An older, inexpensive 13.8V DC power supply with 22A (continuous) output drive capability. Repaired and modified a couple of years ago. A look inside, load testing, schematic review and simulation results.
Some added comments which I didn't cover in the video. Based on the power derating curves for the 2N3055, the case temperature for the transistor should have been kept under 65 degC for the tests I ran, while mine were operating at around 80C. Too hot for sustained operation driving 350W like I did here. I will need to replace the fan switch to turn on around 60C. For currents under 12A, the current fan set up is OK. Future: dynamic testing with a switched load.
