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Radiotechnique
Radiotechnique (RT) was a French electronics company that made radio transmitting and receiving vacuum tubes, and later more advanced components such as integrated circuits and solar panels. At first it was a subsidiary of the French Compagnie générale de la télégraphie sans fil (CSF). Later it became a subsidiary of Philips of the Netherlands. The company expanded after World War II, moving into television and electronics, including photovoltaics and printed circuits, and in 1979 had about 15,000 employees. Later it lost market share, went through various restructurings, was sold in 1998 and went bankrupt in 2002. CSF subsidiary (1919–31) The Compagnie générale de la télégraphie sans fil (CSF) was formed in 1919 as a holding company for the Société française radio-électrique and other subsidiaries in fields related to radio-electricity. Radiotechnique was initially based in Lyon in 1919. The Radiotechnique subsidiary of the CSF was formed in 1919 to research and dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compagnie Générale De La Télégraphie Sans Fil
The Compagnie générale de la télégraphie sans fil (CSF: General Wireless Telegraphy Company) was a French company founded in 1918 during a reorganization and expansion of the Société française radio-électrique (SFR), which became a subsidiary. The company developed technology for radio-telegraphy, radio program transmission, radar, television and other applications. It provided broadcasting and telegraphy services, and sold its equipment throughout the French colonial empire and in many other parts of the world. In 1968 CSF merged with the Thomson-Brandt to form Thomson-CSF. Background From the mid-19th century the world was connected with an increasingly dense network of telegraph wires and submarine cables. In 1887 Heinrich Hertz of Germany conclusively proved the existence of electromagnetic waves. Alexander Stepanovich Popov of Russia developed antennas to transmit and receive radio waves. Scientists such as Édouard Branly and Nikola Tesla also contributed to developm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
City
A city is a human settlement of notable size.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge. It can be defined as a permanent and densely settled place with administratively defined boundaries whose members work primarily on non-agricultural tasks. Cities generally have extensive systems for housing, transportation, sanitation, utilities, land use, production of goods, and communication. Their density facilitates interaction between people, government organisations and businesses, sometimes benefiting different parties in the process, such as improving efficiency of goods and service distribution. Historically, city-dwellers have been a small proportion of humanity overall, but following two centuries of unprecedented and rapid urbanization, more than half of the world population now lives in cities, which has had profound consequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dreux
Dreux () is a commune in the Eure-et-Loir department in northern France. Geography Dreux lies on the small river Blaise, a tributary of the Eure, about 35 km north of Chartres. Dreux station has rail connections to Argentan, Paris and Granville. The Route nationale 12 (Paris–Rennes) passes north of the town. History Dreux was known in ancient times as Durocassium, the capital of the Durocasses Celtic tribe. Despite the legend, its name was not related with Druids. The Romans established here a fortified camp known as Castrum Drocas. In the Middle Ages, Dreux was the centre of the County of Dreux. The first count of Dreux was Robert, the son of King Louis the Fat. The first large battle of the French Wars of Religion occurred at Dreux, on 19 December 1562, resulting in a hard-fought victory for the Catholic forces of the duc de Montmorency. In October 1983, the Front National won 55% of the vote in the second round of elections for the city council of Dreux, in on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thoriated Filament
In vacuum tubes and gas-filled tubes, a hot cathode or thermionic cathode is a cathode electrode which is heated to make it emit electrons due to thermionic emission. This is in contrast to a cold cathode, which does not have a heating element. The heating element is usually an electrical filament heated by a separate electric current passing through it. Hot cathodes typically achieve much higher power density than cold cathodes, emitting significantly more electrons from the same surface area. Cold cathodes rely on field electron emission or secondary electron emission from positive ion bombardment, and do not require heating. There are two types of hot cathode. In a ''directly heated cathode'', the filament is the cathode and emits the electrons. In an ''indirectly heated cathode'', the filament or ''heater'' heats a separate metal cathode electrode which emits the electrons. From the 1920s to the 1960s, a wide variety of electronic devices used hot-cathode vacuum tubes. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally. It is one of the top 10 semiconductor companies worldwide based on sales volume. The company's focus is on developing analog chips and embedded processors, which account for more than 80% of its revenue. TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers, and multi-core processors. The company holds 45,000 patents worldwide as of 2016. Texas Instruments emerged in 1951 after a reorganization of Geophysical Service Incorporated, a company founded in 1930 that manufactured equipment for use in the seismic industry, as well as defense electronics. TI produced the world's first commercial silicon transistor in 1954, and the same year designed and manufa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groupe Bull
