# What devices have dynamos

## Dynamo as an example: This is how a generator works

To understand how a generator works, it helps to take a closer look at an object that everyone knows: the dynamo. Ultimately, the small device on the bike is nothing more than a miniature generator.

### Energy from the legs runs a small generator on the bike

In short: a generator converts mechanical energy into electrical energy. In the case of larger generators, this kinetic energy is often provided by diesel engines; in the case of dynamos, it comes from the muscle power of the person who rides the bicycle. But apart from the type of drive, the underlying principle is the same as with any generator - namely the induction principle.

### Induction principle: centuries-old technology behind the generator

The first generators were built in 1832, when the English physicist Michael Faraday discovered the induction principle. This principle is based on the discovery that electrical charge in a conductor, such as a wire, is shifted when it moves across a magnetic field.

As a result of the movement, the electrons shift in such a way that there is a shortage of electrons on one side of the conductor and an excess of electrons on the other. As a result, there is an electrical voltage between the ends of the conductor - that is, current flows.

The faster the conductor is moved through the resulting magnetic field, the higher the voltage generated.

### How does a dynamo work?

A permanent magnet, the so-called rotor, rotates in the dynamo. Depending on the design, this can also be outside the dynamo. This rotor is surrounded by a tightly fitting wire coil, the stator.

When the rotor, which is connected to the friction wheel on the head of the dynamo, begins to turn, electrical voltage is generated in the wire coil. This electrical energy is then diverted via cables that are connected to the coil - ideally, the lights on the bike will then be on.