# Congtats to M. Paul Holmes for successful DIY PWM controller



## EV59RAG (Oct 6, 2008)

I am a longtime lurker, but because of Paul Holmes, I have to register here and to ecomoder to thank him for his wonderful work. At first, I thought that it would one of those threads that just talk and talk and talk. But this one is a real gem, to a point that he did it as "open source". A big contribution to the community...

Congrats and thank you.

C


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## ftaffy (Mar 13, 2009)

Only briefly looked at the posts but nice work!


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## MPaulHolmes (Feb 23, 2008)

Ya, great work! hehehe.


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## ngrimm (Oct 19, 2007)

I've been following your project for some time and was glad to see such good results. So far I have only run 72 volts and 400 amps on my 3524 based diy controller but I did have to make a few changes dealing with emf noise when I upgraded from 48 volts. My question is: have you tried voltages higher than 72v yet and if not, do you anticipate any changes needed when you do so? Congrats to Paul and everyone that has been assisting! Norm


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## MPaulHolmes (Feb 23, 2008)

It should be fine up to 144v. Ben used his for a while at 144v without any problems. The mosfets shorted, but it was due to a chattering contactor that couldn't decide if it wanted to be off or on while the control section was turned off. Thus there was no current limiting. I'm fairly certain that it will be fine at 144v now. We'll know in a few days, since I sent one to a beta tester in Phoenix.


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## Bowser330 (Jun 15, 2008)

M. Paul Holmes you have indeed done an amazing job and I salute you and your family.


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## MPaulHolmes (Feb 23, 2008)

The Phoenix controller is doing very well! It's performing better than the Curtis 1231C that it replaced according to the driver! ya! Very smooth takeoff. Throttle controls current, so you don't have to do the stupid 1500 Hz whine.


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## Dalardan (Jul 4, 2008)

Great job, really interesting. Fun to see a DIY controller working in the mess of attempts to do so. Congratulations.

Just for the fun, what are your plans with this controller? To start a small production line and begin selling them? To build up a DIY kit? Just to drive it?

Do you know what are the thermal limits of your design? I do suggest you to try to build a graph showing "time before 55ºC" VS "amp load", it shouldn't be that difficult to do with the right setup, and the 55ºC limit is only a guess of your maximul thermal limit design. This may help you predict if your controller will be able to, for example, power a full sized pick-up truck in a hilly area... 

Again, great job.

Dalardan


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## ga2500ev (Apr 20, 2008)

Paul,

I have your thread in my main browser window and read new posts most every day. I'll ask my question here so as not to clutter the ongoing thread over there.

You've taken two or three cracks at laying out the power electronics (MOSFETS, diodes, caps) for the power section. Given your experience, what do you think would be the most efficient way to build a power section with limited tools.

I'm a longtime embedded systems engineer. So none of the software is really a problem. Plus you've written it all in C anyway so it should be easy to duplicate on the ATMega or port elsewhere.

However, the power section seems to be the bear in getting starting.

Just looking for some ideas moving forward.

ga2500ev


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