Electronic Circuits and Projects Forum

This was a great video, but I do have one big issue with it: His drilling "technique":

1) You should -never- use a power drill while holding the part being drilled by hand. If the drill should catch or slip on the material, things could get nasty (I've learned that lesson the hard way more times than I can count - I guess I am a slow learner!)

2) When modifying a case, you should remove all electronics from the case first, then reassemble after modification (I don't know how none of the chips/swarf from drilling out those holes didn't short out the power supply, but by disassembly, you can make sure the supply is clean of this debris before re-assembly)

I did like that small heat-gun (or SMT resoldering station? Couldn't tell) he was using - I wish I had one for my bench...

Couple of little bit falls. He talked about placing a minimum load dummy resistor on either the 5v or 12v rails. This is because the primary feedback for voltage regulation is accomplished on these rails (5v old, 12v new supplies). Without them the power supply will likely be unstable.

He did not mention the other rails' voltage is solely based on the transformer turns ratio of each winding of the secondary. There is no individual regulation control on these other lines. The primary control voltage regulation is only on the 12v supply for new power supplies. This make the voltage regulation on the other voltage supply outputs rather poor as their loading varies.

The outputs are rather noisey due to the direct switching regulator output. I would not use them directly for any analog circuitry where power supply noise level is important. The audio circuitry on a computer motherboard has power supply filters and on board linear regulators to create a clean supply.

I know this is an old post but I think all of these converting ATX Power supplies are way over-rated. I simply just bought a old dvd/cd/video cd sharp dv-740 player from a junk sale for 3 dollars took out the entire first pc board and hook up some alligator clippers to it anytime I need power supply. It is so well built that noise is minimum and best of all it is already ready to go.

Originally Posted by 3v0

What is your beef with them. I have a nice bench supply but the ATX comes in handy when I need more voltage sources.

No Beef. I have one also. But doing it the other way offer same thing without going through so much trouble. Just take out a couple of screws, plug in and hook up your alligators. Just wanted to let others know there are better alternatives and cheaper. It does make a nice weekend project, hope I did not sound rude.