DC Power Supply Alternative

A standard computer power supply can be found for less than $30 these days and can provide 24vdc @250 watts or more, it can also provide 5, 7, 10 and 17vdc. It can also be converted to be a variable supply.

The wires:
Black = common (0v)
Red = +5v
White = -5v
Brown = sense wire (connect to orange
Orange = 3.3v (do not use, just connect it to the brown wire)
Yellow = +12v
Blue = -12v
Gray = LED (go thru a 330 ohm resistor)
Green = power ON (can be attached to a black wire or put thru a switch).

The older ATX are slightly different, I will eventually show the details on a page.
I have this posted on the patchn.com forum in Tips and Trick and plan to add more information about this on the site. Many people and businesses have old computers laying around so if a need arrives for DC power supply they can be used. They also make a good test bench supply and can be converted into a variable output.

I've got about 5 old power supplies sitting around, some AT some ATX. How exactly do you get 24V out of them? Thanks for the good information.

+12v to -12(not common)

On older units you had 2 connectors, P8 and P9, that went to the motherboard.

1 Orange "Power Good" P8
2 Red (XT No Wire) +5VDC P8
3 Yellow +12V DC P8
4 Blue -12V DC P8
5 Black Ground P8
6 Black Ground P8
7 Black Ground P9
8 Black Ground P9
9 Black Ground P9
10 Yellow -5V DC P9
11 Red +5V DC P9
12 Red +5V DC P9

The power connectors;
1 Yellow +12v
2 Black Ground
3 Black Ground
4 Red +5v