We think of electrolysis as a way to split things like water into oxygen and hydrogen using electricity, but it has a second meaning which is to remove hair using electricity. An electrologist inserts very thin needles into each hair follicle and uses a burst of electricity to permanently remove the hair. [Abbxrdy] didn’t want to buy a cheap unit because they don’t work well and didn’t want to spend on a professional setup, so designing and building ensued.
You’ll have to read through the comments to find some build details and the schematic. The device uses commercial electrolysis needles and a DE-9 connector socket as a holder. The device can supply 6 to 22V at up to 2mA. A timer can restrict the pulse to 5 seconds or less.
Any time you are putting electricity in or on someone’s body, there is a danger of shock. For this reason the device is powered with 3 9V batteries and a USB battery for some of the logic. The circuit isn’t very complex, using a few voltage regulators, a 555, and some meters.
If you look into it, electrolysis can work with a DC current like this. In that case, the current forms sodium hydroxide inside the follicle (at the negative terminal) and kills the hair-producing cells. Some devices use radio frequency energy to heat the cells, while other commercial machines apparently use both methods together.