# Variable power supply need some opinions



## Hellraiser1981 (Jun 14, 2005)

I am currently designing a high-current variable PWM switching power supply for 3 peltier coolers I will be using in the near future.  I would like any opinions or new ideas regarding the design.  Posted are the two modules I have designed so far.  This power supply is a part of the custom exterior ATX PSU (computer case mounts on top of it) I am designing for use in my own system and will hopefully patent soon. (800W ATX with all independent, adjustable rails, dual +12, built in UPS, 12v standby, with a  500w+ variable, temperature controlled output for TEC's)  
The AC input is not designed yet, but will just be a bridge rectifier with a choke and Filter caps which will yield ~+145v from a 110VAC input.
The partial design posted should work, I just haven't built it yet.  Some of the parts aren't specified, but I will keep updating the pictures as I make progress.  
I am releasing these prototype schematics to the public in hope of getting some new ideas for it.
Thanx in advance for any, and I mean ANY ideas.

Added 6-13-05:
Finished designing the AC input (here's another schematic).  Very straight forward design and should be able to handle a lightning strike without blowing anything other than the replaceable surge module (outlined in grey on the AC circuit)  It's overkill for just a 12v supply, but it'll also supply power to the ATX P.S. section of the unit.


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## W1zzard (Jun 14, 2005)

looks good from what i can see. maybe check out using a microcontroller (i like atmel) for the pwm part. it gives you much more flexibility, you have to know some c programming tho.


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## Hellraiser1981 (Jun 14, 2005)

I do like the idea of using a microcontroller, but it isn't necessary for my application.  Although, I could interface it with the computer and control it with software (any programmers out there?)  I'm a hardware guru, so C is out of my league.
I just need to built a multi-comparator circuit for the temp control and protection circuits (both in very rough draft on paper).


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