A cheap usefull power supply for bench testing boards

[FirePower]

I spend a fair bit of time working on the electronic boards of my SS pin.  After a quick look and a few preliminary tests in the headbox I prefer to remove the board and test it on the bench.  Better access allows good visual examination and I find my hands are steadier to use the logic probe and multimeter. You obviously need the board out to replace components.  A bench power supply can be connected directly to the voltage test points or any place where the correct voltage would appear on the board under test.

A handy and cheap power supply can be made from an old atx style pc power supply - these are everywhere and can usually scavenged from a discarded pc.  They have good regulation and outputs of +12, +5, +3,3, -5 and -12 volts dc. For logic board testing there is ample current available. This makes them fairly useful.
 
It's not a new idea but some may not have seen it, so here is a link describing  how it's done.
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

cheers,
David.

[Marty Machine]

That was certainly one of the better links of modding PC supply for bench use.
I like the fact that he shows you can get Voltages other than 5/12/3.3 etc by using the differences between pos & neg voltages...nice one.

I've used many PC supplies over the years for a quick resource for +5v/+12v at several amps with no probs.

I NEVER found a need to provide a load-resistor, as my electronics being powered was enough load.
I can see the advantage that running a few I.C's on a protoboard might require the power-resistor to load the switchmode into operation.

With the ever falling price of PC supplies, 2nd hand or NEW this is a handy project for the pinny-hobbyist.

Cool stuff !
MM.

[ajlaird]

Got a few of these lying around, so maybe I won't throw them all out.