AC Generator (Alternator)


    An electrical Generator is a machine which converts mechanical energy (or power) into electrical energy (or power).

Principle :

   It is based on the principle of production of dynamically (or motionally) induced e.m.f (Electromotive Force). Whenever a conductor cuts magnetic flux, dynamically induced e.m.f. is produced in it according to Faraday's Laws of Electromagnetic Induction. This e.m.f. causes a current to flow if the conductor circuit is closed.

   Hence, the basic essential parts of an electric generator are :

             A magnetic field and

             A conductor or conductors which can so move as to cut the flux.

Construction :

    A single-turn rectangular copper coil abcd moving about its own axis in a magnetic field provided by either permanent magnets or electromagnets. The two ends of the coil are joined to two split-rings which are insulated from each other and from the central shaft. Two collecting brushes (of carbon or copper) press against the slip rings.

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