Pixii, Hippolyte (1808–1835)

French inventor who in 1832 made the first practical electricity generator. It could produce both direct current and alternating current.

Pixii was an instrumentmaker, trained by his father. Learning of Michael Faraday's electromagnetic induction and his suggestions for making a simple dynamo, Pixii constructed a device that consisted of a permanent horseshoe magnet, rotated by means of a treadle, and a coil of copper wire above each of the magnet's poles. The two coils were linked and the free ends of the wires connected to terminals, from which a small alternating current was obtained when the magnet rotated. This device was first exhibited at the French Academy of Sciences in Paris 1832. Later, at the suggestion of physicist André Marie Ampère, a commutator (a simple switching device for reversing the connections to the terminals as the magnet is rotated) was fitted so that Pixii's generator could produce direct-current electricity. This revised generator was taken to Britain in 1833 and exhibited in London.