Skeleton shaver teardown
Added 2023-03-09 23:22:56 +0000 UTCTo be fair, this made short work of completely shaving my head. A task complicated by my very dense and fine hair that feels closer to fur than hair.
But that circuitry is squirmily minimalist. I'm not sure if the chip has a dedicated charge control section built in, or if it's using software and unusual techniques to control the charging of the lithium cell.
But it works, and it works well while also managing to look very stylish and being much easier to clean than a traditional shaver.
https://www.youtube.com/watch?v=ePcJ7GsTYHA
Comments
MOSFETs tend to have some capacitance on their gate, so it may be to limit the peak current pulse when that charges. But many generic designs just drive the gate directly with the microcontroller pin. One other useful advantage of the resistor is protecting the microcontroller against MOSFET failure causing high pin current.
Big Clive
2023-03-14 14:58:48 +0000 UTCLove the design of the shaver. What is the purpose of the 100R resistor at the gate of the MosFet. As I understand it MosFets are voltage driven, so no, or very little, current should flow into the gate. The purpose of the 10k resistor to ground is clear.
Zeedijk Mike
2023-03-14 11:11:50 +0000 UTCI have the same one and I've shaved my head with it probably a half dozen times so far and have had no issues.
Jon Ellwood
2023-03-11 18:07:45 +0000 UTC
