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S . ganci
A Wimshurst influence machine : an electrostatic generator developed between 1880 and 1883 by British inventor James Wimshurst .
Thomas Phillips
Michael Faraday , by Thomas Phillips ( oil on canvas , 1841 – 1842 , 908mm × 711mm ).
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Hauksbee electrostatic generator , ca 1705 .
The Van de Graaff generator uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column , producing very high voltage direct current ( DC ) electricity at low current levels . It was developed at MIT in the early part of the 20th century , with the first model being demonstrated in October 1929 , and in 1931 , a version that could produce 1 000 000 volts was described in a patent disclosure .
Michael Faraday and beyond
The foundation for building electric motors was laid with the invention of the battery by Allessandro Volta in 1800 , the generation of a magnetic field from an electric current by Hans Christian Oersted in 1820 , and the invention of the electromagnet by William Sturgeon in 1825 . Nearly 200 years after Guericke created the first electrostatic generator , British scientist
Michael Faraday built the first electric generator , comprising a tube of neutral material wound with a cotton-insulated coil of wire and a bar magnet . Connecting his apparatus to an instrument that detects electrical current , Faraday discovered that on passing the magnet back and forth through the stationary coil of wire , the instrument registered a current flowing .
Faraday was responsible for building the first electromagnetic generator , the Faraday disc ( homopolar generator ): a copper disc rotating between the poles of a horseshoe magnet and which produced a small DC voltage . This same method is used today , with the movement of a copper disc , or wire loop , between the poles of a magnet generating electricity . Long after the original Faraday disc had been abandoned as a practical generator , a modified version combining the magnet and disc in a single rotating part , or rotor , was developed .
Faraday ’ s law
Faraday ’ s contribution goes beyond the invention of the electric generator . Faraday ’ s law of induction is a basic law of electromagnetism predicting how a magnetic field will interact with an electric circuit to produce an electromotive force . It summarises the ways in which a voltage ( or electromotive force [ emf ]) can be generated by a changing magnetic environment ; formulating that emf produced around a closed path is proportional to the rate of change of the magnetic flux through any surface bounded by that path . He would later use these principles to construct the electric dynamo . Even today , almost all electric power , regardless of primary source , is produced using Faraday ’ s principles with the fuel driving a generator ( or turbine ) that then generates the electrical current .
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