-
1 Bell Telephone Laboratories
Общая лексика: телефонные лаборатории фирмы Белл (США)Универсальный англо-русский словарь > Bell Telephone Laboratories
-
2 Bell Telephone Laboratories
Abbreviation: BTLУниверсальный русско-английский словарь > Bell Telephone Laboratories
-
3 Bell telephone laboratories
-
4 BTL Bell Telephone Laboratories
Англо-русский словарь Мюллера > BTL Bell Telephone Laboratories
-
5 Bell Laboratories
"Белл лэбраториз"Исследовательский центр компании "Белл телефон" [ Bell Telephone Co.]. Исследования ведутся в области акустики, физики твердого тела, электроники, физической и органической химии и в ряде других областей. Находятся в г. Нью-Йорке.English-Russian dictionary of regional studies > Bell Laboratories
-
6 bell
bell [bel]1 noun(a) (in church) cloche f; (handheld) clochette f; (on bicycle) sonnette f; (for cows) cloche f, clarine f; (on boots, toys) grelot m; (sound) coup m (de cloche);∎ there goes the dinner bell c'est la cloche qui annonce le dîner;∎ Religion has the first bell for vespers gone? a-t-on sonné le premier coup des vêpres?;∎ Nautical to sound bells piquer la cloche ou l'heure;∎ Nautical it sounded four/eight bells cela a piqué quatre/huit coups (de cloche);∎ saved by the bell! sauvé par le gong!;∎ Religion bell, book and candle instruments mpl du culte;∎ bells and whistles accessoires mpl(b) (electrical device → on door) sonnette f;∎ there's the bell il y a quelqu'un à la porte, on sonne (à la porte);∎ to ring the bell sonner∎ to give sb a bell passer un coup de fil à qn(b) (bloat, distend) ballonner∎ figurative to bell the cat attacher le grelot►► Nautical bell buoy bouée f à cloche;American bell captain chef m chasseur;Horticulture bell glass cloche f de verre;Botany bell heather bruyère f cendrée;Chemistry bell jar cloche f de verre;Bell Laboratories, Bell Labs = centre américain de recherches scientifiques et techniques de haute renommée;bell push bouton m de sonnette;bell tent tente f conique;bell tower clocher mⓘ The bells, the bells Dans The Hunchback of Notre-Dame, la traduction anglaise de Notre-Dame de Paris de Victor Hugo, Quasimodo s'exclame "the bells, the bells!" lorsqu'il entend sonner les cloches de la cathédrale. Pour plaisanter, il arrive que l'on prononce ces paroles en prenant une grosse voix lorsque l'on entend sonner des cloches, pour évoquer le personnage de Quasimodo. -
7 Bellovi laboratoriji
-
8 BTL
компания «Белл Телефон Лабораториз» ( США) -
9 Bode, Hendrik Wade
[br]b. 24 December 1905 Madison, Wisconsin, USAd. 21 June 1982 Cambridge, Massachusetts, USA[br]American engineer who developed an extensive theoretical understanding of the behaviour of electronic circuits.[br]Bode received his bachelor's and master's degrees from Ohio State University in 1924 and 1926, respectively, and his PhD from Columbia University, New York, in 1935. In 1926 he joined the Bell Telephone Laboratories, where he made many theoretical contributions to the understanding of the behaviour of electronic circuits and, in particular, in conjunction with Harry Nyquist, of the conditions under which amplifier circuits become unstable.During the Second World War he worked on the design of gun control systems and afterwards was a member of a team that worked with Douglas Aircraft to develop the Nike anti-aircraft missile. A member of the Bell Laboratories Mathematical Research Group from 1929, he became its Director in 1952, and then Director of Physical Sciences. Finally he became Vice-President of the Laboratories, with responsibility for systems engineering, and a director of Bellcomm, a Bell company involved in the Moon-landing programme. When he retired from Bell in 1967, he became Professor of Systems Engineering at Harvard University.[br]Principal Honours and DistinctionsPresidential Certificate of Merit 1946. Institute of Electrical and Electronics Engineers Edison Medal 1969.Bibliography1940, "Relation between attenuation and phase in feedback amplifier design", Bell System Technical Journal 19:421.1945, Network Analysis and Feedback Amplifier Design, New York: Van Nostrand.1950, with C.E.Shannon, "A simplified derivation of linear least squares smoothing and prediction theory", Proceedings of the Institute of Radio Engineers 38:417.1961, "Feedback. The history of an idea", Proceedings of the Symposium on Active Networks and Feedback Systems, Brooklyn Polytechnic.1971, Synergy: Technical Integration and Technical Innovation in the Bell System Bell Laboratories, Bell Telephone Laboratories (provides background on his activities at Bell).Further ReadingP.C.Mahon, 1975, Mission Communications, Bell Telephone Laboratories. See also Black, Harold Stephen; Shannon, Claude Elwood.KF -
