Fleming valve schematic from US Patent 803,684. The Fleming valve, also called the Fleming oscillation valve, was a vacuum tube diode invented by John Ambrose Fleming and used in the earliest days of radio communication. As the first vacuum tube, the IEEE has described it as "one of the most important developments in the history of electronics",[1] and it is on the List of IEEE Milestones for electrical engineering. Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ...
Types of diodes closeup, showing germanium crystal In electronics, a diode is a component that restricts the direction of movement of charge carriers. ...
Sir John Ambrose Fleming (), (November 29, 1849 - April 18, 1945) was an English electrical engineer and physicist. ...
Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ...
The Institute of Electrical and Electronics Engineers or IEEE (pronounced as eye-triple-ee) is an international non-profit, professional organization incorporated in the State of New York, United States. ...
Electrical Engineers design power systems… … and complex electronic circuits. ...
Description
Applications The Fleming valve was the first practical application of the "Edison effect" (thermionic emission) discovered in 1883 by Thomas Edison shortly after his invention of the incandescent light bulb, that is, the emission of electrons by a lamp's heated filament to a nearby metal plate. Edison was granted a patent for this device as part of an electrical indicator in 1884, but did not hit upon any practical use. Professor Fleming of University College London consulted for the Edison Electric Light Company from 1881-1891, and subsequently for the Marconi Wireless Telegraph Company. Thermionic emission is the flow of electrons from a metal or metal oxide surface, caused by thermal vibrational energy overcoming the electrostatic forces holding electrons to the surface. ...
Thermionic emission (archaically known as the Edison effect) is the flow of electrons from a metal or metal oxide surface, caused by thermal vibrational energy overcoming the electrostatic forces holding electrons to the surface. ...
Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman who developed many devices which greatly influenced life around the world, including the phonograph and a long lasting light bulb. ...
An incandescent lamp bulb and its glowing filament. ...
University College London, commonly known as UCL, is a college of the University of London. ...
The General Electric Company, or GE, NYSE: GE is a multinational technology and services company. ...
An employee of the Marconi Company, England, 1906 The Marconi Company Ltd. ...
In 1901 Fleming designed a transmitter for Guglielmo Marconi to attempt transmission of radio waves across the Atlantic from Poldhu, England, to Nova Scotia, Canada. The distance between the two points was about 3,500 kilometres (2,100 miles). Although widely heralded as a great scientific advance, there was also some skepticism about this claim, in part because the signals had only been heard faintly and sporadically. In addition, there was no independent confirmation of the reported reception, and the transmission, which merely consisted of the three dots of the Morse code letter S sent repeatedly, came from a transmitter whose signals were difficult to differentiate from the noise made by atmospheric static discharges. (A detailed technical review of the early transatlantic work appears in John S. Belrose's work of 1995.)[2] The receptions of signals were difficult to detect with a galvanometer. Fleming researched on a way that he could get the received signal to flow in only one direction, its oscillations could be detected with less trouble.[3][4][5] Guglielmo Marconi, Marchese, GCVO (25 April 1874-20 July 1937) was an Italian inventor, best known for his development of a radiotelegraph system, which served as the foundation for the establishment of numerous affiliated companies worldwide. ...
Poldhu is a small area in south Cornwall, UK, situated on the Lizard Peninsula it comprises Poldhu Point and Poldhu Cove. ...
Motto (French) God and my right Anthem No official anthem - the United Kingdom anthem God Save the Queen is commonly used England() – on the European continent() – in the United Kingdom() Capital (and largest city) London (de facto) Official languages English (de facto) Unified - by Athelstan 927 AD Area - Total 130...
Motto: Munit Haec et Altera Vincit(Latin) One defends and the other conquers Capital Halifax Largest city Halifax Regional Municipality Official languages English Government - Lieutenant-Governor Mayann E. Francis - Premier Rodney MacDonald (PC) Federal representation in Canadian Parliament - House seats 11 - Senate seats 10 Confederation July 1, 1867 (1st) Area...
It has been suggested that Tangent galvanometer be merged into this article or section. ...