Bull SAS (also known as Groupe Bull, Bull Information Systems, or simply Bull) is a French computer company headquartered in Les Clayes-sous-Bois, in the western suburbs of Paris. The company has also been known at various times as Bull General Electric, Honeywell Bull, CII Honeywell Bull, and Bull HN. Bull was founded in 1931, as H.W. Egli - Bull, to capitalize on the punched card technology patents of Norwegian engineer Fredrik Rosing Bull (1882–1925). After a reorganization in 1933, with new owners coming in, the name was changed to Compagnie des Machines Bull (CMB). Bull has a worldwide presence in more than 100 countries and is particularly active in the defense, finance, health care, manufacturing, public, and telecommunication sectors. History Origins On 31 July 1919, a Norwegian engineer named Fredrik Rosing Bull filed a patent for a "combined sorter-recorder-tabulator of punch cards" machine that he had developed with financing from the Norwegian insuran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sylvania Electric Products
Sylvania Electric Products Inc. was an American manufacturer of diverse electrical equipment, including at various times radio transceivers, vacuum tubes, semiconductors, and mainframe computers such as MOBIDIC. They were one of the companies involved in the development of the COBOL programming language. History The ''Hygrade Sylvania Corporation'' was formed when '' NILCO'', ''Sylvania'' and '' Hygrade Lamp Company'' merged into one company in 1931. In 1939, Hygrade Sylvania started preliminary research on fluorescent technology, and later that year, demonstrated the first linear, or tubular, fluorescent lamp. It was featured at the 1939 New York World's Fair. Sylvania was also a manufacturer of both vacuum tubes and transistors. In 1942, the company changed its name to Sylvania Electric Products Inc. During World War II, Sylvania was chosen from among several competing companies to manufacture the miniature vacuum tubes used in proximity fuze shells due to its quality st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photovoltaics
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially used for electricity generation and as photosensors. A photovoltaic system employs solar modules, each comprising a number of solar cells, which generate electrical power. PV installations may be ground-mounted, rooftop-mounted, wall-mounted or floating. The mount may be fixed or use a solar tracker to follow the sun across the sky. Photovoltaic technology helps to mitigate climate change because it emits much less carbon dioxide than fossil fuels. Solar PV has specific advantages as an energy source: once installed, its operation generates no pollution and no greenhouse gas emissions, it shows scalability in respect of power needs and silicon has large availability in the Earth's crust, although other materials required in PV s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photomultiplier
A photomultiplier is a device that converts incident photons into an electrical signal. Kinds of photomultiplier include: * Photomultiplier tube, a vacuum tube converting incident photons into an electric signal. Photomultiplier tubes (PMTs for short) are members of the class of vacuum tubes, and more specifically vacuum phototubes, which are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. ** Magnetic photomultiplier, developed by the Soviets in the 1930s. ** Electrostatic photomultiplier, a kind of photomultiplier tube demonstrated by Jan Rajchman of RCA Laboratories in Princeton, NJ in the late 1930s which became the standard for all future commercial photomultipliers. The first mass-produced photomultiplier, the Type 931, was of this design and is still commercially produced today. * Silicon photomultiplier, a solid-state device converting incident photons into an electric signal. Silicon photomu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomson-CSF
Thomson-CSF was a French company that specialized in the development and manufacture of electronics with a heavy focus upon the aerospace and defence (military), defence sectors of the market. Thomson-CSF was formed in 1968 following the merger of Hotchkiss-Brandt, Thomson-Houston-Hotchkiss-Brandt with the Compagnie Générale de Télégraphie Sans Fil (''General Wireless Telegraphy Company'', commonly abbreviated as ''CSF''), these two companies being the source of the name ''Thomson-CSF''. It operated as an electronics specialist on products such as broadcasting equipment, Acoustical engineering#Electroacoustics, electroacoustics, shortwave radio sets, radar systems and television. During the 1970s, the company diversified manufacturing Telephone exchange, backend telephony equipment, semiconductors, and medical imaging apparatus. It also entered into large deals outside of the domestic market, acquiring considerable business in the Middle East. During the late 1980s, Thomso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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