John Ambrose Fleming

Sir John Ambrose Fleming ( born November 29, 1849 in Lancaster, Lancashire, † April 18, 1945 in Sidmouth, Devon ), sometimes also called Ambrose J. Fleming, was a British electrical engineer and physicist. His parents were James and Mary Anne Fleming, John had six younger siblings.

Life and work

John Ambrose Fleming was educated at University College School in London and University College London. He worked as a lecturer at various universities, including the University of Cambridge, the University of Nottingham and University College London. Fleming was an advisor to the company Marconi Wireless Telegraph Company, Swan, Ferranti, Edison Telephone and later the Edison Electric Light Company. In 1892 he laid the Institution of Electrical Engineers in London before an important work on the theory of the transformer.

On November 16, 1904 Fleming applied for a patent in England, entitled "Improvements in Instruments for Detecting and Measuring Alternating Electric Currents ", in which he described a " two-electrode radio rectifier ". Looking for a better detector of radio waves he had discovered that the Edison effect could be used for the detection of signals.

He called his invention Oscillation Valve ( " oscillation valve "). The patent number GB190424850 was awarded to him on 21 November 1905. His invention was also known by the name Kenotron, electron valve, vacuum diode, electron tube, or Fleming valve. In many cases, this invention is considered to be the beginning of the electronic age.

1906 developed the American inventor Lee de Forest from an as Audion ( triode) designated amplifying high frequency tube detector by adding a control grid as a third electrode. This meant that Fleming accused him of imitation. De Forest's triode was later used to amplify electrical signals.

Fleming made ​​contributions in the fields of photometry, wireless telegraphy and electrical measurements. In 1929 he was knighted in 1933 and received the Ehrenmedailie (IRE Medal of Honor ) of the Institute of Radio Engineers (IRE ).