In 1904 Fleming tried an Edison effect bulb for this purpose, and found that it worked well to rectify high frequency oscillations and thus allow detection of the rectified signals by a galvanometer. On November 16, 1904, he applied for a US patent for what he termed an oscillation valve. This patent was subsequently issued as number 803,684 and found immediate utility in the detection of messages sent by Morse code. It has been suggested that Tangent galvanometer be merged into this article or section. ...
Oscillation valves The Fleming valve proved to be the start of a technological revolution. After reading Fleming's 1905 paper on his oscillation valve, American engineer Lee DeForest in 1906 created a three-element vacuum tube (the Audion) by adding a modulation grid. It could act as an amplifier and oscillator as well as detector. De Forest quickly refined his device into the triode, which was then central to the creation of long-distance telephone and radio communications, radars, and early digital computers. Similarities and differences between the Fleming valve and DeForest's triode caused decades of expensive and disruptive litigation, which were not settled until 1943 when the United States Supreme Court ruled Fleming's patent invalid.[6] Lee De Forest Lee De Forest, (August 26, 1873 - June 30, 1961), was an American inventor with over 300 patents to his name. ...
The Audion is an electronic amplifier device invented by Lee De Forest in 1906, the forerunner of what is generally known as a triode today, in which the flow of current from the filament to the plate was controlled by a third element, the grid. ...
Simplified diagram of a triode. ...
This article or section includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ...
This long range radar antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll. ...
The Supreme Court Building, Washington, D.C. The Supreme Court Building, Washington, D.C., (large image) The Supreme Court of the United States, located in Washington, D.C., is the highest court (see supreme court) in the United States; that is, it has ultimate judicial authority within the United States...
References and notes
Citations - ^ IEEE History Center: Fleming Valve, 1904
- ^ Fessenden and Marconi: Their Differing Technologies and Transatlantic Experiments During the First Decade of this Century
- ^ Radio Communications: A Brief Synopsis
- ^ John Ambrose Fleming (1849-1945) By W A Atherton, Published in Wireless World August 1990
- ^ Do note that Nikola Tesla had already discovered that oscillations, damped or undamped, could be detected after being made to flow one direction or being developed as alternating in direction. For more, see "Nikola Tesla on His Work With Alternating Currents and Their Application to Wireless Telegraphy, Telephony and Transmission of Power : An Extended Interview". ISBN 1893817016
- ^ The Supreme Court invalidated the patent because of an improper disclaimer and later maintained the technology in the patent was known art when filed. For more see, Misreading the Supreme Court: A Puzzling Chapter in the History of Radio. Mercurians.org.
Nikola Tesla (1856-1943)[1] was a world-renowned Serbian inventor, physicist, mechanical engineer and electrical engineer. ...
Patents - Issued
- U.S. Patent 803,684 - Instrument for converting alternating electric currents into continuous currents (Fleming valve patent)
- Cited by
- U.S. Patent 1,290,438 , Jan 7, 1910 : Fleming valve improvement by R. A. Weagant
- U.S. Patent 954,619 , Apr 12, 1910 : John Ambrose Fleming patent
- U.S. Patent 1,379,706 , Mar 10, 1917 : Fleming valve improvement by R. A. Weagant
- U.S. Patent 1,252,520 , Jan 8, 1918 : Fleming valve improvement by R. A. Weagant
- U.S. Patent 1,278,535 , Sep 10, 1918 : Fleming valve improvement by R. A. Weagant
- U.S. Patent 1,289,981 , Dec 31, 1918 : Fleming valve improvement by R. A. Weagant
- U.S. Patent 1,306,208 , Jun 10, 1919 : Fleming valve circuit improvement by R. A. Weagant
- U.S. Patent 1,338,889 , May 4, 1920 : Fleming valve improvement by R. A. Weagant
- U.S. Patent 1,347,894 , Jul 27, 1920 : Inverter converter by L. W. Chubb
- U.S. Patent 1,380,206 , May 31, 1921 : Fleming valve improvement by R. A. Weagant
- U.S. Patent RE16,363 , Jun 15, 1926 : Inverter converter by L. W. Chubb
- U.S. Patent 1,668,060 , May 1, 1928 : Fleming valve circuit improvement by P. E. Edelman
- U.S. Patent 2,472,760 , Jun 7, 1949 : Electrode improvement by H. L. Ratchford
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