Goal
- Learn a way to use end of life batteries
Level
- You should already have done something on breadboard, it would make your life easier. But it's still nice as an introduction to it.
Component
- A ferrite core
- Some cable to do the solenoide
- a resistor (We don't really care about the ohm, between 100 and 400 should do the trick :))
- a simple led triggered by 1.4 volts
- a PNP transistor (in this case the 2N3904)
How to
The circuit is as followed :
More picture will follow