John Ambrose Fleming
Encyclopedia
Sir John Ambrose Fleming (29 November 1849 – 18 April 1945) was an English
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 is also famous for the left hand rule
(for electric motors). He was born the eldest of seven children of James Fleming DD (died 1879), a Congregational minister, and his wife, Mary Ann, at Lancaster, Lancashire
and baptized on 11 February 1850.
He was a devout Christian and preached on one occasion at St Martin-in-the-Fields
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
.
, London, and University College London
. He entered St John's College, Cambridge
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 Cambridge
, the University of Nottingham
, and University College London
, 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 London
.
. 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, London, 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 Kensington
in London (now Imperial College). 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 College
, a public school
, earning £400 per year. (He later also taught at Rossall School
.) His own scientific research continued and he corresponded with James Clerk Maxwell
at Cambridge University. 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 Cambridge
. 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 University as a demonstrator of mechanical engineering before being appointed as the first Professor
of Physics
and Mathematics
at the University of Nottingham
, 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 Bath. On 27 July 1928 he married the popular young singer Olive May Franks (b. 1898/9), of Bristol
, daughter of George Franks, a Cardiff
businessman.
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 London
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, London 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 1904, he invented the two-electrode vacuum-tube rectifier, which he called the oscillation valve, for which he received a patent on 16 November. It was also called a thermionic valve, vacuum diode
, kenotron, thermionic tube, or Fleming valve. The Supreme Court of the United States
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, London 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.
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 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 in an AC power
system. He was knighted
in 1929, and died at his home in Sidmouth
, Devon
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:
In the ensuing years, valves quickly superseded "cat’s whiskers" and were the main device used to create the huge electronics industry that we take for granted today. They remained dominant until the transistor took dominance in the early 1970s
Today, descendants of the original valve (or 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 some high-end audio amplifiers, as detectors of optical and short wavelength radiation, and in sensitive equipment that must be "radiation-hard".
In 1941 the London Power Company
commemorated Fleming by naming a new 1,555 GRT
coastal
collier
SS Ambrose Fleming.
On the 27th November 2004 a Blue Plaque
presented by the Institute of Physics was unveiled at the Norman Lockyer Observatory, Sidmouth
, to mark 100 years since the invention of the Thermionic Radio Valve.
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
electrical engineer and physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
. He is known for inventing the first thermionic valve or vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
, the diode
Diode
In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
, then called the kenotron in 1904. He is also famous for the left hand rule
Fleming's left hand rule for motors
Fleming's left-hand rule , and Fleming's right-hand rule are a pair of visual mnemonics that is used for working out the direction of motion in an electric motor, or the direction of electric current in an electric generator...
(for electric motors). He was born the eldest of seven children of James Fleming DD (died 1879), a Congregational minister, and his wife, Mary Ann, at Lancaster, Lancashire
Lancashire
Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston...
and baptized on 11 February 1850.
He was a devout Christian and preached on one occasion at St Martin-in-the-Fields
St Martin-in-the-Fields
St Martin-in-the-Fields is an Anglican church at the north-east corner of Trafalgar Square in the City of Westminster, London. Its patron is Saint Martin of Tours.-Roman era:Excavations at the site in 2006 led to the discovery of a grave dated about 410...
in London on the topic of evidence for the resurrection
Resurrection
Resurrection refers to the literal coming back to life of the biologically dead. It is used both with respect to particular individuals or the belief in a General Resurrection of the dead at the end of the world. The General Resurrection is featured prominently in Jewish, Christian, and Muslim...
. In 1932, along with Douglas Dewar
Douglas Dewar
Douglas Dewar was a barrister, British civil servant in India and an ornithologist. He wrote widely in newspapers such as The Madras Mail, Pioneer, Times of India and periodicals such as the Civil and Military Gazette and Bird Notes.-Biography:He particularly advanced field studies of birds and he...
and Bernard Acworth
Bernard Acworth
Captain Bernard Acworth was an English submariner, writer, evangelical Christian and creationist.-Biography:...
, 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
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
.
Early years
Ambrose Fleming was born in Lancaster and educated at University College SchoolUniversity College School
University College School, generally known as UCS, is an Independent school charity situated in Hampstead, north west London, England. The school was founded in 1830 by University College London and inherited many of that institution's progressive and secular views...
