power on signal to the primary side. I'll study this awhile and see what's what on the other two. brb

Ok Kiwi. Rough guess (very rough) R33, r37, r38, and maybe r157 but I'm not sure on that one. One of those -should- directly effect the voltage output. If you want to take the hunt-and-peck approach you can parallel a resistor one at a time and note the effects. Start out with a 10k-50k resistor to poke with. Keep a load on the psu when you do this. An 1156 (back up light) will be fine. Throw on the DVM and poke away. Be carefull!! There is high voltage on that board and will remain after you unplug it. Use a 60w light bulb to discharge the main cap. It's rated at 400v looks like.

If I could see better I could draw out the schematic and figure it out from that. If you can hang in there awhile user Impact is hopefully sending one my way to figure out.


----------



## KiwiEV (Jul 26, 2007)

Cool bananas, thanks for that. It'll be a few days before I can do any actual fiddling as I'm waiting for good weather and a sheltered place to pop the car's bonnet. I'll wait for your sound advice when you get your hands on Impact's PSU. 
This is very valuable advice and I appreciate the effort you're going to.


----------



## lazzer408 (May 18, 2008)

KiwiEV said:


> Cool bananas, thanks for that. It'll be a few days before I can do any actual fiddling as I'm waiting for good weather and a sheltered place to pop the car's bonnet. I'll wait for your sound advice when you get your hands on Impact's PSU.
> This is very valuable advice and I appreciate the effort you're going to.


No problem my foreign friend.  Have patience and, if impact1 pulls through, we'll get this figured out the right way.


----------



## ngrimm (Oct 19, 2007)

Hello all. I believe someone said these power supplies might work down to a 90 volt dc input. Can you think of a way to make this work with a 72 volt input for lead acid motorcycle guys like me. I would like to power the controller and accessories. Appreciate any ideas you may have. Thank you. Norm


----------



## lazzer408 (May 18, 2008)

ngrimm said:


> Hello all. I believe someone said these power supplies might work down to a 90 volt dc input. Can you think of a way to make this work with a 72 volt input for lead acid motorcycle guys like me. I would like to power the controller and accessories. Appreciate any ideas you may have. Thank you. Norm


Somewhere in the thread is mention of the Vector adaptor. It was working down at 48v if I remember correctly. You may have to derate the output. Normally 6a. Enough for everything but the headlight unless you use a 35w HID.

edit - sorry. The vector was 60v http://www.diyelectriccar.com/forums/showpost.php?p=42186&postcount=25 I had the 250w running at 48v though.


----------



## impact1 (Jun 25, 2008)

lazzer408 said:


> Great. I pm'd you my address. Don't hold me responsible if something bad happens. Don't worry, I won't go blindly poking around.
> 
> When returned, do you want it left converted to 13.8v output? I can gut the AC side as well if you only plan on using DC power. This way I can take alot of photos and show what can and can't be removed/modded.
> 
> ...


Laz,

Got the address, I'll drop the 450W off at the PO on Saturday. I may be using this as a home backup charger, so leave the AC front end intact. But converting to 13.8 volts would be great.

My work has been brutal for the last 8 weeks, and I expect it to last a at least another 3 weeks.  So untill then no hacking the 250W. 

My car is tiny, with only lights and a low power radio. I'll also be using a 12v 8AH gell cell, which will be getting topped off while the main pack charges So I think the 250W will do the job, but we'll see.

Impact1


----------



## etischer (Jun 16, 2008)

Thanks for sharing Lazzer! Contributors like you are what really make the forum work. 

I bought the 650 Watt unit today, and plan on poking and hoping with resistors to get my 13.8V. I can post pics of the board if poking and hoping doesn't work, and hopefully you can lend a hand. 

I'm powering the supply from 300vdc, which is rectified 208vac. The drive says it's capable of 90-264vac so I assume 300vdc is ok to connect to the input or output of the rectifier. 

It says Min load is 0.1A, will the supply get damaged if powered on with no load? 

Thanks again for your contribution
Eric.


----------



## lazzer408 (May 18, 2008)

etischer said:


> Thanks for sharing Lazzer! Contributors like you are what really make the forum work.
> 
> I bought the 650 Watt unit today, and plan on poking and hoping with resistors to get my 13.8V. I can post pics of the board if poking and hoping doesn't work, and hopefully you can lend a hand.
> 
> ...


I'm not sure if the unit would be damaged or if it just wouldn't turn on without a load. As far as the voltage, your rectifier/filter is no different then what they do internally, less some filter chokes. Your 208vac is less then the rated 264vac handling. You should be fine. It's better to connect your DC to the output of the psu's rectifier just to save the voltage drop and related heat. There feedback opto circuit is a bit confusing. Poke carefully. 

Post pics.


----------



## lazzer408 (May 18, 2008)

impact1 said:


> Laz,
> 
> Got the address, I'll drop the 450W off at the PO on Saturday.


Great. It shouldn't take long to figure it out. I'll post pics of the mod when it's done. You sure on 13.8v? If you want to charge with it maybe 14.2v would be better? Want a knob on it? haha That's extra.


----------



## KiwiEV (Jul 26, 2007)

lazzer408 said:


> Great. It shouldn't take long to figure it out. I'll post pics of the mod when it's done. You sure on 13.8v? If you want to charge with it maybe 14.2v would be better? Want a knob on it? haha That's extra.


Hmm, good point. Do you think 14.2 volts would be better?


----------



## lazzer408 (May 18, 2008)

KiwiEV said:


> Hmm, good point. Do you think 14.2 volts would be better?


Well... 13.8v is a good float voltage or slow charge but 14.2v would be better for charging a dead battery. If the dc-dc is going to be used for your vehicle lighting etc, and the aux battery just sits there, then 13.8v would be fine. It's common to see 14.2v charging systems on the stock ice engine, so it can quickly recover from cranking the engine, but in an EV the aux battery doesn't get discharged unless you left the lights on or something. Even so 13.8v can recharge the battery, only slower.
So...
As a dc-dc 13.8v
As a charger. 14.2v


----------



## lazzer408 (May 18, 2008)

I'm waiting for impact (OR ANYONE) to send me a 450 and/or 650 to mod it. He said he was sending one but I haven't recieved anything.


----------



## todayican (Jul 31, 2008)

I was going to do it, but have decided to go with an aux battery. Its worth saying that Jeff (Lazzer) is a great guy!


----------



## lazzer408 (May 18, 2008)

todayican said:


> I was going to do it, but have decided to go with an aux battery. Its worth saying that Jeff (Lazzer) is a great guy!


What keeps that battery charged? Go with a 450w. Small and light.

So who's got a 450 or 650 sitting around to send me? Or if you plan on getting one, have it shipped to me to mod so I can get a walkthru put together for them.


----------



## KiwiEV (Jul 26, 2007)

lazzer408 said:


> What keeps that battery charged? Go with a 450w. Small and light.
> 
> So who's got a 450 or 650 sitting around to send me? Or if you plan on getting one, have it shipped to me to mod so I can get a walkthru put together for them.


Holy cow. Has Impact1's not arrived yet? Impact - have you sent it yet mate?
This is a problem as my aux battery is now pretty sick and only offers 15 minutes of headlights. I'm getting hounded by a wife that wants the car running properly at night.

Jeez Lazzer, I might have to send _mine_ all the way from here if no one in the USA can post theirs. It would take a month or two to get mine to you though.

Help! Anyone in the USA with a psu, please send it to Lazzer!!!


----------



## Joel (Jul 29, 2008)

hey gavin, you can probably just use the 12V power supply to replace the accesories battery all together (temporarily of course)
i was originally planning on doing that, but then i saw some saftey regulation stuff.. i guess it makes sense that your 4 way blinkers should work without a key in the ignition

btw.. i'm a huge fan, i'll be doing a website like yours once i get started


----------



## lazzer408 (May 18, 2008)

KiwiEV said:


> Holy cow. Has Impact1's not arrived yet? Help! Anyone in the USA with a psu, please send it to Lazzer!!!


Impact1's psu has not shown up.

etischer has steped up to the plate and offered his though. 

Kiwi, send me a box of Remembrances. lol


----------



## ElectriCar (Jun 15, 2008)

http://www.newegg.com/Product/Product.aspx?Item=N82E16817153034

Is this the 650 unit? They also have a 1200W system for $380 or so.


----------



## impact1 (Jun 25, 2008)

lazzer408 said:


> Impact1's psu has not shown up.
> 
> etischer has steped up to the plate and offered his though.
> 
> Kiwi, send me a box of Remembrances. lol


I'm sorry all.

I've had a family emergancy. With my wifes sister collapsing in a siezure. Unfortunatly she has a brain tumor. We eneded up driving out to be with her in SoCal, and taking care of her kids. We got back this weekend with her 3 boys with us. I can still send out the PS if it's needed.

Sorry for the delay.

Mat Impact1


----------



## lazzer408 (May 18, 2008)

ElectriCar said:


> http://www.newegg.com/Product/Product.aspx?Item=N82E16817153034
> 
> Is this the 650 unit? They also have a 1200W system for $380 or so.


http://www.amazon.com/Thermaltake-W...1?ie=UTF8&s=electronics&qid=1218607609&sr=1-1

$99.99  

Impact1 - We got it covered thanks.


----------



## KiwiEV (Jul 26, 2007)

impact1 said:


> I'm sorry all.
> 
> I've had a family emergancy. With my wifes sister collapsing in a siezure. Unfortunatly she has a brain tumor. We eneded up driving out to be with her in SoCal, and taking care of her kids. We got back this weekend with her 3 boys with us. I can still send out the PS if it's needed.
> 
> ...


Crikey, I'm sorry to hear that. Family comes first so I completely understand why you've been busy. I think we should be all good for the psu front as Etischer is sending his. Once the instructions are known, we should start a wiki thread teaching the world how to save a few hundred bucks on a DC-DC converter. 
And kudos to Lazzer for using his electronics wizard superpowers to fight evil!


----------



## lazzer408 (May 18, 2008)

KiwiEV said:


> kudos to Lazzer for using his electronics wizard superpowers to fight evil!


BWA HAHAHAHA!



Actually, Impact1, You have a 450w right? I think Etischer is sending a 650w. If you want to send the 450w I can compair them and make sure both models are covered.

Etischer - Which psu are you sending?


----------



## etischer (Jun 16, 2008)

I have the 650w. The circuit board looks identical to Kiwis 450w, just bigger heat sinks and caps. 

http://www.diyelectriccar.com/forums/ 
I got my bus bars put together, and stayed up late to get the power supply back in one piece so I can mail it off. I'll try to get it shipped out tomorrow. 













lazzer408 said:


> BWA HAHAHAHA!
> 
> 
> 
> ...


