Dynamo
The electricity is produced in the dynamo and sent through the wire to the lamp. Maybe you are wondering why there is only one wire when it always takes two to make a circuit.
Well, the frame of the bicycle replaces the other wire.

Click the dynamo.

Dynamo lamp on bicycle
Wind Turbine Generators
Synchronous Generators
Changing Generator Rotational Speed
Asynchronous (Induction) Generators
Changing the Number of Generator Poles
Variable Slip Generators for Wind Turbines
Indirect Grid Connection of Wind Turbines
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