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Dynamo/Generator |
| The electric current used for lighting, heating, and for driving
machinery or trains or trolley buses is made by dynamo electric machines
usually called dynamos or generators. They are made up of magnets and
coils of wire, and driven by steam or water turbines or internal
combustion engines. They electric power they give out comes from the
mechanical power of the engine used to drive them, and
"dynamo" comes from a Greek word meaning power. The first
dynamo was made in 1831 by the Englishman Michael Faraday.
If a wire or coil of wire is moved about near a magnet, a measuring instrument joined to the ends of the wire or coil will show that an electric current has been made or induced to flow through it. (Find out more about induced current here). The stronger the magnet and the more turns in the coil and the faster it is moved, the greater will be the electro-motive force, usually known as E.M.F. (Faraday's Law) tending to make the current flow. As soon as the wire or coil stops moving the electric current will stop too. There are 2 types of generator, D.C. generator and A.C. generator. Click here to see animation. |