Bench top power supply

in ATX BB, power supply by DP | 6 comments


‏@mattbrailsford tweeted his DIY bench power supply.

You can get one for $14 at Seeed Studio.

This entry was posted in ATX BB, power supply and tagged , .


  1. Todd says:

    I ordered and received this unit. It works fine with my 20 pin PSU, but other PSUs that have a 24 pin main power can not hook up to this board. Do you sell an adaptor to change 24 to 20 so I can attach it to this board? Do you sell a board with a 24 pin connector?

    • Steve Lewis says:

      I was able to cut the connector and separate the extra 4 pins from the connector and it fits fine. The load resistor was not needed for my power supply but it may be needed in future projects. I soldered wires into the holes so I can easily connect them to the load resistor as needed using clip leads or a breadboard.

  2. Todd says:

    I found an adaptor to change 24 to 20 and it works great.$5.99 (microcenter). I thought about doing what you did but I am not a electrical engineer! I do only basic stuff. That is why I am setting up this type of stuff so I can learn more about electricity, circuits, etc.. Thanks for the information.

    Using this board is way better then taking the time to convert an old PSU to this setup. I have like 5 old PSUs laying around and this is excellent when a PSU fails.

  3. someone says:

    On the 24 pin connector, the extra pins are carrying the same voltages you can find on a 20 pin- they are just allowing more pins/conductors to carry more current. Better power supplies may have separate “rails” (regulators that is) for seperate 12 volt dc, but on cheap supplies they are all connected. On many PC motherboards the added 4 pins power the PCIe bus. There is no reason to need the other 4 pins, unless you need the current. As 20 pin power supplies are tossed in the recycling all of the time (obsolete for all but small form factor systems and not hardly worth $14) , why not just cut the connector off and connect the conductors directly to a board with binding posts? Very cheap!

  4. someone says:

    Cut off the connector and tie the conductors to binding posts on a board. Very cheap- a 20 pin power supply is probably not worth $14

  5. Steve L. says:

    If you are so inclined this is an elegant way to build the device into something save and usable. I would take it a step further and add fuses to each power rail to give the inventor a little more control over repairs due to short circuits in their future projects. (

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