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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were used in power supplies for electronic equipment and in high-current battery-charger applications until they were superseded by silicon diode rectifiers in the late 1960s.
While selenium rectifiers were lighter in weight and used less power than comparable vacuum tube rectifiers, they had the disadvantage of finite life expectancy, increasing resistance with age, and were only suitable to use at low frequencies. Both selenium and copper oxide rectifiers have somewhat better tolerance of momentary voltage ...
Selenium Rectifier. 8-plate 160V 450mA Federal-brand. A metal rectifier is an early type of semiconductor rectifier in which the semiconductor is copper oxide, germanium or selenium. They were used in power applications to convert alternating current to direct current in devices such as radios and battery chargers.
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).
In 1933, selenium rectifiers were invented. [2] Transistor technology dates back to 1947, with the invention of the point-contact transistor, which was followed by the bipolar junction transistor (BJT) in 1948. By the 1950s, higher power semiconductor diodes became available and started replacing vacuum tubes.
selenium rectifiers One type of metal rectifier, though selenium is considered a "metalloid" – formerly much used but now replaced by silicon semiconductors. semiconductor A substance with electrical conductivity between that of insulators and conductors; displays a negative temperature coefficient of resistance, and is also sensitive to light.
Credit - Photo-Illustration by TIME; Capelle.r/Getty Images; Artfully79/Getty Images. W hen the German philosopher Immanuel Kant puzzled over why nature looks beautiful to us, he considered the ...
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.