, London, and University College London
University College London
University College London is a public research university located in London, United Kingdom and the oldest and largest constituent college of the federal University of London...
. He entered St John's College, Cambridge
St John's College, Cambridge
St John's College is a constituent college of the University of Cambridge. The college's alumni include nine Nobel Prize winners, six Prime Ministers, three archbishops, at least two princes, and three Saints....
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 Cambridge
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...
, the University of Nottingham
University of Nottingham
The University of Nottingham is a public research university based in Nottingham, United Kingdom, with further campuses in Ningbo, China and Kuala Lumpur, Malaysia...
, and University College London
University College London
University College London is a public research university located in London, United Kingdom and the oldest and largest constituent college of the federal University of London...
, where he was the first professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
of Electrical Engineering. He was also consultant to the Marconi
Marconi Company
The Marconi Company Ltd. was founded by Guglielmo Marconi in 1897 as The Wireless Telegraph & Signal Company...
Wireless Telegraph Company, Swan Company, Ferranti
Ferranti
Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. Known primarily for defence electronics, the Company was once a constituent of the FTSE 100 Index but ceased trading in 1993.The...
, Edison Telephone, and later the Edison Electric Light Company. In 1892, Fleming presented an important paper on electrical transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
theory to the Institution of Electrical Engineers
Institution of Electrical Engineers
The Institution of Electrical Engineers was a British professional organisation of electronics, electrical, manufacturing, and Information Technology professionals, especially electrical engineers. The I.E.E...
in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
.
Education and marriages
Fleming started school at about the age of ten, attending a private school where he particularly enjoyed geometryGeometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
. 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
University College School
University College School, generally known as UCS, is an Independent school charity situated in Hampstead, north west London, England. The school was founded in 1830 by University College London and inherited many of that institution's progressive and secular views...
where, although accomplished at maths, he habitually came bottom of the class at Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
.
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, London, graduated in 1870, and studied under the mathematician Augustus de Morgan
Augustus De Morgan
Augustus De Morgan was a British mathematician and logician. He formulated De Morgan's laws and introduced the term mathematical induction, making its idea rigorous. The crater De Morgan on the Moon is named after him....
and the physicist George Carey Foster
Carey Foster
George Carey Foster was a chemist and physicist, born at Sabden in Lancashire,He was Professor of Physics at University College London.-Early life:...
. He became a student of chemistry at the Royal College of Science
Royal College of Science
The Royal College of Science was a higher education institution located in South Kensington; it was a constituent college of Imperial College London from 1907 until it was wholly absorbed by Imperial in 2002. Alumni include H. G. Wells and Brian May and are distinguishable by the letters ARCS ...
in South Kensington
South Kensington
South Kensington is a district in the Royal Borough of Kensington and Chelsea in London. It is a built-up area located 2.4 miles west south-west of Charing Cross....
in London (now Imperial College). There he first studied Alessandro Volta
Alessandro Volta
Count Alessandro Giuseppe Antonio Anastasio Gerolamo Umberto Volta was a Lombard physicist known especially for the invention of the battery in 1800.-Early life and works:...
'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
Physical Society of London
The Physical Society of London, England, existed from 1874 to 1921. It was a scientific society and produced the Proceedings of the Physical Society of London...
(now the Institute of Physics
Institute of Physics
The Institute of Physics is a scientific charity devoted to increasing the practice, understanding and application of physics. It has a worldwide membership of around 40,000....
) 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 College
Cheltenham College
Cheltenham College is a co-educational independent school, located in Cheltenham, Gloucestershire, England.One of the public schools of the Victorian period, it was opened in July 1841. An Anglican foundation, it is known for its classical, military and sporting traditions.The 1893 book Great...
, a public school
Public School (UK)
A public school, in common British usage, is a school that is neither administered nor financed by the state or from taxpayer contributions, and is instead funded by a combination of endowments, tuition fees and charitable contributions, usually existing as a non profit-making charitable trust...
, earning £400 per year. (He later also taught at Rossall School
Rossall School
Rossall School is a British, co-educational, independent school, between Cleveleys and Fleetwood, Lancashire. Rossall was founded in 1844 by St. Vincent Beechey as a sister school to Marlborough College which had been founded the previous year...