10 Colpitts, Edwin Henry
[br]b. 9 January 1872 Pointe de Bute, Canadad. 6 March 1949 Orange, New Jersey, USA[br]Canadian physicist and electrical engineer responsible for important developments in electronic-circuit technology.[br]Colpitts obtained Bachelor's degrees at Mount Allison University, Sackville, New Brunswick, and Harvard in 1894 and 1896, respectively, followed by a Master's degree at Harvard in 1897. After two years as assistant to the professor of physics there, he joined the American Bell Telephone Company. When the Bell Company was reorganized in 1907, he moved to the Western Electric branch of the company in New York as Head of the Physical Laboratories. In 1911 he became a director of the Research Laboratories, and in 1917 he became Assistant Chief Engineer of the company. During this time he invented both the push-pull amplifier and the Colpitts oscillator, both major developments in communications. In 1917, during the First World War, he spent some time in France helping to set up the US Signal Corps Research Laboratories. Afterwards he continued to do much, both technically and as a manager, to place telephone communications on a firm scientific basis, retiring as Vice-President of the Bell Telephone Laboratories in 1937. With the outbreak of the Second World War in 1941 he was recalled from retirement and appointed Director of the Engineering Foundation to work on submarine warfare techniques, particularly echo-ranging.[br]Principal Honours and DistinctionsOrder of the Rising Sun, Japan, 1938. US Medal of Merit 1948.Bibliography1919, with E.B.Craft, "Radio telephony", Proceedings of the American Institution of Electrical Engineers 38:337.1921, with O.B.Blackwell, "Carrier current telephony and telegraphy", American Institute of Electrical Engineers Transactions 40:205.11 September 1915, US reissue patent no. 15,538 (control device for radio signalling).28 August 1922, US patent no. 1,479,638 (multiple signal reception).Further ReadingM.D.Fagen, 1975, A History of Engineering \& Science in the Bell System, Vol. 1, Bell Laboratories.See also: Hartley, Ralph V.L.KF -
11 Keller, Arthur
[br]b. 18 August 1901 New York City, New York, USA d. 1983[br]American engineer and developer of telephone switching equipment who was instrumental in the development of electromechanical recording and stereo techniques.[br]He obtained a BSc in electrical engineering at Cooper Union for the Advancement of Science and Art, New York, in 1923 and an MSc from Yale University, and he did postgraduate work at Columbia University. Most of the time he was also on the staff of the Bell Telephone Laboratories. The Bell Laboratories and its predecessors had a long tradition in research in speech and hearing, and in a team of researchers under H.C. Harrison, Keller developed a number of definite improvements in electrical pick-ups, gold-sputtering for matrix work and electrical disc recording equipment. From 1931 onwards the team at Bell Labs developed disc recording for moving pictures and entered into collaboration with Leopold Stokowski and the Philadelphia Orchestra concerning transmission and recording of high-fidelity sound over wires, and stereo techniques. Keller developed a stereo recording system for disc records independently of A.D. Blumlein that was used experimentally in the Bell Labs during the 1930s. During the Second World War Keller was in a team developing sonar (sound navigation and ranging) for the US Navy. After the war he concentrated on switching equipment for telephone exchanges and developed a miniature relay. In 1966 he retired from the Bell Laboratories, where he had been Director of several departments, ending as Director of the Switching Apparatus Laboratory. After retirement he was a consultant internationally, concerning electromechanical devices in particular. When, in 1980, the Bell Laboratories decided to issue LP re-recordings of a number of the experimental records made during the 1930s, Keller was brought in from retirement to supervise the project and decide on the selections.[br]BibliographyKeller was inventor or co-inventor of forty patents, including: US patent no. 2,114,471 (the principles of stereo disc recording); US patent no. 2,612,586 (tape guides with air lubrication); US patent no. 3,366,901 (a miniature crossbar switch).Apart from a large number of highly technical papers, Keller also wrote the article "Phonograph" in the 1950 and 1957 editions of Encyclopaedia Britannica.1986, Reflections of a Stereo Pioneer, San Francisco: San Francisco Press (an honest, personal account).GB-N -
