As part of a series of low-power and power harvesting devices (such as https://steemit.com/technology/@proteus-h/my-diy-passive-mini-radio-microwave-detector), I would like to make a hand-crankable or shakeable torch. I like these projects because they are not too complex, and they demonstrate very tangibly the energy that can be harvested in the environment.
A Servo makes a nice gear reduction (from https://www.youtube.com/watch?v=9dIkxQ_1H1k):
…and a mini version inside a tic-tac container:
And a relay coil with a magnet makes a super tiny generator (from https://hackaday.com/2014/01/13/a-simple-led-flashlight-composed-of-a-relay-and-a-magnet/):
I’m curious to try this circuit with the solar engine voltage trigger circuit…Or to make it into another business card version.