Hippolyte Pixii (1808–1835) was an instrument maker from Paris, France. In 1832 he built an early form of

alternating current Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in w ...

electrical generator, based on the principle of

electromagnetic induction Electromagnetic or magnetic induction is the production of an electromotive force, electromotive force (emf) across an electrical conductor in a changing magnetic field. Michael Faraday is generally credited with the discovery of induction in 1 ...

discovered by

Michael Faraday Michael Faraday (; 22 September 1791 – 25 August 1867) was an English chemist and physicist who contributed to the study of electrochemistry and electromagnetism. His main discoveries include the principles underlying electromagnetic inducti ...

.Mohamed A. El-Sharkawi, ''Electric Energy: An Introduction, Third Edition'', CRC Press, 2015, , page 3 Pixii's device was a spinning magnet, operated by a hand crank, where the north and south poles passed over a coil with an iron core, and thus classified as a magneto. A current pulse was produced each time a pole passed over the coil. He also found that the current direction changed when the north pole passed over the coil after the south pole. Later, acting on a suggestion by André-Marie Ampère, other results were obtained by introducing a

commutator In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory. Group theory The commutator of two elements, ...

which produced a pulsating

direct current Direct current (DC) is one-directional electric current, flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor (material), conductor such as a wire, but can also flow throug ...

. At that time direct current was preferable to alternating current. Although Pixii did not fully understand electromagnetic induction, his device led to more sophisticated devices being constructed. A reproduction of Pixii's electrical generator can be admired at the Ampère Museum, close to Lyon.

References

19th-century French engineers People associated with electricity 1808 births 1835 deaths Engineers from Paris {{France-scientist-stub

See also

References