DIY PSU Into Bench Power Supply




Introduction: DIY PSU Into Bench Power Supply

Always loved electronics. I like to reuse parts or componets and I Love to be part of the Instruc...
This is my bench power supply made out of an PSU. Any questions....? I'll be glad to help.

And here is the schematic.. (in the schematic there is a mistake, the USB should be connected to ground an +5 instead of -5)

And here you can see a graphic schematic.



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81 Discussions

how did you manage to connect both the multimeter wth the PSU, realy cool idea. kindly explain.

So... I put together the variable voltage circuit on my breadboard, hooked it up to the pos and neg 12V of my power supply. Turned it on and it was putting out about 22V at first, then as I started to turn the potentiometer, the pot went up in smoke. The pot that I got was rated at 5k with a power rating of 0.5watts. I'm assuming the 0.5w is not high enough. Anyone know the minimum rating that is needed for this? My initial guess would be to calculate the watts coming out of the -12V lead on the power supply and use that as a bare minimum.

Any plans on posting a step by step for this instructable? I do hope you do, I would like to build one just like yours to test with Halloween props.

2 replies

Hi there! I don't have this power supply anymore. Did you check my other power supply instructable?

I have, I still like this one the best for the ideas I have for it. If you do make another I would love a step by step. Working on a low voltage haunt and these would be great.

Hi, I've build a similar unit, but when i try to draw more current it shuts down. The most current i saw om my meter was around 500mA, on the PSU itself it says: 16A at 12V, 13A at 5V and so on. Have you any idea where the problem could be?

1 reply

Hi there, I have was just poking around for some power supplies conversions, and yours looks very nice. A question, though... Is it possible to get 15v out of your set up by combining the -12v and the +3.3v?

Nice work, i have a question about this psu from dell NPS-330CB C well i did some search on net for pinout it turned out that grey wire is for PWR-ON ok short it with which wire to switch it on. yes switching is main problem help needed.

Hey there, very nice writeup.. please tell us when will you update your new instructable for the new Bench Power supply?

1 reply

Hi there! The instructable of my new bench power supply is on line an running, see it here

Is there a specific type of relay you used for this?

Great project!! I have one question though. You show the connections for the USB charger port connected to -5v and GND. Should that be +5v instead?

4 replies

Ups! Thank you for pointing that out, it is a mistake of course. You need to connect the usb to Ground and +5. Sorry about that.

I have one more question. On your schematic what is the switch actually connected to other than ground?

Thanks for this circuit, I've had fun putting it together but have a small problem. I can only get a touch over 12.3v across the regulated output (LM350K). I've double checked the circuit and confirmed that I have 23v across the input (ceramic capacitor). Can't quite work out what I've done wrong?