Re: Digest Number 1042

> Hey Roman,
> Since you have a background on switching supplies, I have a

bunch that I got from some SUN servers but I can't make em' turn

> on. If I give you the info on them do you think you could help? I

haven't been able to find anything.

> They are like 12V 20amp 5V 200 amp. Will I be able to use them

like as a "bench" supply?


Ha ha! You guys are great! What the heck are
you going to do with 5v at 200 amps!!??!

Seriously, the 12v at 20amp is more useful,
but on computer switchers the 5v output is
the main regulated one. You need to run the
5v output at about 5% of its rated current,
maybe 10%. Then the supply should work just
fine.

This means you need a resistor or load that
will always draw 5v @ 10A (and maybe 20A).
This will dissipate 50W (or 100W) so your
room will get hot. Oldtimers like me use a
lightbulb, a 12v 100w highbeam unit from
a car will be cheap and reliable (even at
5v it's dim but works, you may need 2 or to
run both the high and low beams together),
and it won't get as hot as a resistor as some
energy is converted to light, not just heat.
If you DO use a resistor, as always rate
the thing at 4x (watts) more than you need,
so you need a 200w to 400w resistor or
it will cook. I say use the light bulb! :o)
-Roman