Electrical generator
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 power stations.
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.
Some portable generators have an internal combustion engine. They are harmful when used indoors because they make carbon monoxide.
Components
Simple generators have:
- a rotor, which is the moving part of the generator
- an axle
- a magnet
- brushes
Some kinds have:
- a commutator, which is a switch that reverses the current
- a power supply to start the generator
Electrical Generator Media
U.S. NRC image of a modern steam turbine generator (STG).
Early Ganz Generator in Zwevegem, West Flanders, Belgium
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.
Hippolyte Pixii's dynamo. The commutator is located on the shaft below the spinning magnet.
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.
A small early 1900s 75 kVA direct-driven power station AC alternator, with a separate belt-driven exciter generator.
Hydroelectric power station at Gabčíkovo Dam, Slovakia
Hydroelectric power station at Glen Canyon Dam, Page, Arizona
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