The Full Wiki

More info on John Ambrose Fleming

John Ambrose Fleming: Map

  
  

Wikipedia article:

Map showing all locations mentioned on Wikipedia article:



Sir John Ambrose Fleming (29 November 1849 – 18 April 1945) was an Englishmarker electrical engineer and physicist. He is known for inventing the first thermionic valve or vacuum tube, the diode, then called the kenotron in 1904. He also invented the right-hand rule, used in mathematics and electronics. He was born the eldest of seven children of James Fleming DD (died 1879), a Congregational minister, and his wife, Mary Ann, at Lancastermarker, Lancashiremarker and baptized on 11 February 1850. He was a devout Christian and preached on one occasion at St Martin-in-the-Fieldsmarker in London on the topic of evidence for the resurrection. In 1932, along with Douglas Dewar and Bernard Acworth, he helped establish the Evolution Protest Movement. Having no children, he bequeathed much of his estate to Christian charities, especially those that helped the poor. He was an accomplished photographer and, in addition, he painted watercolours and enjoyed climbing in the Alps.

Early years

Ambrose Fleming was born in Lancastermarker and educated at University College School, London, and University College Londonmarker. He entered St John's College, Cambridgemarker in 1877, gaining his B.A. in 1881 and becoming a Fellow of St John's in 1883. He went on to Lecture at several universities including the University of Cambridgemarker, the University of Nottinghammarker, and University College Londonmarker, where he was the first professor of Electrical Engineering. He was also consultant to the Marconi Wireless Telegraph Company, Swan Company, Ferranti, Edison Telephone, and later the Edison Electric Light Company. In 1892, Fleming presented an important paper on electrical transformer theory to the Institution of Electrical Engineers in Londonmarker.

Education and marriages

Fleming started school at about the age of ten, attending a private school where he particularly enjoyed geometry. Prior to that his mother tutored him and he had learned, virtually by heart, a book called the Child's Guide to Knowledge, a popular book of the day — even as an adult he would quote from it. His schooling continued at the University College School where, although accomplished at maths, he habitually came bottom of the class at Latin.

Even as a boy he wanted to become an engineer. At 11 he had his own workshop where he built model boats and engines. He even built his own camera, the start of a lifelong interest in photography. Training to become an engineer was beyond the family's financial resources, but he reached his goal via a path that alternated education with paid employment.

He enrolled for a BSc degree at University College, Londonmarker, graduated in 1870, and studied under the mathematician Augustus de Morgan and the physicist George Carey Foster. He became a student of chemistry at the Royal College of Science in South Kensingtonmarker in London (now Imperial Collegemarker). There he first studied Alessandro Volta's battery, which became the subject of his first scientific paper. This was the first paper to be read to the new Physical Society of London (now the Institute of Physics) and appears on page one of volume one of their Proceedings. Financial problems again forced him to work for a living and in the summer of 1874 he became science master at Cheltenham Collegemarker, a public school, earning £400 per year. (He later also taught at Rossall Schoolmarker.) His own scientific research continued and he corresponded with James Clerk Maxwell at Cambridge Universitymarker. After saving £400, and securing a grant of £50 a year, in October 1877 at the age of 27, he once again enrolled as a student, this time at Cambridgemarker. Maxwell's lectures, he admitted, were difficult to follow. Maxwell, he said, often appeared obscure and had "a paradoxical and allusive way of speaking". On occasions Fleming was the only student at those lectures. Fleming again graduated, this time with a First Class Honours degree in chemistry and physics. He then obtained a DSc from London and served one year at Cambridge Universitymarker as a demonstrator of mechanical engineering before being appointed as the first Professor of Physics and Mathematics at the University of Nottinghammarker, but he left after less than a year.

On 11 June 1887 he married Clara Ripley (1856/7–1917), daughter of Walter Freake Pratt, a solicitor from Bathmarker. On 27 July 1928 he married the popular young singer Olive May Franks (b. 1898/9), of Bristolmarker, daughter of George Franks, a Cardiffmarker businessman.

Activities and achievements

After leaving the University of Nottinghammarker in 1882, Fleming took up the post of "Electrician" to the Edison Electrical Light Company, advising on lighting systems and the new Ferranti alternating current systems. In 1884 Fleming joined University College Londonmarker taking up the Chair of Electrical Technology, the first of its kind in England. Although this offered great opportunities, he recalls in his autobiography that the only equipment provided to him was a blackboard and piece of chalk. In 1897 the Pender Laboratory was founding at University College, Londonmarker and Fleming took up the Pender Chair after the £5000 was endowed as a memorial to John Pender, the founder of Cable and Wireless.. In 1899 Fleming became Scientific Advisor to the Marconi Company and soon after began work on the designing the power plant to enable the Marconi Company to transmit across the Atlantic.

In November 1904, he invented the two-electrode vacuum-tube rectifier, which he called the oscillation valve. He would later patent this invention. It was also called a thermionic valve, vacuum diode, kenotron, thermionic tube, or Fleming valve. The Supreme Court of the United Statesmarker later invalidated the patent because of an improper disclaimer and, additionally, maintained the technology in the patent was known art when filed. This invention is often considered to have been the beginning of electronics, for this was the first vacuum tube. Fleming's diode was used in radio receivers and radars for many decades afterwards, until it was superseded by solid state electronic technology more than 50 years later.

Fleming retired from University College, Londonmarker in 1927 at the age of 77. He remained active, becoming a committed advocate of the new technology of Television which included servicing as the first president of the Television Society.

