Vacuumtubes

Vacuumtubes

definition-an electron [|tube] from which almost all air or gas has been evacuated: formerly used extensively in [|radio] and electronics.

history-tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum. Vacuum tubes may be used for [|rectification], [|amplification], [|switching], or similar processing or creation of electrical [|signals]. Vacuum tubes rely on [|thermionic emission] of electrons from a hot [|filament] or //[|cathode]//, that then travel through a vacuum toward the [|anode] (commonly called the //plate//), which is held at a positive voltage relative to the cathode. Additional electrodes interposed between the cathode and anode can alter the [|current], giving the tube the ability to [|amplify] and [|switch].

past and future

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purpose- Vacuum tubes were critical to the development of electronic technology, which drove the expansion and commercialization of [|radio] communication and broadcasting, [|television], [|radar], [|sound reproduction], large [|telephone] networks, analog and digital [|computers], and industrial [|process control]. Although some of these applications had counterparts using earlier technologies, such as the [|spark gap transmitter] or [|mechanical computers], it was the invention of the [|triode] vacuum tube and its capability of electronic amplification that made these technologies widespread and practical.

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link-[|vacum tubes history]

refrences-google.com