12 Nyquist, Harry
[br]b. 7 February 1889 Nilsby, Swedend. 4 April 1976 Texas, USA[br]Swedish-American engineer who established the formula for thermal noise in electrical circuits and the stability criterion for feedback amplifiers.[br]Nyquist (original family name Nykvist) emigrated from Sweden to the USA when he was 18 years old and settled in Minnesota. After teaching for a time, he studied electrical engineering at the University of North Dakota, gaining his first and Master's degrees in 1915 and 1916, and his PhD from Yale in 1917. He then joined the American Telegraph \& Telephone Company, moving to its Bell Laboratories in 1934 and remaining there until his retirement in 1954. A prolific inventor, he made many contributions to communication engineering, including the invention of vestigial-side band transmission. In the late 1920s he analysed the behaviour of analogue and digital signals in communication circuits, and in 1928 he showed that the thermal noise per unit bandwidth is given by 4 kT, where k is Boltzmann's constant and T the absolute temperature. However, he is best known for the Nyquist Criterion, which defines the conditions necessary for the stable, oscillation-free operation of amplifiers with a closed feedback loop. The problem of how to realize these conditions was investigated by his colleague Hendrik Bode.[br]Principal Honours and DistinctionsFranklin Institute Medal 1960. Institute of Electrical and Electronics Engineers Medal of Honour 1960; Mervin J.Kelly Award 1961.Bibliography1924, "Certain factors affecting telegraph speed", Bell System Technical Journal 3:324. 1928, "Certain topics in telegraph transmission theory", Transactions of the AmericanInstitute of Electrical Engineers 47:617.1928, "Thermal agitation of electric charge in conductors", Physical Review 32:110. 1932, "Regeneration theory", Bell System Technical Journal 11:126.1940, with K.Pfleger, "Effect of the quadrature component in single-sideband transmission", Bell System Technical Journal 19:63.Further ReadingBell Telephone Laboratories, 1975, Mission Communications.See also: Shannon, Claude ElwoodKF -
13 Pierce, John Robinson
[br]b. 27 March 1910 Des Moines, Iowa, USA[br]American scientist and communications engineer said to be the "father" of communication satellites.[br]From his high-school days, Pierce showed an interest in science and in science fiction, writing under the pseudonym of J.J.Coupling. After gaining Bachelor's, Master's and PhD degrees at the California Institute of Technology (CalTech) in Pasadena in 1933, 1934 and 1936, respectively, Pierce joined the Bell Telephone Laboratories in New York City in 1936. There he worked on improvements to the travelling-wave tube, in which the passage of a beam of electrons through a helical transmission line at around 7 per cent of the speed of light was made to provide amplification at 860 MHz. He also devised a new form of electrostatically focused electron-multiplier which formed the basis of a sensitive detector of radiation. However, his main contribution to electronics at this time was the invention of the Pierce electron gun—a method of producing a high-density electron beam. In the Second World War he worked with McNally and Shepherd on the development of a low-voltage reflex klystron oscillator that was applied to military radar equipment.In 1952 he became Director of Electronic Research at the Bell Laboratories' establishment, Murray Hill, New Jersey. Within two years he had begun work on the possibility of round-the-world relay of signals by means of communication satellites, an idea anticipated in his early science-fiction writings (and by Arthur C. Clarke in 1945), and in 1955 he published a paper in which he examined various possibilities for communications satellites, including passive and active satellites in synchronous and non-synchronous orbits. In 1960 he used the National Aeronautics and Space Administration 30 m (98 1/2 ft) diameter, aluminium-coated Echo 1 balloon satellite to reflect telephone