----------



## KiwiEV (Jul 26, 2007)

etischer said:


>


Wow, are you building your own controller there? Why all the capacitors & bus bars?


----------



## lazzer408 (May 18, 2008)

KiwiEV said:


> Wow, are you building your own controller there? Why all the capacitors & bus bars?


Yeah he is. He's one of those "ac people"


----------



## etischer (Jun 16, 2008)

Ok, my power supply is "in the mail". I dropped it off at the post office, its shipping 2nd day.


----------



## KiwiEV (Jul 26, 2007)

Awesome! Thanks Etischer! I owe you one! Any time you're near my place pop in for a beer.

Hmmm. Failing that, here's an e-beer.


----------



## Dogbert (Jul 23, 2008)

Hey guys,
Been following the thread in anticipation that someone would beat me to the 450 mod!
Soon as I saw the thread - got me a 450W and started tinkering.
I first thought of having a relay energized by the 12v of the 450W and if it stops it will drop out and swap over to a 17AH emergency SLA (that would be kept topped up with a booster and a solar style charger regulator).

Then someone reminded me of the Keep It Simple Stupid phrase, and that it should replicate the battery and alternator of a car as closely as possible. The car runs off the battery and the alternator just keeps it topped up. (I can hear the echos of people yelling at their monitor so far saying "tell us something we don't know!")

Yes have started trying to work out the circuit on the 450W. I don't want to go blindly poking a resistor in parallel as yet. (maybe tomorrow)

If all else fails there is the option of coating my thumb in conductive laquer, closing my eyes and randomly mashing the PCB! Kidding


----------



## etischer (Jun 16, 2008)

I just might be knocking on your door come may next year =)

I was thinking about this earlier today... Imagine you are in a panic stop, the abs motor kicks in and it could overload the power supply. It would be a practical test to perform even if you are using a parallel 12v battery. ABS motor is probably the second highest current draw on a typical car, and it's a pure inductive load which switching power supplies hate. 




KiwiEV said:


> Awesome! Thanks Etischer! I owe you one! Any time you're near my place pop in for a beer.


----------



## lazzer408 (May 18, 2008)

etischer said:


> I was thinking about this earlier today... Imagine you are in a panic stop, the abs motor kicks in and it could overload the power supply. It would be a practical test to perform even if you are using a parallel 12v battery. ABS motor is probably the second highest current draw on a typical car, and it's a pure inductive load which switching power supplies hate.


I disable my abs. I don't need a car manufacture telling me how to control my vehicle. I already know. I say, Learn how to drive! If you need abs to control your vehicle for you, you shouldn't be on the road and your following too close! 

Those who use a battery along with the dc-dc shouldn't have a problem with the inductive loads like the abs, or the blower motor. Ever see the lights dim when you flip that blower to high? But to others, who want this to be a replacement for the battery, you can try adding a large capacitor in parallel. To big of a cap and the surge of charging it could shut it down too. -doh- Hopefully the fact that this is pfc should make it a bit more accepting to abuse.


----------



## etischer (Jun 16, 2008)

Unfortunatly manufacturers are no longer putting proportioning valves in, they are relying on abs to prevent rear lockup. Not only does this cause the ABS to kick in much more frequently, it also makes the rear lock up sooner if ABS is disabled. Just something to consider before disabling abs.



lazzer408 said:


> I disable my abs. I don't need a car manufacture telling me how to control my vehicle. I already know. I say, Learn how to drive! If you need abs to control your vehicle for you, you shouldn't be on the road and your following too close!
> 
> .


----------



## Madmac (Mar 14, 2008)

Some designs of switchmode power supplies will lock out on starting if the feedback is high. This can be caused by connecting the output directly to a battery. If this occurs then a diode will be needed in series with the output, or a relay to pull in after power is applied.

Is probably worth putting a high power clamp diode across the output as the design is low cost and the power diodes are probably not that high a voltage rating when dealing with spikes.


Lazzer408
From the photos it looks like it might be feasible to mount upside down onto a metal plate and then a water cooled heat sink (along with the other power devices). I take it that some heatsinks are at a raised potential.

Does this seem a viable mounting method?

Madmac


----------



## rfengineers (Jun 2, 2008)

I've been lurking on this thread for quite a while. My power supply arrived yesterday and I put it on the bench to play with. Switching power supplies are not my forte so I am relying on the expertise of lazzer.

Lasser indicated earlier that resistors R33, 38 and 157 might be the components to adjust to change the output voltage. I sketched out a rough diagram of that part of the circuit, see the picture at: 

http://www.rfsoftware.com/DIY/Thermaltake-450sm.png

My eyes are old so I may not have gotten it right. Perhaps someone else can confirm my work.

I hooked the PSU to a 5-ohm load and measured the voltage on each side of R33. It measured 10.15 Volts closest to the optoisolator and 12.00 Volts on the other side. I changed the load to 2.5-ohms and read 10.20 and 12.00 Volts.

So, can any of you really smart guys come to any conclusion based on this?


----------



## rfengineers (Jun 2, 2008)

rfengineers said:


> I've been lurking on this thread for quite a while. My power supply arrived yesterday and I put it on the bench to play with. Switching power supplies are not my forte so I am relying on the expertise of lazzer.
> 
> Lasser indicated earlier that resistors R33, 38 and 157 might be the components to adjust to change the output voltage. I sketched out a rough diagram of that part of the circuit, see the picture at:
> 
> ...


I noticed that my scope was indicating -0.15 volts when not connected! I recalibrated and measured again. The new numbers are 12.15-to-12.20 Volts and 10.35-to-10.40 Volts. The voltage seems to be load independent.


----------



## lazzer408 (May 18, 2008)

Madmac said:


> Lazzer408
> From the photos it looks like it might be feasible to mount upside down onto a metal plate and then a water cooled heat sink (along with the other power devices). I take it that some heatsinks are at a raised potential.
> 
> Does this seem a viable mounting method?
> ...


Sure. But I don't know if they need to be isolated.


----------



## lazzer408 (May 18, 2008)

rfengineers said:


> Lazzer indicated earlier that resistors R33, 38 and 157 might be the components to adjust to change the output voltage. I sketched out a rough diagram of that part of the circuit, see the picture at:
> 
> http://www.rfsoftware.com/DIY/Thermaltake-450sm.png
> 
> My eyes are old so I may not have gotten it right. Perhaps someone else can confirm my work.


I have the psu here now. Give me a few days (kids in town) and I'll have it worked out for you guys.

U3 looks like it's for the turn-on signal being that it's connected to a transistor. U5 would be for feedback then. The circuit looks just like the 250w. What's strange about the way Thermaltake did this is that the opto isn't tied directly to ground. It's floating and just measuring the voltage drop across R157. Lowering R157 may work. Increasing R33 might do it but if I remember the 250w it was actually a resistor in position like R37/38 is in rfengineers drawing.

rfengineers: Where do R38 and R38 run off to at there common terminal? You are correct about the voltage being load independent. It's the voltage regulator and if it's doing it's job the voltage won't change. 

I'll know soon enough and post the mods with close-up pics.


----------



## rfengineers (Jun 2, 2008)

lazzer408 said:


> rfengineers: Where do R38 and R38 run off to at there common terminal? You are correct about the voltage being load independent. It's the voltage regulator and if it's doing it's job the voltage won't change.


I looked a little closer at the area-in-question. I had r157 wrong. Here is an updated schematic: http://www.rfsoftware.com/DIY/Thermaltake-Update.JPG

R157 connects to the regulator (TL431).

FYI: here is a picture of my super-sophisticated test setup: http://www.rfsoftware.com/DIY/Fancy_Setup.JPG

And pictures of my current conversion project:
http://www.rfsoftware.com/DIY/Sunfire-ICE.png
http://www.rfsoftware.com/DIY/Sunfire-Tranny.JPG


----------



## lazzer408 (May 18, 2008)

rfengineers said:


> I looked a little closer at the area-in-question. I had r157 wrong. Here is an updated schematic: http://www.rfsoftware.com/DIY/Thermaltake-Update.JPG


There's more to it. Where does the 12v ref voltage come in at? I don't know which pin is v-ref on the 431 either unless you label it.  You need the full number suffix to know the correct 431 pin-out from a datasheet. 

I'll dig around with it later tonight.


----------



## rfengineers (Jun 2, 2008)

lazzer408 said:


> There's more to it. Where does the 12v ref voltage come in at? I don't know which pin is v-ref on the 431 either unless you label it.  You need the full number suffix to know the correct 431 pin-out from a datasheet.


UTC 
TL431K 
VAF


----------



## rfengineers (Jun 2, 2008)

Trying to trace out this circuit is driving me crazy!! Every time I do it I get something different. I have posted a closeup of the portion of the ckt board at: 

http://www.rfsoftware.com/DIY/Regulator-closeup.JPG

The regulator, TL431, is the three 'through-holes' directly below the R37 label. 
The connection furthest from the R37 label is the cathode, 
The connection closest to the R37 label is the reference input,
The anode is in the center.

I'm going to have a cup of coffee and try again.


----------



## rfengineers (Jun 2, 2008)

OK, this is it (I think). I am 99 and 44/100 percent sure this time. It looks like this:

http://www.rfsoftware.com/DIY/99p44percent.JPG

Is the circuit, and R34 controls the voltage. But I think I will wait for Lazzer's opinion on the matter.


----------



## lazzer408 (May 18, 2008)

rfengineers said:


> UTC
> TL431K
> VAF


I can't find the vkf so I dunno which pin is vref.



rfengineers said:


> OK, this is it (I think). I am 99 and 44/100 percent sure this time. It looks like this:
> 
> http://www.rfsoftware.com/DIY/99p44percent.JPG
> 
> Is the circuit, and R34 controls the voltage. But I think I will wait for Lazzer's opinion on the matter.


I should have something for you guys tonight when the kids go to bed and I can have some QUIET.


----------



## rfengineers (Jun 2, 2008)

lazzer408 said:


> I can't find the vkf so I dunno which pin is vref.


Aren't all the TO-92s the same pinout? 1=ref, 2=anode, 3=cathode

Does the most recent schematic make any sense to you? That would be this one: http://www.rfsoftware.com/DIY/99p44percent.JPG


----------



## rfengineers (Jun 2, 2008)

I put 100K across R39 (19.6k 1%). That should have reduced the value to (about) 14.8k. The output dropped to 10.5V


----------



## lazzer408 (May 18, 2008)

rfengineers said:


> Aren't all the TO-92s the same pinout? 1=ref, 2=anode, 3=cathode
> 
> Does the most recent schematic make any sense to you? That would be this one: http://www.rfsoftware.com/DIY/99p44percent.JPG


I'll compair it to what I have done on the 250w. I did the board layout on a drawing then drew in the traces then made the schematic. I have since lost it.  I'm looking at the 250w at the moment. The second schematic looks right. I'll check it over later.


