On Sun, 14 Sep 2008 17:07:02 -0400, "Charles"
put finger to keyboard and composed:

"Sleepy-Tom" wrote in message
. au...
I tested the power supplies at work and found some had the -5v line not
working.
Ive put these into systems and cant notice any difference between the
ones with the -5v and the ones without.
What is the -5v used for?

RS232 communications, for one.

That requires +/-12V. Some RS232 chips can generate both rails from
the +5V supply via their internal charge pumps.

- Franc Zabkar
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