Today I tested a 12V 5A 60W switching power supply that cost me only $3 including shipping from China. The listing says it's for LED strips, CCTV and LCD monitors. The actual current capability is only 3.5A and some parts are underrated. The PCB board definitely seems repurposed. It looks bodged, but I have seen much worse SMPS designs :). This one has a proper fuse, EMI filters, very good isolation distance on the PCB and safe X2, Y1 capacitors. I managed to reverse engineer a full schematic of it. I also explain in detail how does this switching power supply work. One of the viewers helped me to identify the control chip as XN1049 (thanks!).
Autopsy of the switching transformer:
https://youtu.be/tWG0SNYzFRI
You can support me on Patreon:
https://www.patreon.com/DiodeGoneWild
