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An 8-plate 160 V 450 mA Federal brand selenium rectifier. A selenium rectifier is a type of metal rectifier, invented in 1933. [1] They were used in power supplies for electronic equipment and in high-current battery-charger applications until they were superseded by silicon diode rectifiers in the late 1960s.
Before the development of silicon semiconductor rectifiers, vacuum tube thermionic diodes and copper oxide- or selenium-based metal rectifier stacks were used. [1] The first vacuum tube diodes designed for rectifier application in power supply circuits were introduced in April 1915 by Saul Dushman of General Electric.
A number of rectifier discs would need to be used in series to provide an adequate reverse breakdown voltage figure – a bridge rectifier for a 12V battery charger would often use 12 metal rectifiers. Selenium rectifiers were generally more efficient than metal-oxide types, and could handle higher voltages.
A compound semiconductor is a semiconductor compound composed of chemical elements of at least two different species. These semiconductors form for example in periodic table groups 13–15 (old groups III–V), for example of elements from the Boron group (old group III, boron, aluminium, gallium, indium) and from group 15 (old group V, nitrogen, phosphorus, arsenic, antimony, bismuth).
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Selenium rectifier; Selenium yeast; Sibplaz; Willoughby Smith This page was last edited on 15 April 2021, at 14:35 (UTC). Text is available under the Creative ...
Selenium is found in metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells.
These selenium rectifiers were used (and are still used) to convert alternating current to direct current in electrical power applications. During 1925–1940, diodes consisting of a pointed tungsten metal wire in contact with a silicon crystal base, were fabricated in laboratories to detect microwaves in the UHF range.