In 1906, Lee De Forest of the U.S.marker added a control "grid" to the valve to create a vacuum tube RF detector called the Audion, leading Fleming to accuse him of copying his ideas. De Forest's device was shortly refined by him and Edwin H. Armstrong into the first electronic amplifier, a tube called the triode. The triode was vital in the creation of long-distance telephone and radio communications, radars, and early electronic digital computers (mechanical and electro-mechanical digital computers already existed using different technology). The court battle over these patents lasted for nearly many years with victories at different stages for both sides. Fleming also contributed in the fields of photometry, electronics, wireless telegraphy (radio), and electrical measurements. He coined the term Power Factor to describe the true power flowing an AC power system. He was knighted in 1929, and died at his home in Sidmouthmarker, Devonmarker in 1945. His contributions to electronic communications and radar were of vital importance in winning World War II. Fleming was awarded the IRE Medal of Honor in 1933 for "the conspicuous part he played in introducing physical and engineering principles into the radio art".

Note from eulogy at the Centenary celebration of the invention of the thermionic valve:

One century ago, in November 1904, John Ambrose Fleming FRS, Pender Professor at UCL, filed in Great Britain, for a device called the Thermionic Valve. When inserted together with a galvanometer, into a tuned electrical circuit, it could be used as a very sensitive rectifying detector of high frequency wireless currents, known as radio waves. It was a major step forward in the ‘wireless revolution’.
In November 1905, he patented the "Fleming Valve" ( ). As a rectifying diode, and forerunner to the triode valve and many related structures, it can also be considered to be the device that gave birth to modern electronics.

In the ensuing years such valves, were largely superseded by "cat’s whiskers", and decades later most electron tubes, as they became generically known, were gradually replaced by semiconductor diodes and transistors, which were significantly smaller, cheaper, and more reliable. In time and in turn, even these have been largely replaced by integrated circuits, better known as silicon chips.

Today, descendants of the original vacuum tube still play an important role in a range of applications. They can be found in the power stages of radio and television transmitters, in audio amplifiers, as detectors of optical and short wavelength radiation, and in sensitive equipment that must be "radiation-hard".

On the 27th November 2004 a Blue Plaque (presented by the Institute of Physics) was unveiled at the "Norman Lockyer Observatorymarker", Sidmouthmarker, to mark 100 years since the invention of the Thermionic Radio Valve.

Books by Fleming

  • Electric Lamps and Electric Lighting: A course of four lectures on electric illumination delivered at the Royal Institution of Great Britain (1894) 228 pages, ISBN 0548479377.
  • The Alternate Current Transformer in Theory and Practice "The Electrician" Printing and Publishing Company (1896)
  • Magnets and Electric Currents E. & F. N. Spon. (1898)
  • A Handbook for the Electrical Laboratory and Testing Room "The Electrician" Printing and Publishing Company (1901)
  • Waves and Ripples in Water, Air, and Aether MacMillan (1902).
  • The Evidence of Things Not Seen Christian Knowledge Society: London (1904)
  • The Principles of Electric Wave Telegraphy (1906), Longmans Green, London, 671 pages.
  • The Propagation of Electric Currents in Telephone and Telegraph Conductors (1908) Constable, 316 pages.
  • An Elementary Manual of Radiotelegraphy and Radiotelephony (1911) Longmans Green, London, 340 pages.
  • On the power factor and conductivity of dielectrics when tested with alternating electric currents of telephonic frequency at various temperatures (1912) Gresham, 82 pages, ASIN: B0008CJBIC
  • The Wonders of Wireless Telegraphy : Explained in simple terms for the non-technical reader Society for promoting Christian Knowledge (1913)
  • The Wireless Telegraphist's Pocket Book of Notes, Formulae and Calculations The Wireless Press (1915)
  • The Thermionic Valve and its Development in Radio Telegraphy and Telephony (1919).
  • Fifty Years of Electricity The Wireless Press (1921)
  • Electrons, Electric Waves and Wireless telephony The Wireless Press (1923)
  • Introduction to Wireless Telegraphy and Telephony Sir Isaac Pitman and Sons Ltd. (1924)
  • Mercury-arc Rectifiers and Mercury-vapour Lamps London. Pitman (1925)
  • The Electrical Educator (3 volumes), The New Era Publishing Co Ltd (1927)
  • Memories of a Scientific life Marshall, Morgan & Scott (1934)
  • Evolution or Creation? (1938) Marshall Morgan and Scott, 114 pages, ASIN: B00089BL7Y - outlines objections to Darwin.
  • Mathematics for Engineers George Newnes Ltd (1938)


References

  1. "IN SIR JOHN PENDER'S MEMORY.; Bust to be Erected and a Laboratory in London Endowed, New Your Times, June 27th, 1897"
  2. Fleming Valve patent
  3. "Misreading the Supreme Court: A Puzzling Chapter in the History of Radio". November 1998, Mercurians.org.
  • {{cite book |title=History of Wireless |last1=Mitchell |first1=John |last2=Griffiths |first2=Hugh |last3=Boyd |first3=Ian |editor1-first=Tapan |editor1-last=Sarkar |editor2-first=Robert |editor2-last=Mailloux |editor3-first=Arthur |editor3-last=Oliner |editor4-first=Magdalena |editor4-last=Salaza-Palma |editor5-first=Dipak |editor5-last=Sengupta |year=2006 |publisher=John Wiley & Sons |location=New Jersey |isbn=0-471-71814-9 |pages= 311-326} |ref=Sarkar06}}


External articles




Embed code:






Got something to say? Make a comment.
Your name
Your email address
Message