signals back to earth. The success of this led to the launching in 1962 of the first active relay satellite (Telstar), which weighed 170 lb (77 kg) and contained solar-powered rechargeable batteries, 1,000 transistors and a travelling-wave tube capable of amplifying the signal 10,000 times. With a maximum orbital height of 3,500 miles (5,600 km), this enabled a variety of signals, including full bandwidth television, to be relayed from the USA to large receiving dishes in Europe.From 1971 until his "retirement" in 1979, Pierce was Professor of Electrical Engineering at CalTech, after which he became Chief Technologist at the Jet Propulsion Laboratories, also in Pasadena, and Emeritus Professor of Engineering at Stanford University.[br]Principal Honours and DistinctionsInstitute of Electrical and Electronics Engineers Morris N.Liebmann Memorial Award 1947; Edison Medal 1963; Medal of Honour 1975. Franklin Institute Stuart Ballantine Award 1960. National Medal of Science 1963. Danish Academy of Science Valdemar Poulsen Medal 1963. Marconi Award 1974. National Academy of Engineering Founders Award 1977. Japan Prize 1985. Arthur C.Clarke Award 1987. Honorary DEng Newark College of Engineering 1961. Honorary DSc Northwest University 1961, Yale 1963, Brooklyn Polytechnic Institute 1963. Editor, Proceedings of the Institute of Radio Engineers 1954–5.Bibliography23 October 1956, US patent no. 2,768,328 (his development of the travelling-wave tube, filed on 5 November 1946).1947, with L.M.Field, "Travelling wave tubes", Proceedings of the Institute of RadioEngineers 35:108 (describes the pioneering improvements to the travelling-wave tube). 1947, "Theory of the beam-type travelling wave tube", Proceedings of the Institution ofRadio Engineers 35:111. 1950, Travelling Wave Tubes.1956, Electronic Waves and Messages. 1962, Symbols, Signals and Noise.1981, An Introduction to Information Theory: Symbols, Signals and Noise: Dover Publications.1990, with M.A.Knoll, Signals: Revolution in Electronic Communication: W.H.Freeman.KF -
14 Ives, Herbert Eugene
[br]b. 1882 USAd. 1953[br]American physicist find television pioneer.[br]Ives gained his PhD in physics from Johns Hopkins University, Baltimore, Maryland, and subsequently served in the US Signal Corps, eventually gaining experience in aerial photography. He then joined the Western Electric Engineering Department (later Bell Telephone Laboratories), c.1920 becoming leader of a group concerned with television-image transmission over telephone lines. In 1927, using a Nipkow disc, he demonstrated 50-line, 18 frames/sec pictures that could be displayed as either 2 in.×2 1/2 in. (5.1 cm×6.4 cm) images suitable for a "wirephone", or 2 ft ×2 1/2 ft (61 cm×76 cm) images for television viewing. Two years later, using a single-spiral disc and three separately modulated light sources, he was able to produce full-colour images.[br]Bibliography1915, "The transformation of colour mixture equations", Journal of the Franklin Institute 180:673.1923, "do—Pt II", Journal of the Franklin Institute 195–23.1925, "Telephone picture transmission", Transactions of the Society of Motion Picture and Television Engineers 23:82.1929, "Television in colour", Bell Laboratories Record 7:439.1930, with A.L.Johnsrul, "Television in colour by a beam-scanning method", Journal of the Optical Society of America 20:11.Further ReadingJ.H.Udelson, 1982, The Great Television Race: History of the Television Industry 1925– 41: University of Alabama Press.KF -
15 Shannon, Claude Elwood
[br]b. 30 April 1916 Gaylord, Michigan, USA[br]American mathematician, creator of information theory.[br]As a child, Shannon tinkered with radio kits and enjoyed solving puzzles, particularly crypto-graphic ones. He graduated from the University of Michigan in 1936 with a Bachelor of Science in mathematics and electrical engineering, and earned his Master's degree from the Massachusetts Institute of Technology (MIT) in 1937. His thesis on applying Boolean algebra to switching circuits has since been acclaimed as possibly the most significant this century. Shannon earned his PhD in mathematics from MIT in 1940 with a dissertation on the mathematics of genetic transmission.Shannon spent a year at the Institute for Advanced Study in Princeton, then in 1941 joined Bell Telephone Laboratories, where he began studying the relative efficiency of alternative transmission systems. Work on digital encryption