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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were used in power supplies for electronic equipment and in high-current battery-charger applications until they were superseded by silicon diode rectifiers in the late 1960s.
Selenium is a chemical ... The development of selenium rectifiers began during the early ... At levels of 1 mg/m 3, selenium is immediately dangerous to life and ...
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.
Both selenium and copper oxide rectifiers have somewhat better tolerance of momentary voltage transients than silicon rectifiers. Typically these rectifiers were made up of stacks of metal plates or washers, held together by a central bolt, with the number of stacks determined by voltage; each cell was rated for about 20 V.
These elements include vanadium, manganese, iron, cobalt, copper, zinc, selenium, strontium and molybdenum. [75] A deficiency of these essential metals may increase susceptibility to heavy metal poisoning. [76] Selenium is the most toxic of the heavy metals that are essential for mammals. [77]
Selenium is a nutrient that is naturally present in many foods, added to others and is also available as a dietary supplement in pill, powder and liquid form, explains Perri Halperin, a ...
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).
It feels like the skies are becoming more dangerous. But sometimes feelings can be deceiving. A look at the statistics suggests that the skies are about as friendly as they’ve ever been.