Editing Flashlight (section)

=== Mechanical power ===
{{Main|Mechanically powered flashlight}}
One type of mechanically powered flashlight has a winding crank and spring connected to a small [[electrical generator]] (dynamo).  Some types use the dynamo to charge a capacitor or battery, while others only light while the dynamo is moving. Others generate electricity using [[electromagnetic induction]]. They use a strong permanent [[magnet]] that can freely slide up and down a tube, passing through a coil of wire as it does. Shaking the flashlight charges a [[capacitor]] or a rechargeable battery that supplies current to a light source.  Such flashlights can be useful during an emergency, when utility power and batteries may not be available. Dynamo-powered flashlights were popular during the Second World War since replacement batteries were difficult to find.