Editing Ignitron (section)

[[Image:Ignitron.svg|right|thumb|250px|(1) Anode, (2) Cathode, (3) Ignitor, (4) Mercury, (5) Ceramic insulators, (6) Cooling fluid]]
An '''ignitron''' is a type of [[gas-filled tube]] used as a controlled [[rectifier]] and dating from the 1930s. Invented by [[Joseph Slepian]] while employed by [[Westinghouse Electric Corporation|Westinghouse]], Westinghouse was the original manufacturer and owned trademark rights to the name "Ignitron". Ignitrons are closely related to [[mercury-arc valve]]s but differ in the way the arc is ignited.  They function similarly to [[thyratron]]s; a triggering pulse to the igniter [[electrode]] turns the device "on", allowing a high current to flow between the [[cathode]] and [[anode]] electrodes.  After it is turned on, the current through the anode must be reduced to zero to restore the device to its nonconducting state.  They are used to switch high currents in heavy industrial applications.