29 Sep
2005
29 Sep
'05
12:24 p.m.
There are Middle-era PC Clone machines that are pretty
much only useful
as power supplies. A few times when I've needed quick-and-dirty 12
volts I have taken an old clone supply and tapped into the yellow and
black of a drive cable connector. The only thing is, the PC switchers
won't start up and regulate properly without a nominal load on the 5
volt line. So you plug in and duct tape an old 3-1/2" hard drive to
the power supply and use it as a 'dummy load.'
In other words it's a kludge. Most, if not all, PC power supplies take
the reguation feedback loop from the 5V output (after all, that's the
important one in the intended application), the 12V line tracks along.
And I doubt there's a crowbar on the 12V line.
And then something fails, you don't have schematics, the parts are
unobtainable, so you grab another old PC power supply and kludge that one
to work...
Personally, I value my toys enough to give them a properly designed power
supply. One that I know is regulated from the output I am using, with a
crowbar, and with proper docuemntation.
-tony