A hand-crank radio is quite similar to a hand-powered generator in terms of operation. It produces power to work via a magnet and conductive wire. An electric current is created as a result of wrapping the wire around the magnet. Once the hand crank located at the side of the radio is twisted, it moves the wire around the magnet, subsequently generating an electric current. A regulator inside the radio helps ensure you don’t damage the circuit even if you roll the crank too fast, and produce too much power as a result.