systems during the Second World War led him to think that just as ciphers hide information from the enemy, "encoding" information could also protect it from noise. About 1948, he decided that the amount of information was best expressed quantitatively in a two-value number system, using only the digits 0 and 1. John Tukey, a Princeton colleague, named these units "binary digits" (or, for short, "bits"). Almost all digital computers and communications systems use such on-off, or two-state logic as their basis of operation.Also in the 1940s, building on the work of H. Nyquist and R.V.L. Hartley, Shannon proved that there was an upper limit to the amount of information that could be transmitted through a communications channel in a unit of time, which could be approached but never reached because real transmissions are subject to interference (noise). This was the beginning of information theory, which has been used by others in attempts to quantify many sciences and technologies, as well as subjects in the humanities, but with mixed results. Before 1970, when integrated circuits were developed, Shannon's theory was not the preferred circuit-and-transmission design tool it has since become.Shannon was also a pioneer in the field of artificial intelligence, claiming that computing machines could be used to manipulate symbols as well as do calculations. His 1953 paper on computers and automata proposed that digital computers were capable of tasks then thought exclusively the province of living organisms. In 1956 he left Bell Laboratories to join the MIT faculty as Professor of Communications Science.On the lighter side, Shannon has built many devices that play games, and in particular has made a scientific study of juggling.[br]Principal Honours and DistinctionsNational Medal of Science. Institute of Electrical and Electronics Engineers Medal of Honor, Kyoto Prize.BibliographyHis seminal paper (on what has subsequently become known as information theory) was entitled "The mathematical theory of communications", first published in Bell System Technical Journal in 1948; it is also available in a monograph (written with Warren Weaver) published by the University of Illinois Press in 1949, and in Key Papers in the Development of Information Theory, ed. David Slepian, IEEE Press, 1974, 1988. For readers who want all of Shannon's works, see N.J.A.Sloane and A.D.Wyner, 1992, TheCollected Papers of Claude E.Shannon.HO -
16 Black, Harold Stephen
[br]b. 14 April 1898 Leominster, Massachusetts, USAd. 11 December 1983 Summitt, New Jersey, USA[br]American electrical engineer who discovered that the application of negative feedback to amplifiers improved their stability and reduced distortion.[br]Black graduated from Worcester Polytechnic Institute, Massachusetts, in 1921 and joined the Western Electric Company laboratories (later the Bell Telephone Laboratories) in New York City. There he worked on a variety of electronic-communication problems. His major contribution was the discovery in 1927 that the application of negative feedback to an amplifier, whereby a fraction of the output signal is fed back to the input in the opposite phase, not only increases the stability of the amplifier but also has the effect of reducing the magnitude of any distortion introduced by it. This discovery has found wide application in the design of audio hi-fi amplifiers and various control systems, and has also given valuable insight into the way in which many animal control functions operate.During the Second World War he developed a form of pulse code modulation (PCM) to provide a practicable, secure telephony system for the US Army Signal Corps. From 1963–6, after his retirement from the Bell Labs, he was Principal Research Scientist with General Precision Inc., Little Falls, New Jersey, following which he became an independent consultant in communications. At the time of his death he held over 300 patents.[br]Principal Honours and DistinctionsInstitute of Electronic and Radio Engineers Lamme Medal 1957.Bibliography1934, "Stabilised feedback amplifiers", Electrical Engineering 53:114 (describes the principles of negative feedback).21 December 1937, US patent no. 2,106,671 (for his negative feedback discovery.1947, with J.O.Edson, "Pulse code modulation", Transactions of the American Institute of Electrical Engineers 66:895.1946, "A multichannel microwave radio relay system", Transactions of the American Institute of Electrical Engineers 65:798.1953, Modulation Theory, New York: D.van Nostrand.1988, Laboratory Management: Principles \& Practice, New York: Van Nostrand Rheinhold.Further ReadingFor early biographical details see "Harold S. Black, 1957 Lamme Medalist", Electrical Engineering (1958) 77:720; "H.S.Black", Institute of Electrical and Electronics Engineers Spectrum (1977) 54.KF -