----------



## lazzer408 (May 18, 2008)

rfengineers said:


> I put 100K across R39 (19.6k 1%). That should have reduced the value to (about) 14.8k. The output dropped to 10.5V


Hint-Pull it low. (ground it)


----------



## rfengineers (Jun 2, 2008)

lazzer408 said:


> Hint-Pull it low. (ground it)


Do you mean pull the junction of r34 and r39 low through a resistor? R34 is only 10-ohms and has 12 volts on the other side of it!

Or do you mean ground the reference input to the regulator?


----------



## lazzer408 (May 18, 2008)

Pull pin 1 of the shunt regulator lower with a resistor. The shunt regulator is an adjustable zener. It's regulating the 9.3v you measured. Raise the 9.3v and it will take more then 12v to get the same 1.1v across the opto.
The ~? is probably secondary ground. In that case just parallel something with R50. Start high.

I think you have the opto-isolator drawn backwards. 

I got tied up last night and will be busy this afternoon as well. Sorry for the delay.


----------



## rfengineers (Jun 2, 2008)

lazzer408 said:


> Pull pin 1 of the shunt regulator lower with a resistor. The shunt regulator is an adjustable zener. It's regulating the 9.3v you measured. Raise the 9.3v and it will take more then 12v to get the same 1.1v across the opto.
> The ~? is probably secondary ground. In that case just parallel something with R50. Start high.


I put a 100k pot across R50. As I reduced the resistance across R50 the output voltage went up. If I go too far the PSU shuts down.

At 34.4k-ohm across R50 I measure 13.28V at the PSU output and 13.60V at the junction of R33 and R34.


----------



## lazzer408 (May 18, 2008)

Can you enter the aprox. values of all resistors? r50, R34, and r39, in particular.

r34 and r39 (regulator vref) may need to be increased if the 'low pull' method isn't cooperating. That or increase r33 to lower the opto's available current. The 3rd option is a resistor in parallel with the opto (r157).

This is all assuming your schematic is correct.

I'm going to try and get to it tonight. Between 2 kids and 2 broke down cars im going nuts.  If there is a high voltage cut-off being activated this will harder to figure out. I didn't have that issue with the 250w. I'll keep you posted.


----------



## rfengineers (Jun 2, 2008)

lazzer408 said:


> Can you enter the aprox. values of all resistors? r50, R34, and r39, in particular.
> 
> r34 and r39 (regulator vref) may need to be increased if the 'low pull' method isn't cooperating. That or increase r33 to lower the opto's available current. The 3rd option is a resistor in parallel with the opto (r157).
> 
> ...


I redrew the schematic with component values.

http://www.rfsoftware.com/DIY/Thermaltake-Update2.JPG

I have the kid thing beat, I just send the grandkids back to their parents!


----------



## lazzer408 (May 18, 2008)

rfengineers said:


> I redrew the schematic with component values.
> 
> http://www.rfsoftware.com/DIY/Thermaltake-Update2.JPG
> 
> I have the kid thing beat, I just send the grandkids back to their parents!


Is r34 and r39 easy to remove one leg of either?


----------



## rfengineers (Jun 2, 2008)

lazzer408 said:


> Is r34 and r39 easy to remove one leg of either?


They are both surface mount chip resistors. That area of the circuit board is not very crowded, so it should not be too difficult to remove/replace one by hand.


----------



## rfengineers (Jun 2, 2008)

Rather than reducing the value of R50 as we are now doing, do you think it would be better (more stable?) to increase the value of R34+R39? I am not sure exactly how the TL431 operates but the data sheet examples show a pot in that location rather than across the anode and reference pins.

It would be fairly simple to remove the 10-ohm, r34 resistor and insert a pot in its place.

I should be able to do that a little later this afternoon.


----------



## Dogbert (Jul 23, 2008)

Rfengineers, 
I see where you're going with the R34 + R39. I would have tried it but I don't have any low ohm pots on hand. (When is the 24hr Jaycar when you want it?!)

You were on the right track with R50. I put a multiturn pot across R50 -

At 28k the output voltage got to 13.8v just on (13.79v approx) but was unstable in the respect that the overvoltage protection was just sitting on the edge of turning off. 1/2 of the time it did kick-in and shut down the PSU.

At 30k the output voltage was at 13.6v (stable)

I was using a headlight as the load.

I don't know if it is the correct way of going about it, but it did work (kind of).
Has anyone found what part of the PCB controls the overvoltage shutdown? If we can raise this threshold then it may be stable enough for us to use.


----------



## rfengineers (Jun 2, 2008)

I've removed R34 (the 10-ohm resistor) and replaced it with a pot. I can increase the pot to about 2900-ohms before the overvoltage circuit shuts down the PSU. At 2900-ohms I have about 13.3 Volts out.

When the PSU shuts down the reference voltage on the TL431 goes to zero.


----------



## lazzer408 (May 18, 2008)

rfengineers said:


> I've removed R34 (the 10-ohm resistor) and replaced it with a pot. I can increase the pot to about 2900-ohms before the overvoltage circuit shuts down the PSU. At 2900-ohms I have about 13.3 Volts out.
> 
> When the PSU shuts down the reference voltage on the TL431 goes to zero.


It looks like I might have to dig into this over voltage issue as well. I'm tinkering with it now. The regulator going to 0v is probably because the psu shutdown. The regulator itself doesn't just turn off on it's own. It's an adjustable shunt regulator which is an adjustable zener.

If other people are already modding this, why not post the information? 
It's good it'll do 13v+ but we need 14.2v imo.


----------



## Dogbert (Jul 23, 2008)

lazzer408 said:


> If other people are already modding this, why not post the information?
> It's good it'll do 13v+ but we need 14.2v imo.


Because this has been one BIG refresher course in electronics for me!
I've only learned basic electronics and digital electronics quite a few years ago! I'm way behind you guys in knowledge but i'll get there!

I'm trying to work out where the overvoltage cutout is atm. 
Yes true, we do need 14.2 or preferably 14.4v if we use a high power diode to stop back-feed when the PSU gets turned off.
I think one would be needed. When I hooked up a battery with 13.6v and turned off the PSU, it then turned ALL the lights on at the front (I'm only running off one line - one light) even though it was off. There would have been some wasted current at that time. I'll do another run and try to measure it. 
ALSO - even at 13.6 The PSU could not be switched on / powered up with the battery attached on the output. It had to be connected after the PSU was running ok. A diode MAY fix this - I'll try it out...


----------



## KiwiEV (Jul 26, 2007)

Help! My wife keeps asking me when we can drive at night again! Anyone having any luck with uppink ze woltage on the PSU?
My accessories battery has been getting drained flat every day and now it only lasts about 5 minutes with the headlights on. 
Help! Free soft-toy kiwi to the first person to get it working and post the instructions (in very basic english) for us non-technical people!

That's right, one of these could be yours!








Get cracking you technical wizards! Use your super brainpower to fight evil! (and dying accessories batteries)


----------



## rfengineers (Jun 2, 2008)

Wow, and I thought a Kiwi was a fuzzy green fruit that tasted like strawberry!

I have been working on this project in my spare time, but at the moment I am more concerned with the 8-to-12 inches of rain the weather guessers are predicting for this evening. It seems that there is a large rotating wind/rain thing heading directly for me.

http://www.rfsoftware.com/DIY/TS-Fay.png

I am guessing that there is an overvoltage crowbar (they are usually an SCR) somewhere on the circuit board. I have, as yet, been unable to locate it. I have found two chips mounted underneath the board in areas that may contain the overvoltage control. Both chips are labeled eZ807. I don't know what they are but I suspect they are microprocessors. One seems to be connected to a B772L bipolar transistor and the other, through an optoisolator, to a 2N60 MOSFET. I suspect the B772L may be the crowbar.

If someone with more knowledge of switching power supplies disagrees with me please let me know before I go any further.


----------



## rfengineers (Jun 2, 2008)

I was down at my local Northern Tool store this morning looking at the toys and I found this:

http://www.battery-rechargeable-charger.com/vector-VEC1097A-car-battery-charger.html

It's a 30 Amp 12-Volt battery charger/conditioner. It also appears to use switching power supply technology. That means it "should" be possible to run it from 100-to-150 (or so) Volts DC. If so, this should work in conjunction with a 12V accessory battery and eliminate the need for a DC-to-DC converter.

Comments??


----------



## rfengineers (Jun 2, 2008)

I've been working on the Thermaltake 450 again. The B772L near the output terminals turned out to be the regulator pass transistor for the fans. This sure would be a lot easier with a schematic! Is anyone else still investigating the over Voltage problem?

As for the smart charger I found at Northern Tools the other day, I found it on-line at Lowes for $75, so I ordered one. Has anyone played with one of these before?


----------



## Dogbert (Jul 23, 2008)

Yeah, I have been working on the 450W problem - can't make heads or tails of where the overvoltage section is
Soon as I got something worth posting.... Asking other people about the working electronics on switchmodes in general...


----------



## rsandberg (May 15, 2008)

On the subject of over voltage shutdown...

I found this http://www.ifwtech.co.uk/g3sek/smps/smps.htm#DL2YEO

Apparently the "radio" and "amp" guys do this as well, but for a different reasons.

BTW some googling for "13.8 switch mode power supply" returns a bunch of cheap high amp options that might fit our needs.

Keep up the good work! I am very interested in this project.

Rick


----------



## rfengineers (Jun 2, 2008)

rsandberg said:


> On the subject of over voltage shutdown...
> I found this http://www.ifwtech.co.uk/g3sek/smps/smps.htm#DL2YEO
> Rick


Thanks Rick, that link helped me understand switching power supplies a little better.

I believe pin 15 of this chip is what causes overvoltage shutdown:

http://www.rfsoftware.com/DIY/OverVoltage.JPG

The datasheet for the pwm chip is here:

http://www.rfsoftware.com/DIY/CM6800.pdf

The output voltage should be going through a divider and placing a scaled down value on pin 15 of the CM6800. If that value exceed 2.75 Volts the system will shut down. The value must fall below 2.5 Volts to reset the system.

UNFORTUNATELY, while trying to test this theory I had a small mishap, see:

http://www.rfsoftware.com/DIY/smoke1.JPG

and

http://www.rfsoftware.com/DIY/smoke2.JPG

Since the "magic smoke" has now left my test unit I will be unable to do anymore experimenting.

However, Lowes just called and said that my new battery charger has arrived!


----------



## e_canuck (May 8, 2008)

I had an instructor once who told us that all electronic components are packed with "magic smoke" inside. That's how they work. If you let the smoke escape, they do'nt work anymore.

