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Inside a USB powered heated neck muff (with schematic)

Aside from the very weird and misleading product images on eBay (it's not full of beads or radioactive), this isn't too bad for what it is. I'm not totally convinced it's better than a plain scarf, but it does heat the back of your neck with a 4.5W panel. The listing claims the unit is washable, and to be fair, the USB connector has a tight cap, the control module is potted in silicone and the heating element is very soft and flexible. The heating panel is made with what appears to be a carbon fibre and polyester thread, literally overlocked into place with plain thread, and is terminated to wires with brass-themed steel crimps. The control module is quite useful. It has very simple construction and a staggering 12 LEDs for even button illumination. It has a classic 8-pin chip, a MOSFET for switching the heater, and very few other components. Heat level is in three stages:- Red = 100% duty cycle Blue = 75% duty cycle Green = 60% duty cycle (maybe 50%) The module could switch other loads too, but inductive ones like motors would require a flyback diode across the coil. The module could even be used as a slow sign flasher. These are all over eBay if you search for heated scarf. There's a huge price range. This one cost £6 including local UK shipping. If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- https://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