17 Townes, Charles Hard
(р. 1915) Таунс, Чарлз ХардФизик. Работал в лабораториях компании "Белл телефон" [Bell Telephone Laboratories, Bell Telephone Co.] (1939-47), преподавал в Колумбийском университете [ Columbia University] (1948-61), в Массачусетском технологическом институте [ Massachusetts Institute of Technology] (1961-66) и в Калифорнийском университете в Беркли [ California, University of] (1967-86). Лауреат Нобелевской премии 1964 по физике за работы в области квантовой электроники, приведшие к созданию генераторов и усилителей, основанных на принципе мазера - лазера (совместно с А. М. Прохоровым и Н. Г. Басовым)English-Russian dictionary of regional studies > Townes, Charles Hard
-
18 Jansky, Karl Guthe
[br]b. 22 October 1905 Norman, Oklahoma, USAd. 14 February 1950 Red Bank, New Jersey, USA[br]American radio engineer who discovered stellar radio emission.[br]Following graduation from the University of Wisconsin in 1928 and a year of postgraduate study, Jansky joined Bell Telephone Laboratories in New Jersey with the task of establishing the source of interference to telephone communications by radio. To this end he constructed a linear-directional short-wave antenna and eventually, in 1931, he concluded that the interference actually came from the stars, the major source being the constellation Sagittarius in the direction of the centre of the Milky Way. Although he continued to study the propagation of short radio waves and the nature of observed echoes, it was left to others to develop the science of radioastronomy and to use the creation of echoes for radiolocation. Although he received no scientific award for his discovery, Jansky's name is primarily honoured by its use as the unit of stellar radio-emission strength.[br]Bibliography1935, "Directional studies of atmospherics at high frequencies", Proceedings of the Institute of Radio Engineers 23:1,158.1935, "A note on the sources of stellar interference", Proceedings of the Institute of RadioEngineers.1937, "Minimum noise levels obtained on short-wave radio receiving systems", Proceedings of the Institute of Radio Engineers 25:1,517.1941, "Measurements of the delay and direction of arrival of echoes from nearby short-wave transmitters", Proceedings of the Institute of Radio Engineers 29:322.Further ReadingP.C.Mahon, 1975, BellLabs, Mission Communication. The Story of the Bell Labs.W.I.Sullivan (ed.), 1984, The Early Years of Radio-Astronomy: Reflections 50 Years after Jansky's Discovery, Cambridge: Cambridge University Press.See also: Appleton, Sir Edward VictorKF -
19 Bardeen, John
[br]b. 23 May 1908 Madison, Wisconsin, USAd. 30 January 1991 Boston, Massachusetts, USA[br]American physicist, the first to win the Nobel Prize for Physics twice.[br]Born the son of a professor of anatomy, he studied electrical engineering at the University of Wisconsin. He then worked for three years as a geophysicist at the Gulf Research Laboratories before taking a PhD in mathematical physics at Princeton, where he was a graduate student. For some time he held appointments at the University of Minnesota and at Harvard, and during the Second World War he joined the US Naval Ordnance Laboratory. In 1945 he joined the Bell Telephone Laboratories to head a new department to work on solid-state devices. While there, he and W.H. Brattain in 1948 published a paper that introduced the transistor. For this he, Brattain and Shockley won the Nobel Prize for Physics in 1956. In 1951 he moved to the University of Illinois as Professor of Physics and Electrical Engineering. There he worked on superconductivity, a phenomenon described in 1911 by Kamerling-Onnes. Bardeen worked with L.N. Cooper and J.A.Schrieffer, and in 1972 they were awarded the Nobel Prize for Physics for the "BCS Theory", which suggested that, under certain circumstances at very low temperatures, electrons can form bound pairs.[br]Principal Honours and DistinctionsNobel Prize for Physics (jointly with Brattain and Shockley) 1956, (jointly with Cooper and Schrieffer) 1972.Further ReadingIsaacs and E.Martin (eds), 1985, Longmans Dictionary of 20th Century Biography.IMcN -