DP


----------



## KiwiEV (Jul 26, 2007)

e_canuck said:


> I had an instructor once who told us that all electronic components are packed with "magic smoke" inside. That's how they work. If you let the smoke escape, they do'nt work anymore.
> 
> DP


LOL
Ahh. that explains why my previous PC stopped working


----------



## KiwiEV (Jul 26, 2007)

Dogbert said:


> Rfengineers,
> I see where you're going with the R34 + R39. I would have tried it but I don't have any low ohm pots on hand. (When is the 24hr Jaycar when you want it?!)
> 
> You were on the right track with R50. I put a multiturn pot across R50 -
> ...


Being in the middle of Winter with a dead accessories battery, an output of 13.6 volts would do me fine. Could you (or anyone) give instructions on what resistor/thing to place across what circuit location to achieve that stable voltage? I'm kinda desperate now as I have less than 5 minutes of headlight/brakepump time before my accessories battery dies!


----------



## rfengineers (Jun 2, 2008)

KiwiEV said:


> Being in the middle of Winter with a dead accessories battery, an output of 13.6 volts would do me fine. Could you (or anyone) give instructions on what resistor/thing to place across what circuit location to achieve that stable voltage? I'm kinda desperate now as I have less than 5 minutes of headlight/brakepump time before my accessories battery dies!


If you remove R34 and solder two wires in its place you can bring them out to a potentiometer. Use about a 5k-ohm pot.

Here is a view of R34: http://www.rfsoftware.com/DIY/Regulator-closeup.JPG

R34 is the one near the silkscreen label "R34" The chip resistor is labeled "100".

Here is a view of R34 removed and a pot installed: http://www.rfsoftware.com/DIY/smoke1.JPG AND http://www.rfsoftware.com/DIY/smoke2.JPG

You should be able to increase the voltage to 13 or 13.5 before the overvoltage kicks in. That should be with the pot set to around 2500-to-2800 ohms. BE CAREFUL!!!!!! See images smoke1 & 2 above to understand why you need to be careful.

I hope someone is working on the overvoltage control issue. See: http://www.rfsoftware.com/DIY/OverVoltage.JPG AND http://www.rfsoftware.com/DIY/CM6800.pdf for more information.

I need to drive down to Melbourne to pick up my WarP-9 motor this morning. I will be back this afternoon if you have any more questions.

Good Luck


----------



## KiwiEV (Jul 26, 2007)

rfengineers said:


> If you remove R34 and solder two wires in its place you can bring them out to a potentiometer. Use about a 5k-ohm pot.
> 
> Here is a view of R34: http://www.rfsoftware.com/DIY/Regulator-closeup.JPG
> 
> ...


Ok, thanks for that. I'll have a go at it this weekend. Let's hope I don't blow it up.

Edit: Crikey, I've had a good look at that circuit board and man is it TINY! My fumbling sausage-fingers will make a real mess of it so be prepared for the Scorched Earth circuit photos!


----------



## Dogbert (Jul 23, 2008)

rfengineers said:


> Rather than reducing the value of R50 as we are now doing, do you think it would be better (more stable?) to increase the value of R34+R39? I am not sure exactly how the TL431 operates but the data sheet examples show a pot in that location rather than across the anode and reference pins.
> 
> It would be fairly simple to remove the 10-ohm, r34 resistor and insert a pot in its place.
> 
> I should be able to do that a little later this afternoon.


Rfengineers,
wondering why you think it is better to go with r34+r39 rather than r50? Why would one be more stable than the other? Is it because R50 draggs the entire voltage divider down where R39+R40 control only the feedback? Please inform a nOOb!



rfengineers said:


> I believe pin 15 of this chip is what causes overvoltage shutdown:
> 
> The output voltage should be going through a divider and placing a scaled down value on pin 15 of the CM6800. If that value exceed 2.75 Volts the system will shut down. The value must fall below 2.5 Volts to reset the system.
> 
> UNFORTUNATELY, while trying to test this theory I had a small mishap


BUGGER on the mishap!

With that one the PFC OUT goes low until reset. PWM remains working (according to text). I'm just soldering a couple leads to pins 15 (Vfb) and 10 (GND) to get ready for a pot... If you have any ideas / recommendations let me know!

What did you do to release the "Magic Smoke" when testing the OVP mod?
I don't replicate the same result.


----------



## Madmac (Mar 14, 2008)

Not having a power supply to look at I would offer the following completely blindly.

For a power supply of this rating I would expect the over current limit and over voltage to be completely separate from the PWM controller except for shutting it down. The best way to do that would be with the SS or slow start pin. On shut down the DC rail may bounce but the PFC section of the controller is protected against an over volt.


Madmac


----------



## rfengineers (Jun 2, 2008)

Dogbert said:


> Rfengineers,
> wondering why you think it is better to go with r34+r39 rather than r50? Why would one be more stable than the other? Is it because R50 draggs the entire voltage divider down where R39+R40 control only the feedback? Please inform a nOOb!


I was concerned about connecting the anode to the reference input. 



Dogbert said:


> What did you do to release the "Magic Smoke" when testing the OVP mod?
> I don't replicate the same result.


It was a dumb beginners mistake. I know better, but was not thinking (I used to teach this stuff in the Navy). The reference for the CM6800 floats. I connected my scope probe reference to the PWM's floating ground without putting the isolation plug on my scope's power cord. The result was very exciting.


----------



## rfengineers (Jun 2, 2008)

I've removed the PWM board from the main circuit board. Here are some pictures and the schematic I came up with.

http://www.rfsoftware.com/DIY/Image4.png
http://www.rfsoftware.com/DIY/PWM-Back.png
http://www.rfsoftware.com/DIY/PWM-Schematic.JPG

Feel free to ask me to take more pictures or trace paths. Unfortunately, I am no longer able to power up the unit and take measurements.


----------



## Dogbert (Jul 23, 2008)

Rfengineers, can you please give the whole board a scrub with some metho and an old toothbrush and take another photo of it (having trouble seeing the top tracks with the glare and bottom from burn).

You have C5 and C8 in your diagram - where are they on the board? 
Is C8 the top of the row of SMD's between the legs of the CM6800? (no porn pun intended)
Also, according to the text, C5+C8 should end up at GND (pin 10)??!!
If you happen to find the voltage divider resistors between pin15+pin10 (GND) before I do, please shout it out! 

Thanku!


----------



## rfengineers (Jun 2, 2008)

Dogbert said:


> Rfengineers, can you please give the whole board a scrub with some metho and an old toothbrush and take another photo of it (having trouble seeing the top tracks with the glare and bottom from burn).


I will get the new pictures done a little later today. BTW, call me Joe.


Dogbert said:


> You have C5 and C8 in your diagram - where are they on the board?


See the closeup here: http://www.rfsoftware.com/DIY/closeup1.png


Dogbert said:


> Also, according to the text, C5+C8 should end up at GND (pin 10)??!!


C8 seems to go to pin 14, I need to dig a little deeper to see where else it goes. I'll get back to you on this.

Joe


----------



## rfengineers (Jun 2, 2008)

Dogbert said:


> Rfengineers, can you please give the whole board a scrub with some metho and an old toothbrush and take another photo of it (having trouble seeing the top tracks with the glare and bottom from burn).


Here is the back of the PWM board. I cropped, but did not shrink, the picture, so it's big.

http://www.rfsoftware.com/DIY/PWM-Back-Closeup.png

Would you also like a higher res picture of the main board?

Joe


----------



## KiwiEV (Jul 26, 2007)

So far so good. The unit is now dismantled and sitting on the desk. 
I've plugged one of the 8-pin cables into the unit and fired it all up on 230v AC with no worries. I connected all 3 yellow leads together and connected all 5 black leads together with a steady 12.04 volts coming out of that lead. Anyone see anything wrong with doing that?

Tomorrow I'll get a 0-5kohm potentiometer and attach it across R34 if I can solder it without destroying the circuit board. 
Hey Joe, how did you release your magic smoke exactly? Was it doing what I'm about to do? Are you able to offer any advice to avoid me releasing my magic smoke too?

Regards,
One curious but worried Kiwi.


----------



## rfengineers (Jun 2, 2008)

KiwiEV said:


> Tomorrow I'll get a 0-5kohm potentiometer and attach it across R34 if I can solder it without destroying the circuit board.
> Hey Joe, how did you release your magic smoke exactly? Was it doing what I'm about to do? Are you able to offer any advice to avoid me releasing my magic smoke too?


I broke one of the basic rules. I hooked up my test equipment to read something that was not referenced to chassis ground without isolating the measuring device from the common ground.

To be specific, I connected my oscilloscope probe reference lead to the PWM circuit board "ground" without putting the isolation plug on the power lead of the 'scope. 

Since you will not be working on the PSU while it is powered on you should be OK.

Good Luck,

Joe


----------



## KiwiEV (Jul 26, 2007)

So far so good everyone. I've replaced R34 with a 2700 ohm resistor and I'm getting 13.3 volts out of it which is good enough for me.
One question though, when connecting the power-in cable to the battery pack, which colour is which? The colours in the power cord are white and black. At the PSU end, the colours change via the plug in the back of the PSU:
Cord: white - PSU: blue
Cord: black - PSU: brown
Cord: green - PSU: green

The green is earth obviously, but which would be the + and - out of the other two? 
We're almost there...


----------



## KiwiEV (Jul 26, 2007)

I've struck a problem. I've managed to hook the unit up on the car's voltage (155 volts) and I fired it up ok with a nice 13.35 volts coming out of it. 
Problem is, whenever I apply too much load it shuts down and won't restart unless I remove the input and wait a few seconds. I find that any more than around 15 amps kills it.
I tried connecting ALL the yellows and ALL the blacks together but the problem remains.

The headlights always trip it but everything else is ok. The wipers are alright, as long as I don't press the brake (and activate the vacuum pump) at the same time.

Ugh, so very close... I gave up after an hour or so. I'm one frustrated kiwi right now. I need a drink.


----------



## Madmac (Mar 14, 2008)

Go back 2 steps. Remove the voltage mod, and running on battery pack.

Then run the PSU at 12 volts in the car from the mains, without the battery in place, check it runs OK with head lights etc.Obviously if that does not work you have a faulty unit. If it runs OK then connect the battery and see if it is still OK, if this causes a problem then you will need a diode in the ouput. 

Up the voltage to say 12.8 / 12.9 volts and also running from the mains check it in the car again.

If it works OK then the problem is probably the switch mode regulator having overshoot in the output when a large load is suddenly added and it over responds to the dip in output. 

Until someone works out the protection circuit you will have to turn up the voltage as high as you can without tripping the over volt protection.

Couple more blind suggestions that may have been already looked at... added opamp or comparators not normally used in a low current PSU, from the photo's it does not look like the SS pin is used to shut down the PWM section so other easy way is either pin 3 or 9, the current (feedback PFC) and over current comparator (PWM) inputs. 

