A bicycle dynamo is a small electrical generator attached to a bicycle that produces electricity when the wheels turn. It works on the principle of electromagnetic induction, where movement of a magnet relative to a coil of wire generates electric current. Here’s how it works and what it’s used for:

Working Principle

• When the bicycle wheel rotates, it turns the dynamo’s small roller.

• Inside the dynamo, a magnet spins near a coil of wire.

• This movement generates alternating current (AC) electricity.

Uses

• Powers bicycle lights (headlamp and tail lamp) directly.

• Can charge small devices with additional circuitry (in modern designs).

Advantages

• No batteries needed.

• Provides light as long as the wheel is turning.

Disadvantages

• Produces light only when moving.

• Creates a slight resistance, making pedaling a little harder.