20 De Forest, Lee
SUBJECT AREA: Broadcasting, Electronics and information technology, Photography, film and optics, Recording, Telecommunications[br]b. 26 August 1873 Council Bluffs, Iowa, USAd. 30 June 1961 Hollywood, California, USA[br]American electrical engineer and inventor principally known for his invention of the Audion, or triode, vacuum tube; also a pioneer of sound in the cinema.[br]De Forest was born into the family of a Congregational minister that moved to Alabama in 1879 when the father became President of a college for African-Americans; this was a position that led to the family's social ostracism by the white community. By the time he was 13 years old, De Forest was already a keen mechanical inventor, and in 1893, rejecting his father's plan for him to become a clergyman, he entered the Sheffield Scientific School of Yale University. Following his first degree, he went on to study the propagation of electromagnetic waves, gaining a PhD in physics in 1899 for his thesis on the "Reflection of Hertzian Waves from the Ends of Parallel Wires", probably the first US thesis in the field of radio.He then joined the Western Electric Company in Chicago where he helped develop the infant technology of wireless, working his way up from a modest post in the production area to a position in the experimental laboratory. There, working alone after normal working hours, he developed a detector of electromagnetic waves based on an electrolytic device similar to that already invented by Fleming in England. Recognizing his talents, a number of financial backers enabled him to set up his own business in 1902 under the name of De Forest Wireless Telegraphy Company; he was soon demonstrating wireless telegraphy to interested parties and entering into competition with the American Marconi Company.Despite the failure of this company because of fraud by his partners, he continued his experiments; in 1907, by adding a third electrode, a wire mesh, between the anode and cathode of the thermionic diode invented by Fleming in 1904, he was able to produce the amplifying device now known as the triode valve and achieve a sensitivity of radio-signal reception much greater than possible with the passive carborundum and electrolytic detectors hitherto available. Patented under the name Audion, this new vacuum device was soon successfully used for experimental broadcasts of music and speech in New York and Paris. The invention of the Audion has been described as the beginning of the electronic era. Although much development work was required before its full potential was realized, the Audion opened the way to progress in all areas of sound transmission, recording and reproduction. The patent was challenged by Fleming and it was not until 1943 that De Forest's claim was finally recognized.Overcoming the near failure of his new company, the De Forest Radio Telephone Company, as well as unsuccessful charges of fraudulent promotion of the Audion, he continued to exploit the potential of his invention. By 1912 he had used transformer-coupling of several Audion stages to achieve high gain at radio frequencies, making long-distance communication a practical proposition, and had applied positive feedback from the Audion output anode to its input grid to realize a stable transmitter oscillator and modulator. These successes led to prolonged patent litigation with Edwin Armstrong and others, and he eventually sold the manufacturing rights, in retrospect often for a pittance.During the early 1920s De Forest began a fruitful association with T.W.Case, who for around ten years had been working to perfect a moving-picture sound system. De Forest claimed to have had an interest in sound films as early as 1900, and Case now began to supply him with photoelectric cells and primitive sound cameras. He eventually devised a variable-density sound-on-film system utilizing a glow-discharge modulator, the Photion. By 1926 De Forest's Phonofilm had been successfully demonstrated in over fifty theatres and this system became the basis of Movietone. Though his ideas were on the right lines, the technology was insufficiently developed and it was left to others to produce a system acceptable to the film industry. However, De Forest had played a key role in transforming the nature of the film industry; within a space of five years the production of silent films had all but ceased.In the following decade De Forest applied the Audion to the development of medical diathermy. Finally, after spending most of his working life as an independent inventor and entrepreneur, he worked for a time during the Second World War at the Bell Telephone Laboratories on military applications of electronics.