A Dummy Load for Power Supplies

If you acquire an unknown power supply, it would be a good idea to test that supply before connecting it to your radio. Testing may save your expensive radio from being damaged by a bad power supply. To test the power supply, a resistive load takes the place of the radio. This article shows you how to build one to test 13.8-volt DC supplies with varying current levels and a minimum of parts. It will also take you, step-by-step, through the design process.

Designing a Test Load

Three things are needed to design a proper load, and they won’t cost you a dime:

1. Ohm’s Law, I = E / R. I is current measured in amps, A. E is electrical force