12V 10A switching power supply (with schematic and explanation)
The schematic in my DB of reverse engineered schematics:
Today I made a teardown of an industrial switching power supply module S-120W-12 in a metal housing. The input is 100-240V AC mains and the output is 12V DC 10A 120W. It came from Ebay and it cost me only $8. In the listing it's called "switching power supply LED driver adapter", but it may have a lot of uses other than just powering LED strips. The SMPS is based on the old good UC3842 control chip, TL431 voltage reference and an 817 optocoupler. It has an open loop protection added, made of discrete transistors. It also has a softstart, a proper fuse, NTC thermistor, safety capacitors, snubber networks, EMI filters, good isolation distance and a relatively safe-looking transformer. The only problem of this switching power supply is the way the power transistor and diode are mounted on the heatsink! Just the sharp corner of it actually touches the aluminium plate! This video got quite long,...