Search results
Results From The WOW.Com Content Network
Sir John Ambrose Fleming FRS [1] (29 November 1849 – 18 April 1945) was an English electrical engineer and physicist who invented the first thermionic valve or vacuum tube, [2] designed the radio transmitter with which the first transatlantic radio transmission was made, and also established the right-hand rule used in physics.
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 wireless telegraphy. It was the first practical vacuum tube and the first thermionic diode, a vacuum tube whose purpose is ...
It was years later that John Ambrose Fleming applied the rectifying property of the Edison effect to detection of radio signals, as an improvement over the magnetic detector. Amplification by vacuum tube became practical only with Lee de Forest's 1907 invention of the three-terminal "audion" tube, a crude form of what was to become the triode.
British physicist John Ambrose Fleming, working for the British Wireless Telegraphy Company, discovered that the Edison effect could be used to detect radio waves. Fleming went on to develop a two-element thermionic vacuum tube diode called the Fleming valve (patented 16 November 1904).
Exploring ultra-cold phenomena (to 1908) James Dewar initiated research into electrical resistance at low temperatures. Dewar and John Ambrose Fleming predicted that at absolute zero, pure metals would become perfect electromagnetic conductors (though, later, Dewar altered his opinion on the disappearance of resistance, believing that there would always be some resistance).
Physicist John Ambrose Fleming pointed out that Lodge's lecture was a physics experiment, not a demonstration of telegraphic signaling. After radio communication was developed Lodge's lecture would become the focus of priority disputes over who invented wireless telegraphy (radio).
There is also a Fleming's left-hand rule (for electric motors). The appropriately handed rule can be recalled from the letter "g", which is in "right" and "generator". These mnemonics are named after British engineer John Ambrose Fleming, who invented them. An equivalent version of Fleming's right-hand rule is the left-hand palm rule.
16 November – English electrical engineer John Ambrose Fleming, working for Marconi, is awarded a United States patent for the Fleming valve, the first thermionic vacuum tube, a two-electrode diode, which he calls the oscillation valve. First radio transmission of music, at Graz, Austria. Births