It is also worth checking that the CM6800 VCC pin does not go above 17.9V when the output is increased as this will shut the chip down. Supplying this from a separate winding so that it acts as a over volt shut down is a cheap solution.

Madmac


----------



## KiwiEV (Jul 26, 2007)

Alllright, I'm de-stressed now. I've had a glass of cognac and I'm all set for another go at the PSU. Thanks for the tip, I'll try at a lower voltage. Unfortunately the little circuity-thing at R34 disintegrated when I removed it so I'll have to just keep going lower voltage by voltage.
I'm not beat yet!


----------



## Dogbert (Jul 23, 2008)

Madmac said:


> Couple more blind suggestions that may have been already looked at... added opamp or comparators not normally used in a low current PSU, from the photo's it does not look like the SS pin is used to shut down the PWM section so other easy way is either pin 3 or 9, the current (feedback PFC) and over current comparator (PWM) inputs.
> Madmac


I'll look into that. I have a setup at the moment that i'm about to try a trim-pot or two....



Madmac said:


> It is also worth checking that the CM6800 VCC pin does not go above 17.9V when the output is increased as this will shut the chip down. Supplying this from a separate winding so that it acts as a over volt shut down is a cheap solution.
> Madmac


It dosen't. I've had the R50 mod on for a while, and even with the output voltage at 13.7 (just on the edge of shutdown) the VCC pin reads 15.5v to the chips' GND.

about to check the volts on pin 15 (Vfb)....

[EDIT]: Ok, I'm gonna look more into your theory Madmac. 
The voltage at Vfb (pin 15) stayed at a constant 2.52v as I increased the output voltage with the R50 trim-pot. Then, once it shutdown it dropped to 1.32v, but at no time did it go over the 2.75v that the text said would cause shutdown.


----------



## Madmac (Mar 14, 2008)

> The voltage at Vfb (pin 15) stayed at a constant 2.52v as I increased the output voltage with the R50 trim-pot. Then, once it shutdown it dropped to 1.32v, but at no time did it go over the 2.75v that the text said would cause shutdown.


That is what you would expect, it is inside the feedback loop. The loop works to keep that voltage the same as the other input to the amplifier, the internal 2.5 volt reference. The over volt on this section is if the voltage of the DC rail rises too quickly for the feedback loop it will block the drive to the output FET. Remember the function of the PFC section is to make the current drawn from the mains directly proportional to line voltage....... as required by regulations these days for PSU's over 75 watts.

Note that this is the PFC section and the over volt and over current will shut down the PWM section quickly (as this is driving the output). The PFC section just regulates the DC rail before the PWM.

Most likely is pin 9, the DC I Limit on the PWM section, follow it back and see if there are any other IC's around there, if so sketch out circuit.


Dogbert.. is there any chance you can take a photo showing the heatsink arrangements. I am thinking of mounting onto metal plate then on to water cooled base plate. That would leave the power supply upside down. All of the photos to date only show part of the assembly. Cheers
Madmac


----------



## Dogbert (Jul 23, 2008)

rfengineers said:


> I will get the new pictures done a little later today. BTW, call me Joe.
> 
> See the closeup here: http://www.rfsoftware.com/DIY/closeup1.png
> 
> ...


Thanks Joe for pointing those out.
Ok, now I get the C5 +C8.
Btw, call me Brent!



rfengineers said:


> Here is the back of the PWM board. I cropped, but did not shrink, the picture, so it's big.
> 
> http://www.rfsoftware.com/DIY/PWM-Back-Closeup.png
> 
> ...


Cool, thanks for that closeup - much better! Yes please! A higher res pic of the mainboard would be great! (and I won't risk the burn spots from my magnifying glass!)


----------



## Dogbert (Jul 23, 2008)

Madmac said:


> Dogbert.. is there any chance you can take a photo showing the heatsink arrangements. I am thinking of mounting onto metal plate then on to water cooled base plate. That would leave the power supply upside down. All of the photos to date only show part of the assembly. Cheers
> Madmac


Here you go.
http://i383.photobucket.com/albums/oo271/dogbert_bucket/PHTO0014.jpg
http://i383.photobucket.com/albums/oo271/dogbert_bucket/PHTO0016.jpg

Apologies for the crap lighting - My camera was electrical taped to my RC plane when the plane nose-dived.
It hasn't been the same since. (no, didn't recover the video)


----------



## rfengineers (Jun 2, 2008)

Dogbert said:


> ... A higher res pic of the mainboard would be great! (and I won't risk the burn spots from my magnifying glass!)


I have placed high-res pictures (nearly 3Mb each) of the back of the main board here:

http://www.rfsoftware.com/DIY/MainBoardBack-1.JPG
http://www.rfsoftware.com/DIY/MainBoardBack-2.JPG
http://www.rfsoftware.com/DIY/MainBoardBack-3.JPG
http://www.rfsoftware.com/DIY/MainBoardBack-4.JPG
http://www.rfsoftware.com/DIY/MainBoardBack-5.JPG
http://www.rfsoftware.com/DIY/MainBoardBack-6.JPG

Joe


----------



## Dogbert (Jul 23, 2008)

WOW! cool! Thankyou Joe!

Btw everyone - Bugger it, I'm gonna email thermaltake and see what response I get from their Tech department. (I won't tell 'em what it's for of course)


----------



## etischer (Jun 16, 2008)

The vacuum pump probably has a big inrush current, and it's an inductive load. Perhaps a big 16v capacitor might help, is your power supply connected to the battery too? 




KiwiEV said:


> I've struck a problem. I've managed to hook the unit up on the car's voltage (155 volts) and I fired it up ok with a nice 13.35 volts coming out of it.
> Problem is, whenever I apply too much load it shuts down and won't restart unless I remove the input and wait a few seconds. I find that any more than around 15 amps kills it.
> I tried connecting ALL the yellows and ALL the blacks together but the problem remains.
> 
> ...


----------



## KiwiEV (Jul 26, 2007)

I tried a couple of methods yesterday, both with or without the battery attached and I had the same problem of it going dead. I'm about to try again today with a lower output voltage to see if it happens again. 
That 13.4 volts was brilliant though, the wipers and the vacuum pump were going flat out - they were loving the higher voltage. They just don't have the same enthusiasm when connected to a standard battery. I need a whip. 

Anyway, I'll give the car a Deluxe Full Service (AKA top up the battery water) and I'll have another go.


----------



## KiwiEV (Jul 26, 2007)

One thing I've found is that once the 144v has been removed, the PSU continues to "run", backfeeding through the 12v battery. 
Now my plan is to use a tiny accessories battery for effectively _starting_ the car and PSU, maybe around 4 Ah so I can tuck it away somewhere. 
Problem is, that backfeeding draws around 0.2 amps which would drain a tiny "starter" accessories battery (maybe around 4 ah) down in a day. 
I don't really want to have to flick a switch on the dashboard every time I get out of the car to stop the PSU backfeeding as I'd probably forget to do it all the time. My wife _certainly_ would.  
If I got rid of the accessories battery, I'd have no way to click the main contactor/start the car, and I'd lose my clock and stereo station presets.

Any suggestions?


----------



## e_canuck (May 8, 2008)

Hey Kiwi.

I am not an engineer, but...

A quick question or two. You stated that your accessory battery is sick. Does it have and keep a full charge?

Instinct tells me that when the pump turns on, the system voltage goes low and the under voltage protection kick in.

Sometime batteries are used as a dampener for load changes in a system.
If after charging you ca'nt get a good voltage maybe try another battery.

DP


----------



## etischer (Jun 16, 2008)

Couldn't you just put a relay in to connect the PSU to the Battery when the key is on? You could also put a diode in so the PSU can supply the battery, but the battery cannot supply the PSU. 



KiwiEV said:


> One thing I've found is that once the 144v has been removed, the PSU continues to "run", backfeeding through the 12v battery.
> Now my plan is to use a tiny accessories battery for effectively _starting_ the car and PSU, maybe around 4 Ah so I can tuck it away somewhere.
> Problem is, that backfeeding draws around 0.2 amps which would drain a tiny "starter" accessories battery (maybe around 4 ah) down in a day.
> I don't really want to have to flick a switch on the dashboard every time I get out of the car to stop the PSU backfeeding as I'd probably forget to do it all the time. My wife _certainly_ would.
> ...


----------



## KiwiEV (Jul 26, 2007)

Yeah the accessories battery is sick, but the problem remains whether a battery is connected in parallel with the PSU or not.
I was thinking of using a relay but I'm not sure if it would work as (someone correct me if I'm wrong) the relay would backfeed also? Would a physical relay like a solenoid do the trick instead? 
I could be barking up the wrong lamp post though so please point out any flaws in my logic.


----------



## e_canuck (May 8, 2008)

Backfeed...Gotcha.

Took me a while to understand that the damn thing w'ont shutoff.

A relay will work. It as to be powered from the ignition so it get's power only with the contact is on.

DP


----------



## Dogbert (Jul 23, 2008)

KiwiEV said:


> One thing I've found is that once the 144v has been removed, the PSU continues to "run", backfeeding through the 12v battery.
> Now my plan is to use a tiny accessories battery for effectively _starting_ the car and PSU, maybe around 4 Ah so I can tuck it away somewhere.
> Problem is, that backfeeding draws around 0.2 amps which would drain a tiny "starter" accessories battery (maybe around 4 ah) down in a day.
> I don't really want to have to flick a switch on the dashboard every time I get out of the car to stop the PSU backfeeding as I'd probably forget to do it all the time. My wife _certainly_ would.
> ...





Dogbert said:


> Yes true, we do need 14.2 or preferably 14.4v if we use a high power diode to stop back-feed when the PSU gets turned off.
> I think one would be needed. When I hooked up a battery with 13.6v and turned off the PSU, it then turned ALL the lights on at the front (I'm only running off one line - one light) even though it was off. There would have been some wasted current at that time. I'll do another run and try to measure it.
> ALSO - even at 13.6 The PSU could not be switched on / powered up with the battery attached on the output. It had to be connected after the PSU was running ok. A diode MAY fix this - I'll try it out...


Gav, I first thought of having a relay energized by the 12v of the 450W and if it stops it will drop out and swap over to a 17AH emergency SLA (that would be kept topped up with a booster and a solar style charger/regulator feeding of the 450W).
So, If you don't want to do any voltage mods and make everything a bit more complex then that's my 2c! It may need some other wiring/relay for protection when the car is shut down, but I'm not sure.

Once we work out this mod then all you will need is a BIG diode (I'm just gonna use a 35A bridge rectifier, but only one or two diodes in it - connect PSU+ to both AC's on the bridge, then + on the bridge is your +out).


