A boy winds the crank on his mechanically powered torch radio.
A mechanically powered torch is a torch that is powered by mechanical movement, such as winding a spring and using the stored energy to power it for a small amount of time. It has the advantage of not needing batteries to operate.
Images for kids
A linear induction flashlight is charged by shaking it along its long axis, causing a magnet (visible at right) to slide through a coil of wire (center) to generate electricity.
German dynamo flashlight from World War I. Pulling the pull-chain spun a flywheel, generating electricity to light the bulb on the front for about 5 seconds.