PC Power supply

[robchava]

Hi every one.

I have a few questions regarding old PCs, since I was "given" a few recently:

1- What are good stuff to take out of old PCs? I can see EPROMS, some big (40 pin) ICs on some of them, but am I missing anything?

2-What are the voltages and currents on the connector of the power supply that goes to the mother board? Does someone have a schematic of how to make this a normal benchtop power supply?

Thanks!

 

[mattg2k4]

1. There are usually lots of small electrolytic caps you can take off, various port connectors might be handy, and I've never checked to be sure, but there's usually several things that look like voltage regulators, usually next to the processor. Floppy drives and hard drives have motors in them, and the power supply will have a bridge rectifier and some nice big caps. Just take a look around. And be careful inside the power supply, that can give you a nice big shock.

2. This has all the pinouts you'll need. Long story short, connect pin 14 (typically green) to pin 15, or any other ground to turn it on. Typically for a switching power supply like this to operate within correct voltage ranges, you'll need a load on it, usually the 5v line. A half amp should do it. Sometimes you don't really need to do that though. But if you're looking into making it a bench supply, I'd recomend it. The current rating of each rail should be printed on the power supply.

 

[robchava]

OK, thanks. That picture is usefull, good thing I´ve been taking some German. I have a few questions still...


1 - Are these parts easily de-solderable? Or if not are they still of any use if I pull them off with short pins?

2 - Also, I have pulled out a few LED displays (where the clock speed used to be displayed), and was wondering if with a A/D converter and these I could make some kind of digital volt and/or amp meter? Any schematics?

 

[robchava]

..... that is 7-segment display...