How do those weather radio things that you can charge by spinning a handle work?

Question

I have one and it simply intrigues me that it can run without batteries or anything. If it isn't working all I have to do is spin the knob thing around about 30 seconds and it'll start working. I was wondering if anybody knew how this awesome technology worked. I think this is so cool.

Answer 1

Its not that amazing. The handle turns a gear train that steps up the revolutions so it can spin a small generator round really fast. Diodes rectify this into DC and this charges up a lithium button cell.

Answer 2

The reason it works is that modern electronics operate off of very low power and the cell can absorb power very quickly.