Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: NEGATIVE VOLTAGE?
Message-ID: <1991Mar8.182508.15573@zoo.toronto.edu>
Date: Fri, 8 Mar 1991 18:25:08 GMT
References: <1991Mar8.140031.20095@uncecs.edu>
Organization: U of Toronto Zoology

In article <1991Mar8.140031.20095@uncecs.edu> crisp@uncecs.edu (Russ Crisp) writes:
>I can handle the +5, and the +12, but the -12 is vexing me.  Can
>I use another independent 12 volt supply, and reverse the leads...

If the independent 12V supply has no ground in common with the rest
of the system, this should be workable.  However, unless you're working
with something trivial like plug-in bricks, you need to be very careful
about this.

I'm not sure why -12 is such a problem.  The circuits for negative supplies
are no more complex than those for positive supplies, and IC regulators are
just as available.
-- 
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  henry@zoo.toronto.edu  utzoo!henry