Ignitron

Ignitron is the name for a controllable via an ignition electrode mercury-vapor rectifier mercury pool electrode. It was developed in the 1930s by Joseph Slepian at Westinghouse Electric Corporation.

The ignitron is composed of a metal container which is filled in the lower area with mercury. This metal container also represents the cathode terminal dar. In the upper part is separated by an insulator from the metal vessel, taken in the massive anode made ​​of graphite. About an ignition electrode ( Ignitor ) in the lower part can be triggered inside the ionization of mercury vapor. The ignition timing can be variable, which allows simple regulation. A Ignitron thus represents represents a variable in the power mercury arc rectifiers

Due to the special construction ignitrons currents can rectify to some 100,000 A and thus especially suitable in applications where very high DC currents are needed, such as fused-salt electrolysis. Ignitrons were used until the 1960s for the realization of phase control at power rectifiers. They were now almost completely replaced by thyristors.