.) His own scientific research continued and he corresponded with James Clerk Maxwell
James Clerk Maxwell
James Clerk Maxwell of Glenlair was a Scottish physicist and mathematician. His most prominent achievement was formulating classical electromagnetic theory. This united all previously unrelated observations, experiments and equations of electricity, magnetism and optics into a consistent theory...
at Cambridge University. 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 Cambridge
Cambridge
The city of Cambridge is a university town and the administrative centre of the county of Cambridgeshire, England. It lies in East Anglia about north of London. Cambridge is at the heart of the high-technology centre known as Silicon Fen – a play on Silicon Valley and the fens surrounding the...
. 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 University as a demonstrator of mechanical engineering before being appointed as the first Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
of Physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
and Mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
at the University of Nottingham
University of Nottingham
The University of Nottingham is a public research university based in Nottingham, United Kingdom, with further campuses in Ningbo, China and Kuala Lumpur, Malaysia...
, 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 Bath. On 27 July 1928 he married the popular young singer Olive May Franks (b. 1898/9), of Bristol
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
, daughter of George Franks, a Cardiff
Cardiff
Cardiff is the capital, largest city and most populous county of Wales and the 10th largest city in the United Kingdom. The city is Wales' chief commercial centre, the base for most national cultural and sporting institutions, the Welsh national media, and the seat of the National Assembly for...
businessman.
Activities and achievements
After leaving the University of NottinghamUniversity of Nottingham
The University of Nottingham is a public research university based in Nottingham, United Kingdom, with further campuses in Ningbo, China and Kuala Lumpur, Malaysia...
in 1882, Fleming took up the post of "Electrician" to the Edison Electrical Light Company, advising on lighting systems and the new Ferranti
Ferranti
Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. Known primarily for defence electronics, the Company was once a constituent of the FTSE 100 Index but ceased trading in 1993.The...
alternating current systems. In 1884 Fleming joined University College London
University College London
University College London is a public research university located in London, United Kingdom and the oldest and largest constituent college of the federal University of London...
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, London and Fleming took up the Pender Chair
Pender Chair
The Pender Chair is the post that is generally held by the head of the Department of Electronic and Electrical Engineering of University College London....
after the £5000 was endowed as a memorial to John Pender
John Pender
Sir John Pender , British Submarine communications cable pioneer, was born in the Vale of Leven, Scotland, and after attending school in Glasgow became a successful merchant in textile fabrics in that city and in Manchester; where he had a warehouse in Peter street near The Great Northern Warehouse...
, the founder of Cable and Wireless. In 1899 Fleming became Scientific Advisor to the Marconi Company
Marconi Company
The Marconi Company Ltd. was founded by Guglielmo Marconi in 1897 as The Wireless Telegraph & Signal Company...
and soon after began work on the designing the power plant to enable the Marconi Company
Marconi Company
The Marconi Company Ltd. was founded by Guglielmo Marconi in 1897 as The Wireless Telegraph & Signal Company...
to transmit across the Atlantic.
In 1904, he invented the two-electrode vacuum-tube rectifier, which he called the oscillation valve, for which he received a patent on 16 November. It was also called a thermionic valve, vacuum diode
Diode
In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
, kenotron, thermionic tube, or Fleming valve. The Supreme Court of the United States
Supreme Court of the United States
The Supreme Court of the United States is the highest court in the United States. It has ultimate appellate jurisdiction over all state and federal courts, and original jurisdiction over a small range of cases...
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
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
, for this was the first vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
. Fleming's diode
Diode
In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
was used in radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
receivers and radars for many decades afterwards, until it was superseded by solid state
Solid state (electronics)
Solid-state electronics are those circuits or devices built entirely from solid materials and in which the electrons, or other charge carriers, are confined entirely within the solid material...
electronic technology more than 50 years later.
Fleming retired from University College, London in 1927 at the age of 77. He remained active, becoming a committed advocate of the new technology of Television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
which included servicing as the first president of the Television Society.
In 1906, Lee De Forest
Lee De Forest
Lee De Forest was an American inventor with over 180 patents to his credit. De Forest invented the Audion, a vacuum tube that takes relatively weak electrical signals and amplifies them. De Forest is one of the fathers of the "electronic age", as the Audion helped to usher in the widespread use...
of the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
added a control "grid" to the valve to create a vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
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
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
, a tube called the triode
Triode
A triode is an electronic amplification device having three active electrodes. The term most commonly applies to a vacuum tube with three elements: the filament or cathode, the grid, and the plate or anode. The triode vacuum tube was the first electronic amplification device...
