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Later thermionic vacuum tubes, mostly miniature style, some with top cap connections for higher voltages. A vacuum tube, electron tube, [1] [2] [3] thermionic valve (British usage), or tube (North America) [4] is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
A vacuum-tube computer, now termed a first-generation computer, is a computer that uses vacuum tubes for logic circuitry. While the history of mechanical aids to computation goes back centuries, if not millennia, the history of vacuum tube computers is confined to the middle of the 20th century. Lee De Forest invented the triode in 1906. The ...
A Curristor vacuum tube that had four types of nitrogen-filled, radioactive constant-current tubes with a current plateau from 25 to 500 V, all-glass wire-ended, active material is 226Ra with a half-life of 1601 years, for linear capacitor charging and draining in missile and ordinance mine timing circuits, instrumentation biasing, as current ...
The first prototype Fleming valves, built October 1904. Early commercial Fleming valves used in radio receivers, 1919 Fleming valve schematic from US Patent 803,684.. The Fleming valve, also called the Fleming oscillation valve, was a thermionic valve or vacuum tube invented in 1904 by English physicist John Ambrose Fleming as a detector for early radio receivers used in electromagnetic ...
One of the most significant consequences of Geissler tube technology was the discovery of the electron and the invention of electronic vacuum tubes. By the 1870s better vacuum pumps enabled scientists to evacuate Geissler tubes to a higher vacuum; these were called Crookes tubes after William Crookes. When current was applied, it was found that ...
Machlett Laboratories was a Northeastern United States-based company that manufactured X-ray and high-power vacuum tubes. Machlett was a large producer of the tubes and developed accessories to be used with them as well. For its contributions to World War II efforts, the US government gave it an "E" award in 1945.
In modern electronics, the vacuum tube has been largely superseded by solid state devices such as the transistor, invented in 1947 and implemented in integrated circuits in 1959, although vacuum tubes remain to this day in such applications as high-powered transmitters, guitar amplifiers and some high fidelity audio equipment. Application images
Johann Heinrich Wilhelm Geißler (26 May 1814 in Igelshieb – 24 January 1879) was a skilled glassblower and physicist, famous for his invention of the hand pumped Geissler mercury vacuum pump in the mid-1850's and in 1857, the Geissler tube, made of glass and used as a low pressure gas-discharge tube; these two inventions were critical ...