A generator usually means a machine that makes electrical energy. It has a generator head with wires, spinning inside a magnetic field. The resulting electromagnetic induction makes electricity flow through the wires. Hybrid electric vehicles carry a generator powerful enough to make them go. The biggest generators don't go anywhere; they stay in their power station.
Different things can be used to make the generator head spin. Some small ones are cranked by someone's arms or legs. Bigger ones are connected to an engine. The biggest ones use a steam turbine or hydroelectric water power. Some use wind power. Whatever makes it turn, the generator converts this energy into electrical energy.
Simple generators have:
- a rotor, which is the moving part of the generator
- an axle
- a magnet
Some kinds have:
- a commutator, which is a switch that reverses the current
- a power supply to start the generator
The Faraday disk was the first electric generator. The horseshoe-shaped magnet (A) created a magnetic field through the disk (D). When the disk was turned, this induced an electric current radially outward from the center toward the rim. The current flowed out through the sliding spring contact m, through the external circuit, and back into the center of the disk through the axle.
This large belt-driven high-current dynamo produced 310 amperes at 7 volts. Dynamos are no longer used due to the size and complexity of the commutator needed for high power applications.
Ferranti alternating current generator, c. 1900.
Electrical generator Facts for Kids. Kiddle Encyclopedia.