Lab Power Supply using an ATX Power Supply

Back when I started tinkering with electronics, all my projects and tests were battery-powered, and for some time time I thought that this was enough for me. But as time went on and I started learning about Operational Amplifiers, I quickly realized that you need positive and negative voltage to power them, this was the moment I realized I needed a Lab-grade PSU. But those were too expensive for a 14-year-old, so I quickly hooped into YouTube and saw a great video on how to create your own Lab PSU.

Although the video was great, I wanted to build a PSU without having to work on 220V lines. So I decided to use an ATX power supply from an old computer to build a similar PSU with the addition of more constant output voltages.

Features

  • Constant high-power +3.3V, +5V and +12V outputs.
  • Constant -12V output, great for powering Operational Amplifiers.
  • One variable output, from 0.6 to 30V, also featuring Contant Current.

Maybe for an bachelors in electronic engineering this may not seem as much. But I end up experimenting with this PSU for over three years, only after I bought a proper lab PSU.

Materials

  • ATX Power Supply. It can be old or new, but should have a maximum power of 500W.
  • Buck-Boost DC-DC Converter with constant current mode.
  • Voltage/Current Display.
  • Green LED.
  • Red LED.
  • 6 Banana Mounting Post.
  • 3 DPDT Switches.
  • 2 Potentiometers, same value as the ones on the DC-DC Converter.

Construction

  1. Drill Holes in the front panel of the ATX Power Supply and mount the corresponding pieces as shown in the photo.

Front Panel

  1. Cut all the wires from the 24-Pin ATX Connector and from any other connectors.