I'm using a digispark to cycle the auger of my pellet stove (it's a really old stove there was no electronics to control its power).
All it does is turn the auger on for 3 minutes then stops some time to get the desired duty cycle, it can be set to: off, 1/3, 1/2, 2/3, 5/6 or fully on.
The power supply/relay isn't shown on the picture, it's a board I got from a coffee maker, it supplies 5V and has an onboard relay driven by a transistor, the relay is closed by driving the line low.
