On Fri, 24 Apr 2009 10:06:59 +0100, Baron
put finger to keyboard and
composed:

A lot of the better ones have suitable loading built in ! More often
the PSU wont start up if it requires a minimum load, though some will
but don't regulate the output voltages properly. The regulation is
done with reference to the 5v rail ...

I haven't repaired many AT/ATX PSUs, but IME they usually (?) regulate
by sensing a weighted average of the +5V and +12V rails. This means
that the +5V and +12V rails move in opposite directions.

See
http://groups.google.com/group/alt.c...5?dmode=source

- Franc Zabkar
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