Editing Rectifier (section)

== Rectifier devices ==
Before the development of silicon semiconductor rectifiers, vacuum tube [[thermionic diode]]s and copper oxide- or selenium-based [[metal rectifier]] stacks were used.<ref>{{cite book|url = https://books.google.com/books?id=rslXJmYPjGIC&pg=PA18|page=18|title = A History of the World Semiconductor Industry|isbn = 978-0-86341-227-1|last1 = Morris|first1 = Peter Robin|year = 1990}}</ref> The first vacuum tube diodes designed for rectifier application in power supply circuits were introduced in April 1915 by [[Saul Dushman]] of General Electric.<ref>Dushman, S. (1915). [https://archive.org/details/generalelectricr18gene/page/156/mode/2up?view=theater "A New Device for Rectifying High Tension Alternating Currents - The Kenotron"] ''General Electric Review'' pp. 156 - 167. Retrieved Nov. 2021</ref><ref>Dushman, S. (1915). [https://patentimages.storage.googleapis.com/8a/93/b3/2b97df34eaf78e/US1287265.pdf ''Electrical Discharge Device'']. U. S. patent 1,287,265. Retrieved Nov. 2021.</ref> With the introduction of semiconductor electronics, vacuum tube rectifiers became obsolete, except for some enthusiasts of vacuum tube [[audio equipment]]. For power rectification from very low to very high current, semiconductor diodes of various types ([[junction diode]]s, [[Schottky diode]]s, etc.) are widely used.

Other devices that have control electrodes as well as acting as unidirectional current valves are used where more than simple rectification is required—e.g., where variable output voltage is needed. High-power rectifiers, such as those used in [[high-voltage direct current]] power transmission, employ silicon semiconductor devices of various types. These are [[thyristor]]s or other controlled switching solid-state switches, which effectively function as diodes to pass current in only one direction.