----------



## lazzer408 (May 18, 2008)

Hi guys!

Just checking in. Sorry to vanish for so long. I bought two cars to fix up to sell to make a quick buck. $2000 profit off one of them.  I -almost- kept it over my current car but I sold it instead. I should have kept it because a few days later I grenaded my engine.  I got a junkyard engine back in and it's back on the road. So between 3 cars worth of auto-drama I got pretty far behind. I'll be able to catch up on all these other projects now.

I'll have to go through the thread and see where everyone is at. I'll have a chance later tonight.

I skimmed through and saw something about a backfeeding issue. Is it just keeping the lights on? It's not keeping the unit powered I know that much. The secondary diodes should block any harm to the psu. Check with an amp meter and see if it's actually drawing a load off the 12v side when it's off. If not, snip off the original lights and put your own led/resistor off the pfc cap (The ~400v one). A 20k should do it.


----------



## Madmac (Mar 14, 2008)

With the power supply off and connected to the battery it will draw current. Firstly the LEDs will remain on and secondly the feed back and over voltage / current circuitry will be drawing current may be up to a few 10's of milliAmps.

It is unlikely to be under voltage shutdown as this is normally a lock out on the power input side of a switch mode. Most systems do not worry about the output going low. If the current drawn trips the limit then it will reduce the output anyway. The power supply should be good for transient response as a video chip GPU can draw extra 10's of amps very quickly (at its core voltage)

A low voltage drop diode in line with the output of the power supply will stop the battery being drained. It does have the disadvantage of reducing the power supply voltage by Vf of the diode. 

Keeping the battery means it will provide a 'stiffening' when a surge load is added.

Madmac


----------



## lazzer408 (May 18, 2008)

Kiwi (and others) pull the primary bridge rectifier and connect your pack voltage to the + and - terminals. Don't connect it to your pack backwards because you have no reverse polarity protection.


----------



## lazzer408 (May 18, 2008)

Madmac said:


> feed back and over voltage / current circuitry will be drawing current may be up to a few 10's of milliAmps.


What is the IC using for the reference voltage? In other words, what is it compairing the sense (feedback) voltage too? Can we raise that?


----------



## Dogbert (Jul 23, 2008)

Madmac said:


> Note that this is the PFC section and the over volt and over current will shut down the PWM section quickly (as this is driving the output). The PFC section just regulates the DC rail before the PWM.
> 
> Most likely is pin 9, the DC I Limit on the PWM section, follow it back and see if there are any other IC's around there, if so sketch out circuit.


I don't think the above will work Madmac. The Vfb-pin limiter was meant to shut down the PFC section but the PWM was meant to run as normal (according to the text). I will check pin 9, but it is meant to be a cycle by cycle feedback (see "PWM current limit" page 12) to limit the current in case of a short (and then continue as normal soon as the short is removed). We arn't pulling any power at all atm, but raising the voltage still shuts down the output permanently until reset.



Madmac said:


> With the power supply off and connected to the battery it will draw current. Firstly the LEDs will remain on and secondly the feed back and over voltage / current circuitry will be drawing current may be up to a few 10's of milliAmps.





lazzer408 said:


> What is the IC using for the reference voltage? In other words, what is it compairing the sense (feedback) voltage too? Can we raise that?


Madmac, were you refering to the back-feed of power to the whole circuit in general when the power supply is turned off?
Lazzer, good idea. I think. 

Everyone, we should be focusing on the over-voltage cutout atm. 
I'm gonna sketch out as much of the PCB's (chip one and below that as well). Please can everyone who has voided their warranties please do the same so we can narrow this down!

NOTE: MSY computers in Melbourne, Australia have stopped stocking the 250w. I was gonna mod one of each.

EDIT: Just checked the voltage at pin-9. It stayed constant at 0.05v all through the voltage raise and even after overvolt shutdown.
Statement - the red light turns off when the shutdown occours. Question - can we trace that back??!!
Maybe the light is just an indicator for a certain section shutting down. Finding the FET or whatever that does this can help.


----------



## Madmac (Mar 14, 2008)

> Lazzer, good idea. I think.


Raising the Vref that is inside the chip is the same as the mod to adjusting the voltage on the other side of the feedback opamp. The power supply works to keep the voltage reference and the feedback voltage from the output voltage the same. You can vary either to raise or lower the voltage as long as the stability of the loop is not affected.

As I understand the overvolt problem it latches until the power supply is adjusted back and the power cycled.
To do this some means of shutting down either the PFC or PWM section is needed. Normally you shut down the PWM section so that it does not continue to run from the DC rail capacitors damaging external circuits.

To shut down a control input must be used or the drive to the output FETs stopped or the CM6800 power supply interrupted. Using the current limit pin is a common choice as it shuts off the drive straight away (not getting confused with the current feedback pin). Taking that pin above 1 volt shuts the PWM section off. As you say it is not being used then another method is doing the job. Drawing the circuit looks like it will be the only way. Possible other pins are the VDC pin6, SS pin 5 (not connected). Look at the block diagram of the CM6800 to see what pins can turn off the output.



> Madmac, were you referring to the back-feed of power to the whole circuit in general when the power supply is turned off?


The circuitry on the output side of the optoisolators is powered from the 12 volt output. From the photos it looks like a couple of optos and opamps / comparators. These will be powered by the battery and slowly drain it unless a diode or relay is used to isolate. The primary side is isolated from the output by the transformer and opto's.

Madmac


----------



## lazzer408 (May 18, 2008)

My eyes hurt. 

2 things need to be accomplished.

#1 The voltage feedback opto-iso (u5) needs it's 'led side' voltage lowered.
(semi-solved)
#2 ovp (over-voltage protection), if any, needs to be tracked down.

How does the psu handle ov? Does the cm6800 pfc ic monitor it directly or is that ic signaled by something else? Usually the PFC side of these things is in it's own world and could care less what the secondary is doing.

On the secondary we have a m07743a1f IC. If I had to bet, I'd say it's a quad op-amp or comparator. We already know it has the ability to control the on-off state of the psu because the ps-on signal drives it. All it needs to do is monitor the output and pull the ps-on signal low if the output voltage gets above a set value. Does it's output drive u3 (opto-iso)? And what is u10 (opto) for? Turn-on/shutdown?


----------



## Madmac (Mar 14, 2008)

As the power supply is controlled from an external input I would guess that the second opto controls the primary side. A volt meter on the diode side and see what happens at start up and over volt.

As a matter of interest does the DC rail voltage fall when the overvolt occurs?

Madmac


----------



## lazzer408 (May 18, 2008)

Madmac said:


> As the power supply is controlled from an external input I would guess that the second opto controls the primary side. A volt meter on the diode side and see what happens at start up and over volt.
> 
> As a matter of interest does the DC rail voltage fall when the overvolt occurs?
> 
> Madmac


Which rail? Primary DC rail?

Probe the pins on the m07743a1f. I'm sure one of them is watching the secondary output.

Anyone have a data sheet on that IC? I can't find one.


----------



## Madmac (Mar 14, 2008)

Should have read

As a matter of interest does the PFC DC rail voltage fall when the overvolt occurs.

Madmac


----------



## KiwiEV (Jul 26, 2007)

Success! 









I installed the PSU into a lunchbox with some gaping ventilation holes in the front and back and mounted it into the car!









There it is in the corner where the battery used to be. I'm currently trialling it in place of the battery. It's permanently running and uses around 11 watts (including the ventilation fans). This way I've bypassed the battery completely and if it works ok over the next few days then I'll use this method from here on.









As you can see, I've put a 0-5kohm pot on the lid for fine-tuning the voltage. The absolute highest I can put it is 12.70 volts without tripping while all the electrics are running.

My "scientific" test included having the following things running at the same time:
Headlights (on highbeam) including Taillights
Vacuum Pump and Brake Lights
Fan (full speed)
Reverse Lights
Window Wipers (full speed)
Radio
Cigarette Lighter
Turning them all on at the same time was like playing a fast game of twister but it worked. 12.80 volts will _just_ trip with all of the above running but 12.70 can handle it.

Ugh, I just realised I forgot the indicators in that test. Oh well, we'll see how it goes, at least I can tweak the voltage easily with the potentiometer on the lid. 

Thanks everyone especially Lazzer and Joe for helping me with this. I'll let everyone know if it works out ok or what problems I encounter.


----------



## DVR (Apr 10, 2008)

Hi guys, While I know basically nothing about electronics, this thread is being followed by some guys on the AEVA forum in Australia. 1 bloke suggested something that I thought I would pass on in case it helps.

Quote "_Fit a 0.02ohm (50W) resistor in series with the output from the SMPS so aux battery picks up peak loads. Voltage drop will be 1V at 45A of course, Ok you will be at 12.8V rather than 13.8V but you will rarely use all 45A. 
You may get away with 0.01ohm. Choice of cable can supply this.

As I mentioned in in earlier post, computer type SMPS have this shutdown nature by design.







" _ Unquote

I hope this helps.


----------



## chamilun (Jun 17, 2008)

Gav,
congratulations!

No one puts theory into practice quicker than you. It will be interesting to see how things go.

Why not keep an accessories battery as well? redundancy would seem to be a good thing.


----------



## rfengineers (Jun 2, 2008)

DVR said:


> "_Fit a 0.02ohm (50W) resistor in series with the output from the SMPS so aux battery picks up peak loads. Voltage drop will be 1V at 45A of course, Ok you will be at 12.8V rather than 13.8V but you will rarely use all 45A.
> You may get away with 0.01ohm. Choice of cable can supply this.
> 
> As I mentioned in in earlier post, computer type SMPS have this shutdown nature by design.
> ...


An interesting Idea! I wonder if a fuseable link would serve this function?


----------



## KiwiEV (Jul 26, 2007)

Congratulations Lazzer, you have one of these on it's way to you:









Joe, if you want one too I'd be happy to but it'll have to wait til next Payday!


----------



## Dogbert (Jul 23, 2008)

DVR said:


> Hi guys, While I know basically nothing about electronics, this thread is being followed by some guys on the AEVA forum in Australia. 1 bloke suggested something that I thought I would pass on in case it helps.


I'm part of the AEVA in Melbourne, Australia, and I told them about this!
Can't believe that I didn't check the forums! 
What section did you see it in DVR?


----------



## DVR (Apr 10, 2008)

Here's the link to the AEVA forum that mentions this thread.
http://www.aeva.asn.au/forums/forum_posts.asp?TID=529&PID=4461#4461

Guys a couple of quick questions.
If you run a 450W unit at 12.70 volts in conjunction with a battery, will the battery get charged or will it slowly run down?

Also could Gav's over volt shut down problem be caused by the fact that his battery is stuffed? It may not have the grunt left in it to cover the gap that the PSU cant provide and would also explain why he get's the same result with oe without the battery.


