DaveM wrote:
"Tio Pedro" wrote in message
...
Is there a feedback sensing line for voltage regulation
in the computer supplies that is accessible?
One trick I've seen done is to diode OR
the supplies, with the sense lines on the common
supply bus, after the diodes. MACom did this
on the massive switchers we used in our old fiber
nodes at work.


There are no sense lines available externally on a PC power supply.

Actually,Alot of ATX supplies have atleast a sense line on one of the
3.3V connections to the motherboard,IIRC it's usually brown,or
orange,and of a smaller gauge than the main wire.
I've seen some older Compaq server supplies that had sense lines on each
rail.

You might
take a look at the article on modding PC power supplies at
http://www.pavouk.org/hw/en_atxps.html. It shows a typical schematic (albeit a
bit aged now). Look at it and you can see where you might bring the sense lines
out of a "master" unit and run them into the "slave" units. No guarantee that
it will work, but I'd rather try that approach before the diode or resistor
solutions.
Of course, your PSUs will be different from the schematic in the web page, but
it should be similar enough that you can figure it out.