Every maker should have a bench power supply in their possession, ready to provide whatever voltage a project or particular component requires. But not all bench power supplies are created equal. Some only have a single output, some have a limited voltage range, and some can’t handle much current. In an attempt to eliminate such concerns forever, Doug Domke built “the Beast.”

This is a beefy bench power supply that can easily handle any project an electronics tinkerer is likely to tackle. It has three outputs that can all operate at the same time. Two of them can be set anywhere from 2V to 30V and can supply up to 10A each, at 30V. However, the supply transformer is only rated for 240 watts. If both are pulling the full current, then setting them above 24V would exceed the rating. But that isn’t a situation many people will find themselves in. The third output comes from a 20W supply that can provide 3V to 30V (positive or negative).

The user sets each output’s voltage with a simple potentiometer, but an Arduino Nano monitors the voltage and current of each using the analog input pins. The maximum 30V is far too high for the Arduino to work with directly, so it takes measurements through voltage dividers. With voltage and current readings, the Arduino can then calculate wattage. It displays the information for each output on a dedicated 16×2 character LCD screen, connected via I2C. 

If you’re in need of a robust bench power supply, the Beast may just fit the bill.