About William Duddell
William Du Bois Duddell was an English physicist and electrical engineer. His inventions include the moving coil oscillograph, as well as the thermo-ammeter and thermo-galvanometer. They created light using an electrical arc between two carbon electrodes. The sounds were created by instabilities in the current caused by the arc's negative resistance. This device, which became known as the "singing arc", was one of the first electronic oscillators and Plasma speakers. Although he was not the first to discover, as Hermann Theodor Simon published the phenomenon in 1898.
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