Constant Current Load

This is a simple active constant current load ideal for testing power supplies. The design will handle up to 70V / 5A, with a selectable full scale that allows precise low current loads as well. I've built many variants of this basic concept over the years, including multiple-transistor units capable of drawing more than 20A continuously.

View schematic, PCB has been shared at OSH Park.

Last update: 17 July 2016
© Steven J. Merrifield