There are exceptions, but generally, a computer supply makes a lousy bench supply. If a LM317 will do what you want, it's easier to start with a small transformer and skip the computer supply altogether. You might get better advice if you stated the voltage/current ranges you need along with other specs like what kind of current limit you need, temperature stability, line/load regulation, noise you can tolerate, etc.
Computer supplies make great...computer supplies. mike
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I don't know the specifics, but as I understand it a computer supply is designed to work at some minimum load, otherwise they tend to be fairly lousy supplies. So unless you want to drop 50W or whatever across a resistor, it's not a good idea.
Chris
Marlin P Jones, and All Electronics IIRC have very nice 120V in 12V out switchers that are actually designed to put out substantial power it
12V. They're surplus so they're not too expensive.-- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Generally the minimum load has to be applied across the +5V output. The reason for this is that the feedback is taken from 5 Volts. Supposedly,
*some* supplies will work with a load of as little as 1 Amp.Tam
I have a two good quality AT computer power supplies (Ipec) and would like to convert them to variable power supplies for bench use.
Is this a simple as wiring an LM317 type circuit to one of the 12V outputs?
Secondly, is it possible to add the outputs for more voltage?
For example, the 5 and 12V outputs in one unit or the 12V of two units in some kind of series arrangement.
Thank you for any suggestions.
Robert
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