[br]Principal Honours and DistinctionsInstitute of Electronic and Radio Engineers Medal of Honour 1922. President, Institute of Electronic and Radio Engineers 1930. Institute of Electrical and Electronics Engineers Edison Medal 1946.Bibliography1904, "Electrolytic detectors", Electrician 54:94 (describes the electrolytic detector). 1907, US patent no. 841,387 (the Audion).1950, Father of Radio, Chicago: WIlcox \& Follett (autobiography).De Forest gave his own account of the development of his sound-on-film system in a series of articles: 1923. "The Phonofilm", Transactions of the Society of Motion Picture Engineers 16 (May): 61–75; 1924. "Phonofilm progress", Transactions of the Society of Motion Picture Engineers 20:17–19; 1927, "Recent developments in the Phonofilm", Transactions of the Society of Motion Picture Engineers 27:64–76; 1941, "Pioneering in talking pictures", Journal of the Society of Motion Picture Engineers 36 (January): 41–9.Further ReadingG.Carneal, 1930, A Conqueror of Space (biography).I.Levine, 1964, Electronics Pioneer, Lee De Forest (biography).E.I.Sponable, 1947, "Historical development of sound films", Journal of the Society of Motion Picture Engineers 48 (April): 275–303 (an authoritative account of De Forest's sound-film work, by Case's assistant).W.R.McLaurin, 1949, Invention and Innovation in the Radio Industry.C.F.Booth, 1955, "Fleming and De Forest. An appreciation", in Thermionic Valves 1904– 1954, IEE.V.J.Phillips, 1980, Early Radio Detectors, London: Peter Peregrinus.KF / JW
Страницы
- 1
- 2
См. также в других словарях:
Bell Telephone Laboratories — Bell Labs in Murray Hill, New Jersey Bell Laboratories bzw. Bell Labs (Ältere Bezeichnung BTL, Bell Telephone Laboratories Inc.) ist Teil der Forschungs und Entwicklungsabteilung von Alcatel Lucent. Der Hauptsitz der Bell Labs ist in Murray Hill … Deutsch Wikipedia
Bell Telephone Laboratories — … Википедия
Bell Telephone Building — or variations including Southwestern Bell Telephone Building or Old Bell Telephone Building, may refer to: in the United States (by state, then city) Old Bell Telephone Building (Osceola, Arkansas), listed on the NRHP in Mississippi County,… … Wikipedia
Bell Labs — Bell Laboratories (also known as Bell Labs and formerly known as AT T Bell Laboratories and Bell Telephone Laboratories) is the research organization of Alcatel Lucent and previously the American Telephone Telegraph Company (AT T). Bell… … Wikipedia
Bell-Laboratorien — Bell Labs in Murray Hill, New Jersey Bell Laboratories bzw. Bell Labs (Ältere Bezeichnung BTL, Bell Telephone Laboratories Inc.) ist Teil der Forschungs und Entwicklungsabteilung von Alcatel Lucent. Der Hauptsitz der Bell Labs ist in Murray Hill … Deutsch Wikipedia
Bell Labs — in Murray Hill, New Jersey Bell Laboratories bzw. Bell Labs (Ältere Bezeichnung BTL, Bell Telephone Laboratories Inc.) ist Teil der Forschungs und Entwicklungsabteilung von Alcatel Lucent. Der Hauptsitz der Bell Labs ist in Murray Hill, New… … Deutsch Wikipedia
Bell Laboratories — U.S. research and development company (founded 1925) that develops telecommunications equipment and carries out defense related research. Formerly part of AT&T, it now belongs to Lucent Technologies, Inc., which spun off from AT&T in 1996. Bell… … Universalium
Bell Laboratories — Alcatel Lucent Bell Labs in Murray Hill, New Jersey Die Bell Laboratories bzw. Bell Labs (ältere Bezeichnungen: BTL, Bell Telephone Laboratories Inc.) sind Teil der Forschungs und Entwicklungsabteilung von Alcatel Lucent. Der Hauptsitz der Bell… … Deutsch Wikipedia
Bell Laboratories Building (Manhattan) — Infobox nrhp name = Bell Telephone Laboratories nrhp type = nhl caption = location = 463 West Street, Manhattan, New York City, New York nearest city = lat degrees = 40 | lat minutes = 44 | lat seconds = 11.8 | lat direction = N long degrees = 74 … Wikipedia
Bell Labs — Лаборатории Белла в Мюррей Хилл (Нью Джерси, США) Координаты … Википедия
Bell Laboratories — Laboratoires Bell Pour les articles homonymes, voir Bell. Bell Labs … Wikipédia en Français