. 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 many years with victories at different stages for both sides. Fleming also contributed in the fields of photometry
Photometry (optics)
Photometry is the science of the measurement of light, in terms of its perceived brightness to the human eye. It is distinct from radiometry, which is the science of measurement of radiant energy in terms of absolute power; rather, in photometry, the radiant power at each wavelength is weighted by...
, electronics
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
, wireless telegraphy
Wireless telegraphy
Wireless telegraphy is a historical term used today to apply to early radio telegraph communications techniques and practices, particularly those used during the first three decades of radio before the term radio came into use....
(radio), and electrical measurements. He coined the term Power Factor
Power factor
The power factor of an AC electric power system is defined as the ratio of the real power flowing to the load over the apparent power in the circuit, and is a dimensionless number between 0 and 1 . Real power is the capacity of the circuit for performing work in a particular time...
to describe the true power flowing in an AC power
AC power
Power in an electric circuit is the rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductance and capacitance may result in periodic reversals of the direction of energy flow...
system. He was knighted
British honours system
The British honours system is a means of rewarding individuals' personal bravery, achievement, or service to the United Kingdom and the British Overseas Territories...
in 1929, and died at his home in Sidmouth
Sidmouth
Sidmouth is a small town on the English Channel coast in Devon, South West England. The town lies at the mouth of the River Sid in the East Devon district, south east of Exeter. It has a population of about 15,000, of whom 40% are over 65....
, Devon
Devon
Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...
in 1945. His contributions to electronic communications and radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
were of vital importance in winning World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. Fleming was awarded the IRE Medal of Honor
IEEE Medal of Honor
The IEEE Medal of Honor is the highest recognition of the Institute of Electrical and Electronics Engineers . It has been awarded since 1917, when its first recipient was Major Edwin H. Armstrong. It is given for an exceptional contribution or an extraordinary career in the IEEE fields of...
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 frequencyHigh frequencyHigh frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very 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 triodeTriodeA triode is an electronic amplification device having three active electrodes. The term most commonly applies to a vacuum tube with three elements: the filament or cathode, the grid, and the plate or anode. The triode vacuum tube was the first electronic amplification device...
valve and many related structures, it can also be considered to be the device that gave birth to modern electronics.
In the ensuing years, valves quickly superseded "cat’s whiskers" and were the main device used to create the huge electronics industry that we take for granted today. They remained dominant until the transistor took dominance in the early 1970s
Today, descendants of the original valve (or 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 some high-end audio amplifiers, as detectors of optical and short wavelength radiation, and in sensitive equipment that must be "radiation-hard".
In 1941 the London Power Company
London Power Company
The London Power Company was an electricity generating and supply company in London, England. The LPC was formed in 1925 by the merger of 10 smaller electricity companies...
commemorated Fleming by naming a new 1,555 GRT
Gross Register Tonnage
Gross register tonnage a ship's total internal volume expressed in "register tons", one of which equals to a volume of . It is calculated from the total permanently enclosed capacity of the vessel. The ship's net register tonnage is obtained by reducing the volume of non-revenue-earning spaces i.e...
coastal
Coastal trading vessel
Coastal trading vessels, also known as coasters, are shallow-hulled ships used for trade between locations on the same island or continent. Their shallow hulls mean that they can get through reefs where deeper-hulled sea-going ships usually cannot....
collier
Collier (ship type)
Collier is a historical term used to describe a bulk cargo ship designed to carry coal, especially for naval use by coal-fired warships. In the late 18th century a number of wooden-hulled sailing colliers gained fame after being adapted for use in voyages of exploration in the South Pacific, for...
SS Ambrose Fleming.
On the 27th November 2004 a Blue Plaque
Blue plaque
A blue plaque is a permanent sign installed in a public place to commemorate a link between that location and a famous person or event, serving as a historical marker....
presented by the Institute of Physics was unveiled at the Norman Lockyer Observatory, Sidmouth
Sidmouth
Sidmouth is a small town on the English Channel coast in Devon, South West England. The town lies at the mouth of the River Sid in the East Devon district, south east of Exeter. It has a population of about 15,000, of whom 40% are over 65....
, 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)