Alternator

An alternator, also called a synchronous generator, is an electrical generator that converts mechanical energy into alternating current electricity through electromagnetic induction: a rotating magnetic field, produced by a spinning rotor, induces an alternating voltage in stationary stator windings. The technology descends from the alternating current systems developed in the 1880s; the Ames Hydroelectric Generating Plant in Colorado, commissioned in 1891 with a Westinghouse alternator producing three thousand volt, 133 hertz single phase power, is credited as the first industrial use of alternating current. Automotive adoption accelerated in the 1960s once affordable silicon diode rectifiers made compact alternators a practical replacement for the direct current generators cars had used before. Large three phase alternators running at 50 or 60 hertz in power plants generate most of the world electricity, making the alternator the single most common machine underlying the modern electric grid.