need help with 24v DC PWM controler!

[winter]

Hey everyone, names Jay and i've got a small problem...

i'm working on my own alternative fuels project using a water fuel cell. i have everything just about ready to go, the only thing thats getting in my way is a pulse width modulator.

i'm looking to do a 24v DC pulse width modulator to work with a 12v DC input. i'm looking to use an adjustable frequency from 5hz-47khz and a output current of upto 30amp, this would be an input power of 12v DC upto 60amp and a available 95% or higher capable contineous load cycle.

i know this seems a bit complex... but i really need the help and any you all could give would be GREATLY appreciated 

the application is for pulsed water electrolysis in a heavy duty designed water fuel cell. help me better understand and or design a useable PWM for this application and you all would be to thank for helping with a high output water cell that can fully power an engine without the assistance of gas. i've gotten as far as 60% oxi-hydrogen and 40% gas supplied, a PWM will carry me to the finish so if you all can help out, it would be amazing! 

[Rob]

So for me the first thing that comes to mind when you mention those currents is welder.

I don't own and haven't used a welder, but I'd think looking around for circuits in that are would be a useful starting point.

And Welcome to the boards.

[cadstarsucks]

So for me the first thing that comes to mind when you mention those currents is welder.

I don't own and haven't used a welder, but I'd think looking around for circuits in that are would be a useful starting point.

And Welcome to the boards.

12V @ 60A does not sound like a lot of power to me.  We drive 3HP motors at 25A@110V ( the motors are actually rated for 38A )

Dan

[minster9]

how about an ESC made for electric RC planes or helis? I'm runnin' a 25amp esc for my little HBK2 heli,which may pull 200 watts if doin' serious 3d flying. The larger helis use much larger esc's. Important note: if thinking about esc for brushless motor,timing is critical. I don't know how many poles are in the big brushless motors I'm just getting into electric rc,but the high amp components are out there. I'm guessing the number of poles in those big motors(trex 600 class) determines the frequency of current delivery. Maybe Jay needs something like a stepper motor power supply that's got user adjustment knobs?

[cadstarsucks]

there are plenty of FET to do that, but you need more than a PWM to run a brushless