DIY Bench Power Supply

Tired of juggling multiple wall adapters for your electronics projects? In this Instructable, I’ll show you how to turn an old ATX computer power supply into a versatile, multi-voltage bench power source that delivers 3.3V, 5V, ±12V, and adjustable voltages, all in one compact unit. Using just a breakout board, basic tools, and a 3D-printed enclosure, you’ll create a powerhouse capable of running everything from microcontrollers to motors.

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1. XH-M229 PSU Breakout board - https://s.click.aliexpress.com/e/_ooSKHXl
2. Computer Power Supply - https://s.click.aliexpress.com/e/_ooXScYb
3. SK35 Mini DC Buck-Boost Module - https://s.click.aliexpress.com/e/_oDPEAqJ
4. 3D Printer - https://s.click.aliexpress.com/e/_o2CRLHt
5. PETG Filament - https://s.click.aliexpress.com/e/_on9V4ld
6. Assorted Screws Kit - https://s.click.aliexpress.com/e/_olBMrE7
7. Soldering Station - https://s.click.aliexpress.com/e/_onuYyWn
8. Multimeter - https://s.click.aliexpress.com/e/_oEOKuGF
9. Electrician Screwdriver Set - https://s.click.aliexpress.com/e/_oDmBrYf
10. 8 in 1 Mini Screwdriver - https://s.click.aliexpress.com/e/_oDrDD6x
11. Wire Snips - https://s.click.aliexpress.com/e/_o2eJ3IF

You’ll need an ATX computer power supply (any wattage will work), an XH-M229 breakout board, an adjustable DC-DC buck/boost converter, wire cutters, a screwdriver, and a soldering iron. There is a 3D printed model you can get from here to print out.

If you don't own a 3D printer, you can use the 3D printing service from PCBWay to get your parts.

We will be doing a slight modification on the PSU, so make sure that it is unplugged from the mains. Also, these power supplies can hold some charge even after it is powered off, so handle the inside with care and at your own risk!

If you are uncomfortable doing the modification, you can skip it but you will have more wires to handle.

Cut all wires except the 24-pin motherboard connector and one 4-pin 12V cable (for the DC-DC module). Snip them close to the PCB to avoid loose strands. Keep the 24-pin intact—it connects to the breakout board later.

Secure the back of the enclosure to the PSU. Mount the breakout board to the front panel and push one of the connectors in the front opening.

Mount the banana plugs to the SK35 module case and secure some wires to them with the provided mounting clips. Once that is done, secure the case to the top of the PSU front case, wire the 4 wires to the module and push it in to be seated inside the enclosure.

The front and back faces of the enclosure connect with 4 pillars that are screwed together with M3 bolts. Screw each of the pillars to the back of the PSU first, twist in all the cables in the front and secure the case from the front as well.

Plug in the PSU and flip the breakout board’s switch. Use a multimeter to verify outputs: ~3.3V, ~5V, and ~12V. Adjust the DC-DC module to your desired voltage (e.g., 9V) and confirm it holds under load.

This is a relatively easy project that you can make in an afternoon and will be extremely helpful if you are just starting with electronics or if you need an additional power supply as I did.

If you liked this project, you can check out my other Instructables, or you can check out my YouTube channel for more projects and electronics videos.