----------



## Dogbert (Jul 23, 2008)

Hey everyone, This may help...
To understand this better, have a look at the following picture Joe put up...
http://www.rfsoftware.com/DIY/MainBoardBack-1.JPG
at
http://www.diyelectriccar.com/forums/showpost.php?p=67821&postcount=178
Look at the row of pin holes where the CM6800 add-on board joins to.
I jotted down all the voltages on the pins of the CM6800 add-on board through all states of raising the voltage.
These are WRT the CM6800 GND (pin 10). You can use the pin with the square around it in the photo to understand the circles on the top of my diagram. Also note: There are 11 pins in my diagram where the add-on board only has 10. I'm not sure as yet what the extra pin is near C50 (haven't had a chance to look)....
Some PCB diagram scribbles coming soon as well....


----------



## DVR (Apr 10, 2008)

Guys I found this seller on ebay EParts 138
The price of some of their smps' make me wonder if all this is worth it!!
Specifically
This one is 350W 25.3A $68AU delivered.
This one is 400W 29A $81AU delivered.
This one is 1000W 72A $236AU delivered.

All have these specs.

*Power Supply Specifications :*


Suitable for Radio Power Amp. project. 
Input voltag : 110 / 220V Manual Switch
+ / - 10% adjustable output voltage 
Daul fan design
Thermal control cooling fan
High Efficiency, Low Temperature, Small Size
Built-in EMI Filter 
Over Load and Short Circuit Protection
Over Voltage Protection
Auto-recovery after protection
Interesting to note that they Auto recover after a fault.
All this and no modding.

Thoughts?


----------



## Dogbert (Jul 23, 2008)

Looks very good!
The only thing I'd be concerned about is if it can take pack voltage DC direct in. With the one we have been fiddling with it is direct rectified and then is DC all the way through. The Ebay one would have to be the same.

How could we tell if it could?

Other than that - Very good find!

I might grab one and then disect it for everyone to give it the "verbal testing"


----------



## rsandberg (May 15, 2008)

I have been told by a couple dudes (that know what they are doing - unlike me) that you can shove DC right in the AC input plug.

This assumes that the power supply is of the SWITCHED MODE variety (NOT Linear).

The reason is that the first thing a switch mode PS does is rectify and filter the incoming AC. That rectified (now DC) voltage is then chopped up into little bits and sent through the "switching" part of the amplifier.

The PS input rectifier does not care if you pass DC through it.

I was proposing this same idea in an earlier reply, but did not want to offend anybody because of all the hard work invested.

If you search ebay for "13.8" and "power supply", there are a bunch of options that may be suitable. I am waiting to see how much current I will need before I jump in, but I may buy one of the cheapies just to play with. For example the DuraCom LP-14 can be had for $20.

Good Luck,
Rick


----------



## lazzer408 (May 18, 2008)

rsandberg said:


> I have been told by a couple dudes (that know what they are doing - unlike me) that you can shove DC right in the AC input plug.


Yes, but you risk blowing the rectifier because your only using half the diodes.  Take the extra step and bypass the rectifier.


----------



## booksix (Aug 26, 2008)

Is there any update on the 650's (anyone wire one up)? How about some road time for any of the 3 units?


----------



## KiwiEV (Jul 26, 2007)

booksix said:


> Is there any update on the 650's (anyone wire one up)? How about some road time for any of the 3 units?


So far so good this end. The 450W unit's performing excellently one week on. It's saved my wife from going mad with a constantly flat accessories battery.


----------



## booksix (Aug 26, 2008)

Nice! That's really encouraging. So what gauge wire connects this thing to the traction pack and the acc battery? and, maybe I missed it, but was there any detailed instructions written for the 450 after your mod?


----------



## ClintK (Apr 27, 2008)

booksix said:


> Nice! That's really encouraging. So what gauge wire connects this thing to the traction pack and the acc battery? and, maybe I missed it, but was there any detailed instructions written for the 450 after your mod?


Great work guys! And I second that question! When is the wiki going up with step by step explanations and pictures (please please please)?

Gav, if your setup of no battery/modified PC power supply/always on works out, then I'd like to do the same for my conversion (and it sounds like its working!).

DVR mentioned another potential power supply to try out. Is anyone looking more into that or should I keep my focus on the Thermaltake 450 (only 2 left on Amazon)?

Thanks!


----------



## KiwiEV (Jul 26, 2007)

I'll get around to adding it into the wiki within the next couple of days, for the timebeing, I've put some basic instructions on my site: http://www.kiwiev.com/Life with the Tredia.htm
It's at the bottom in "September". I must organise that webpage sometime too. Starting to get cluttered.

The DC converter's doing a great job. It's nice to be able to zip to the shops without tripping over the 12v battery leads for the accessories battery. Once I forgot to detach the accessories battery charger. It has extended leads (about 5 metres) and I started reversing. When I looked back I noticed a giant umbilical cord stretching across the lawn and slammed on the brakes! Close call!


----------



## booksix (Aug 26, 2008)

ahhahaha!! thats awesome! Glad you caught it before it was too late. Thanks for the instructions as well... I'll be checking them out soon!


----------



## Dogbert (Jul 23, 2008)

DVR said:


> Guys I found this seller on ebay EParts 138
> The price of some of their smps' make me wonder if all this is worth it!!
> Specifically
> This one is 350W 25.3A $68AU delivered.
> ...


I have bought the 400w version! I'll give everyone the verdict when it gets here.


----------



## Madmac (Mar 14, 2008)

From a quick look at the spec the mains input is switched between 120 / 230 volts. This usually means that the internal switcher works off rectified and smoothed 230 volts or approx 320 volts DC. To run on 120 volts the power is fed to the centre of 2 smoothing caps and one side of the bridge rectifier to use it as a capacitor doubler. This will only work on AC.

If it is universal input, usually with PFC, then it will work ok on 120 / 144 volt DC packs.

If it works OK post and let everybody know.

Madmac


----------



## Dogbert (Jul 23, 2008)

Madmac, do you mean that it might only work on it's 240v setting?

I have tried other standard PC PSU's before that have this setting switch to no evail. (except a big POP on the 120v setting)
I also noticed that although some of them ran off 72-120v DC it barely ran. They only gave 7.something V out.

I'll disect it, show everyone the PCB layout and then try modding from there.


----------



## Joel (Jul 29, 2008)

I'm bringing this thread back to life
anything on fixing the thermaltake overvoltage protection?
did anyone try getting those HongKong/ebay 13.8V switching power supplies off ebay to run from DC instead of AC?


----------



## e_canuck (May 8, 2008)

Hi Joel.

You beat me to it by half a day.

Does anyone know if Dogbert ever got is power supply?

His last post and activity is from September.

Thanks all.

DP


----------



## Dogbert (Jul 23, 2008)

Hey everyone! I just got back yesterday from California! One word - FUN!
Got to many VW beetle parts for my trunk to handle (it popped 1/2 the rivets out of the bottom)!

Ok, onto the power supplies - Thremaltake - a radio engineer friend will be taking a look at it next week and he'll look specificly at the OVP.

The China PSU - Great power output! 13.8v stable. I have used it to quick charge big Deep Cycles. It pushes over 20A and then tapers off until charged.
As madmac predicted - it does have the 120/240v switch and he is correct on the internals from what I can see. I will post pictures soon. I will be hooking up as many batteries as i can to do a test 'pack voltage' input on the 240v setting.

Stay tuned!

Dogbert


----------



## Joel (Jul 29, 2008)

yay, i look forward to the news!


----------



## Dogbert (Jul 23, 2008)

Ok, The cheap china PSU - Won't run off DC input. 
I put 120v into it and it still didn't show any signs of firing up.


----------



## Guest (Nov 2, 2008)

Ask an old "Shade Tree Mechanic." 
Chevy allways charged to 13.8 vdc. 
Ford charged to 14.2 vdc. 
Either one worked "FINE" but, above 14.4 the light bulbs suffered from reduced life.


----------



## etischer (Jun 16, 2008)

Maybe there is a filter circuit in there preventing the DC from flowing. Got a pic of the psu? Is there a diode bridge you can connect the dc up to?




Dogbert said:


> Ok, The cheap china PSU - Won't run off DC input.
> I put 120v into it and it still didn't show any signs of firing up.


----------



## etischer (Jun 16, 2008)

Lasser, I've been trying to pm you but it says your box is full, please pm me. 

eric.


----------



## jondoh (Sep 8, 2008)

can this power supply be modified to run off of 72v dc input? If so, how?


----------



## EV59RAG (Oct 6, 2008)

jondoh said:


> can this power supply be modified to run off of 72v dc input? If so, how?



I would like to know this too if this is possible?


----------



## rfengineers (Jun 2, 2008)

jondoh said:


> can this power supply be modified to run off of 72v dc input? If so, how?


I don't know.


----------



## simey_binker (May 13, 2009)

OH NO!!! I just spent the last 2 days reading over this thread that was dug up from the past, and there's not really any concrete findings! how anti-climactic.

alrighty, I'm going to read it over again, and see if I can jump in here like double dutch. thus far, this is what I take:

buy high wattage powersupply
bypass rectifier for DC voltage in
start poking around until something blows up.

anyone have some good recommendations from all this research?

Sim


----------



## rfengineers (Jun 2, 2008)

I bought two of these devices, blew one up and scavenged the other for parts.

I recommend buying a dc-to-dc converter, or at least a dc powerable battery charger like the Iota DLS-45.

OTOH, it did work for Gavin.


----------



## simey_binker (May 13, 2009)

for looking for a "dc powerable battery charger" - how do I know if I can bypass the rectifier? is it pretty standard to have a high-voltage AC-DC rectifier before dropping to a useable DC voltage? would there be a case where it drops the voltage first, then rectifies. 

apologies, I'm a mechanical engineer, not electrical. this is all Greek to me.

Sim


----------



## rfengineers (Jun 2, 2008)

simey_binker said:


> for looking for a "dc powerable battery charger" - how do I know if I can bypass the rectifier? is it pretty standard to have a high-voltage AC-DC rectifier before dropping to a useable DC voltage? would there be a case where it drops the voltage first, then rectifies.
> 
> apologies, I'm a mechanical engineer, not electrical. this is all Greek to me.
> 
> Sim


I've been using an unmodified Iota DLS-45 and a 38 Amp-hr AGM battery to power all my accessories. Almost 1400 electric miles later the only problem I've had with the set up is a loose connection between the traction battery and the dc-dc converter.


----------



## simey_binker (May 13, 2009)

sounds good. so you hooked the ~144vdc directly into the AC line? there was previous discussion about this, but lazzer was saying it only utilizes ~1/2 of the do-dads* on the rectifier, and you could potentially damage it (which, damaging the rectifier wouldn't matter, considering you're not planning on using it anyways). 

