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Electronic Dummy Load, 0–10 A
In designTest gearPower supplies
Last updated 4 October 2026
Testing a power supply properly means loading it. This constant-current load draws anything from 0 to 10 A, set on a 10-turn pot, from supplies between about 0.6 V and 30 V, up to 100 W.
Four IRF540s, each with its own op-amp and 0.1 Ω sense resistor, share the current exactly. A panel meter reads volts and amps, and a thermostat on the fan-cooled heatsink switches the load off if it overheats. It works low enough to test 1.4 V and 2 V valve filament supplies.
At a glance
| Current | 0–10.9 A constant current |
|---|---|
| Voltage | 0.6–30 V (0.15 V at 2 A) |
| Power | 100 W with a fan-cooled CPU heatsink |
| Status | Design |
Documentation
The full design report, schematics and parts list will be published here once the project has been built, tested and filmed.