How do generators for flashlights and other electronics work just by shaking?

Answer 1

The same way all generators work: when you put a wire in a changing magnetic field, an electric current is generated in that wire. It's called "electromagnetic induction".

When you shake the flashlight, you're making a magnet in the flashlight move up and down, thus creating a changing magnetic field in a coil of wire that is also in the flashlight. That generates electric current that charges the flashlight (it stores the electricity in a battery, i believe).

You can read about the physics of it in a bit of detail here (under "Faraday's Law"):
http://cref.if.ufrgs.br/hiperfisica/hbase/electric/farlaw.html#c1

Answer 2

Good question. It would be a lengthy answer in full so I will simplify. Of the flashlights that I have seen that you shake, it is a magnet that is moved up and down while shaking. The magnet has a field of flux around it that "cuts" a coil of wire at 90 degrees thus producing electricity with the most efficiency. On the end of that coil you will find a fairly large capacitor for the storage of energy that you create by the shaking of the light. The capacitor acts as the battery. This a very simplied answer. Hope that helps.

Answer 3

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Answer 4

.Shacking produces a moving magnetic field. The moving magnetic field produces a current in a conductor which charges a capacitor which can be used to power a flashlight

Answer 5

First answer is right, but I add that the electricity is generated is usually excess of the light needed, so the excess is stored in a battery (in the newer ones, an ultracapacitor) for later use.

It helps you have a smoother light and be ready on demand, rather than trying to shake the light as you're trying to shine it on something!