I'm working on a VHS adapter that uses a VHS Cassette casing with some electronics in it. The hardware contains a battery and some sort of IC which I can Not program, it's not a micro controller, it's a fixed piece of hardware that does a specific task.
I do not want to use a microcontroller, the hardware that I use is the only hardware that I am allowed to use because of energy efficiency reasons.
To run the hardware I use a 3.7 V LiPo battery and the only thing I need now is an analog/mechanical momentary switch which is linked mechanically/magnetically (preferred) to one of the wheels of the VHS Cassette.
This momentary switch makes sure that the hardware is powered ONLY when the VHS Cassette wheel is spinning.
How do I create such a momentary switch?
I have one solutions to this but then again I'm not sure how to accomplish it.
Solution: Putting a magnet on one of the wheels, and use a reed switch to charge a capacitor that in turn powers the rest of the hardware.
Pros: should be really cheap, is more or less solid state. Awesome!
Remember the following things:
I only allowed to use the hardware mentioned: The IC, the battery and a momentary switch. -There should be as little moving parts as possible, it's preferred to be completely solid state. -No digital sensors allowed. -No microcontroller allowed.