*the term he used escapes me.

what dc voltage are you feeding to the powersupply, and where are you feeding it to?

thanks,
Sim


----------



## Anaerin (Feb 4, 2009)

simey_binker said:


> t lazzer was saying it only utilizes ~1/2 of the do-dads* on the rectifier
> 
> *the term he used escapes me.


Close. Diodes. I can see where you get confused.


----------



## simey_binker (May 13, 2009)

ha ha - I should have known that. pretty straight forward, but its getting late here. I nearly have more respect for myself that I called them "do-dads" which is similar to "diodes" - but had I been thinking of something like "capacitors" I probably still would have used the word "do-dads".

so uh, I should just purchase one, patch in through the AC lines (pre-rectifier), and hope I don't blow the diodes. if I do, then I have no other choice than to bypass it.

Sim


----------



## rfengineers (Jun 2, 2008)

simey_binker said:


> sounds good. so you hooked the ~144vdc directly into the AC line? there was previous discussion about this, but lazzer was saying it only utilizes ~1/2 of the do-dads* on the rectifier, and you could potentially damage it (which, damaging the rectifier wouldn't matter, considering you're not planning on using it anyways).
> 
> *the term he used escapes me.
> 
> ...


I use a 120VDC system, ten 12-Volt FLA batteries in series. I feed the DC directly into the Iota with no internal mods. I probably should bypass the internal rectifier, but have not done so.


----------



## afrokng14 (Jun 27, 2009)

Is there a DC/DC converter that will allow more than 30 or 60 Amps+? I have a 2 car amplifiers rated at a max current draw of 60Amps a piece that I would like to use in my EV build on top of the H.I.D. lights, and other accessories. I could use one but I would love to use both. I won't be constantly drawing 60 Amps but I would like to have a system that if needed could respond. These will be my short trip days when I'm at the car show showing off my EV


----------



## rfengineers (Jun 2, 2008)

afrokng14 said:


> Is there a DC/DC converter that will allow more than 30 or 60 Amps+? I have a 2 car amplifiers rated at a max current draw of 60Amps a piece that I would like to use in my EV build on top of the H.I.D. lights, and other accessories. I could use one but I would love to use both. I won't be constantly drawing 60 Amps but I would like to have a system that if needed could respond. These will be my short trip days when I'm at the car show showing off my EV


I suppose that you could use two separate dc-dc converters, one to drive the first amp and another to drive the second amp.

This will take some thought to determine how much isolation you will need to maintain (if any) between the two systems.

OTOH, Since the amps don't draw max current continuously, you don't really need the dc-dc to deliver 100% of your current. Just use a bigger 12V accessory battery to take up the slack during the peak current times.


----------



## afrokng14 (Jun 27, 2009)

rfengineers said:


> I suppose that you could use two separate dc-dc converters, one to drive the first amp and another to drive the second amp.
> 
> This will take some thought to determine how much isolation you will need to maintain (if any) between the two systems.
> 
> OTOH, Since the amps don't draw max current continuously, you don't really need the dc-dc to deliver 100% of your current. Just use a bigger 12V accessory battery to take up the slack during the peak current times.


Hmmmmmm....I didn't even consider running the system on a seperate battery. If I did that should a use a CAP in conjuction with it? Also how would I hook it up to get the same 12volts the DC converter would supply so as to allow me to turn it off and on and charge as well with the car being off. In other words I font want to run a seperate system and have to worry about forgetting to disconnect the amp battery


----------



## rfengineers (Jun 2, 2008)

afrokng14 said:


> Hmmmmmm....I didn't even consider running the system on a seperate battery. If I did that should a use a CAP in conjuction with it? Also how would I hook it up to get the same 12volts the DC converter would supply so as to allow me to turn it off and on and charge as well with the car being off. In other words I font want to run a seperate system and have to worry about forgetting to disconnect the amp battery


Here is how my dc-dc is hooked up. I put in a switch so I could turn off the converter while charging. That turned out to be unnecessary, I leave the dc-dc converter on while charging the main traction battery and have had no problems


----------



## phoenixosu (Jul 12, 2009)

I would just like to say that this is bloody brilliant, I've been agonizing over getting a $200 supply from digi-key to step 72V to 12V to power the instruments on my motorcycle. mad props on the hack idea.


----------



## favguy (May 2, 2008)

The Iota DLS-45 looks like a very nice solution, the spec. shows max input of 132v AC, does anyone happen to know if it has the tolerance to work with a 144v DC system without going bang?, anyone tried this?

Regards

Paul


----------



## Twilly (Jan 22, 2008)

I would think so... Remember 132 vac is a average voltage, 132 vac will peak much higher


----------



## lazzer408 (May 18, 2008)

favguy said:


> The Iota DLS-45 looks like a very nice solution, the spec. shows max input of 132v AC, does anyone happen to know if it has the tolerance to work with a 144v DC system without going bang?, anyone tried this?
> 
> Regards
> 
> Paul


 
Sorry I've been so busy. I'm finally moved into the new house. I knew I had alot of crap to move but damn.  Glad to see many of you hopped on this to help out.

So... Quick $.02 worth. An SMPS rated at a max of 132vac should handle ~170vdc with no problem. Typically I see 150-160v on the main filter cap in line-powered supplies. Peak to peak for 120vac is 156v, if my memory serves me, which is why you'll see 150-160vdc on the main cap. 132vac put it around 170vdc on that cap.

And guys... GET RID OF THAT RECTIFIER!  You dont even have to remove it. Just solder to the + and - side of it. With a DC source on the plug your forcing all the power through just 2 of the 4 diodes in a bridge. If the OEM used a bridge rectifier "just big enough" guess what? Your now 1/2 of "just big enough". You let out all the magic smoke.


----------



## dataman19 (Oct 7, 2009)

OK - It is November 2009 - Has anyone solved the Switch Mode Power Supply Problem Yet?
This thread seems to be pretty well dead with no posts....
...
I have read the entire thread...
..
I am also a component level computer repair tech - and have even repaired many high end power supplies and managed to put the "magic Smoke" back into them.
..
I am going to look into for my Power schematic archive and see if I can come up with an "actual" schematic.
..
Yes the power supply does use an "over voltage" sense loop, and yes there are only three basic circuitry designs.
..
The switching power supply does rectify the incoming AC to a DC voltage. The DC Voltage does get chopped by the two switching transistors (which are basically flip-flops) and then the switching DC is stepped up to a high voltage - which is sampled and then used as a "trigger sense". The 5V and 12 power outputs are then re-rectified and filtered to provide a pure dc output. The second over-voltage protection sense is taken off the 12V power. These two are compared to a reference (the reference uses a zener with a temp compensated reference load) voltage. Should either of the over voltage sense voltages exceed a trigger (a maximum limit) the power supply is shut down.
..
This is a UL Safety requirement. Peter Chow (The original Engineer who designed and patented the switch mode power supply design) designed these to be rugged and reliable.
...
lazzer408 is giving the correct advice to all - Don't go through the AC Rectifier - BYPASS IT!!!! Sure any 1st year electrical engineer will tell you that you are only using half the rectifier - and that the other diodes are reversed biased and will block the current flow in the wrong polarity. This is true. But consider this.... a diode has a PIV rating of xxVolts. This means that the diode will break down and short if the PIV is exceeded. When it shorts it burns out (releasing the magic smoke) because the momentary short causes it to do so. So, my point is simple - Do You Know What The PIV Rating of the AC Rectifier is? Do you know what the short term and long term tolerance is? Do you know the variance from temp to temp? I DIDN'T THINK SO.... So just bypass it.
...
Meanwhile, have you figured it out? I haven't seen any posts saying so.
..
I will post the reference schematic when I find it.
..
Until then.... Good luck all..
..
And I think this thread has been exceedingly interesting and informative.
..
I just would like to see it's ending..
..
Dave R.


----------



## Dennis (Feb 25, 2008)

I reversed engineered a switching power and posted in an diy AC controller thread on here. It was like way back and if you want to, just simply search for it. I even provided a schematic.. I also do not recommend any commercial grade power supplies for the simple fact that the components are 0C to 70C rated rather than -40 to 85C rated which is the minimum I would recommend for any type of electronics that are exposed to the elements like those in automobiles..While it does not get 85C on Earth, it DOES get much colder than 0C in the winter time in the northern areas of American and of course both the poles are also very cold. Reliability is extremely important in an automobile. I Would not want the DC-DC converter to go out suddenly from being exposed to -30C temps and be stranded in the middle of nowhere in a frozen wasteland..


----------



## PROFGOBELI (Mar 25, 2008)

*Quick charge single lead acid cell*

Hello
Don't mean to hijack but seems appropriate and maybe dead anyway. Read this entire thread and did not find ref to an easy way to charge a single cell with these (or ATX) supplies. I bumped 3.3 v 30A down, 5v 25A up, hooked all yellows together, all reds together, and all blacks. Hooked yellows to one jumper clamp, reds to other and have a nice 25A 2.3V single cell booster for my house bank. Later.


----------



## Tim_Fred_007 (Feb 5, 2011)

*cm6800 mod*

the cm6800 chip can be modified so that the power-supply puts out a higher voltage.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817121069
146 amps for $79 (mfg claims 68 amps?)

here again is the product page for cm6800
http://www.champion-micro.com/datasheet/Analog%20Device/CM6800.pdf

and the two chips it says are pin-for-pin compatible/interchangeable with
http://www.fairchildsemi.com/ds/ML%2FML4800.pdf
http://www.fairchildsemi.com/ds/FA%2FFAN4800I.pdf

I need 14-16 volts instead of 12, for a project of mine.


----------



## Tim_Fred_007 (Feb 5, 2011)

*228 amps 12v ~$200, easy to mod voltage*

228 amps 12v ~$200, easy to mod voltage

six 12v rails at 38 amps each = 228amps

features voltage adjust knob.
11.8-12.6? we will see about that 

http://www.evga.com/PRODUCTS/enlarge.asp?PN=100-PS-1200-GR&I=6
rebranded, i cant seem to find the original atm


----------



## DJBecker (Nov 3, 2010)

*Re: 228 amps 12v ~$200, easy to mod voltage*



Tim_Fred_007 said:


> 228 amps 12v ~$200, easy to mod voltage
> 
> six 12v rails at 38 amps each = 228amps


That's the power limit of the cables, and it's a pretty optimistic estimate.

You can't draw that current from all the rails at once. You may not even be able to draw the rated 68 amps without having a load on the 5V rail. 

An advantage of computer power supply cables is that they can assume moving air to cool the wires. That lets them use a much smaller gauge wire than in other uses e.g. wire in conduit. If your installation does not have the same wire cooling (it almost certain doesn't), you should de-rate the capacity.


----------

