WAYNE CHIRNSIDE wrote in a message to ROY J. TELLASON:

-=> ROY J. TELLASON wrote to WAYNE CHIRNSIDE <=-

 RJT> WAYNE CHIRNSIDE wrote in a message to ROY J. TELLASON:

 WC> What's so hard about rewinding a transformer and replacing the DC -
 WC> DC switching transistors?

 RJT> Must be more to it than that...

 WC>  Why?
 WC>  A ATX supply just rectifies AC - DC then uses the torroid
 WC>  behind a high frequency switcher to downvert the needed
 WC>  voltages.

Yeah,  but there's a considerable difference between switching ~330VDC at
not all that much current and switching many amps at ~12VDC or so.

 WC>  You might need to adjust the torroid core parameters

I wouldn't even begin to know where to start with that one.

 WC> and change the drive oscillators capacitor if as I suspect the 
 WC> driver is setup push pull at a frequency determined by the 
 WC> inductance and capacitance.

I think that the oscillator is likely to be in the chip that runs things in there.

 WC>  Still not much more difficult than I say above.

 RJT> What wattage were the units you saw?

 WC> I believe around 85 watts which is way to light.

Yep.

 WC> Seems manufacturers can make such supplies for those huge wattage 
 WC> car stereo amplifiers and they are pretty darn cheap.

Sure,  but those are only designed to put out _one_ voltage,  and there's
no telling what the other specs are,  in terms of how tight the regulation
needs to be,  etc. -- probably not very.  While there's *some* comparison I
don't think they're exactly what you could call parallel.

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