Every electronics bench needs a reliable power supply, but commercial units can quickly get expensive.

At the same time, ATX supplies from old computers are often thrown out.

These units are perfect for making DIY power supplies because they have a proven track record and can supply adequate current for most projects.

My goal was to take one of these and turn it into a fully adjustable bench power supply that can rival more expensive commercial products.

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The project is built around the ATX PSU and the buck-boost module.

The PS_ON wire (green) of the ATX is connected to GND via a simple slide switch on the front panel that wakes up the supply. A 10W power resistor is used as a dummy load on the 5V rail to keep power stable when powering small loads.

The buck-boost module is only $15 and can output a voltage of 0.6V to 36V with a 5A max current rating. The module also allows you to set a custom current limit.

At the default 5A setting, the module will automatically shut off if the current draw exceeds this limit, protecting itself from damage.

I also added fuse holders to each of the three output terminals for additional safety.

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The front panel of the enclosure is 3D printed out of PLA.

The rest of it is made out of plastic and foam sheets that are hot glued together and aligned with 3D printed brackets.

Fully 3D printed designs could make the project look more professional, but I just needed something fast and cheap.

The panel has standard 4mm banana jacks for the variable output, alongside fixed 5V and 12V outputs