Inside a cheap AliExpress fluorescent ballast (Patreon)

Cheap AliExpress ballast (with schematic)

This fluorescent lighting ballast is a very good demonstration of a design that has gradually got so refined that it's cheap, but also usually very reliable. The mid point tap from the two power supply capacitors may be a way to reduce the voltage to simplify the circuitry. It's odd to see one of these without a capacitor in series with the tube, but that might be because it's a better or cheaper way to implement a higher power ballast. The case metalwork is thinner than normal. It's also notable that while there's plasticised card under the PCB as insulation, there's none between the ends of the capacitors and the metal enclosure. The capacitor cans aren't usually electrically connected, but it's generally a good idea to treat the bare metal end as live. It would have been good to test this with a tube, but I don't have one here. It's kinda pleasing to see that the main differences between a compact fluorescent lamp and a full size fitting are basically just the scale of the circuitry. If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty. #ElectronicsCreators