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Screen Grid
A tetrode is a vacuum tube (called ''valve'' in British English) having four active electrodes. The four electrodes in order from the centre are: a thermionic cathode, first and second grids, and a plate (called ''anode'' in British English). There are several varieties of tetrodes, the most common being the screen-grid tube and the beam tetrode. In screen-grid tubes and beam tetrodes, the first grid is the control grid and the second grid is the screen grid. In other tetrodes one of the grids is a control grid, while the other may have a variety of functions. The tetrode was developed in the 1920s by adding an additional grid to the first amplifying vacuum tube, the triode, to correct limitations of the triode. During the period 1913 to 1927, three distinct types of tetrode valves appeared. All had a normal control grid whose function was to act as a primary control for current passing through the tube, but they differed according to the intended function of the other grid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It takes the form of an evacuated tubular envelope of glass or sometimes metal containing electrodes connected to external connection pins. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental Electronics, electronic functions such as signal amplifier, amplification and current Rectifier, rectification. Non-thermionic types such as vacuum phototubes achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light and measurement of its intensity. In both types the electrons are accelerated from the cathode to the anode by the electric field in the tube. The first, and simplest, vacuum tube, the diode or Flem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thorpe K4 Bi-Grid Valve
Thorpe is a variant of the Middle English word '' thorp'', meaning hamlet or small village. Thorpe may refer to: People * Thorpe (surname), including a list of people with the name Places England * Thorpe, Cumbria * Thorpe, Derbyshire * Thorpe, East Lindsey, Lincolnshire * Thorpe, East Riding of Yorkshire * Thorpe, North Yorkshire * Thorpe, Nottinghamshire * Thorpe, Surrey * Thorpe Arnold, Leicestershire * Thorpe Bay, a suburb in Essex * Thorpe by Trusthorpe, Lincolnshire * Thorpe by Water, Rutland, East Midlands * Thorpe Constantine, Staffordshire * Thorpe Culvert, a hamlet in Lincolnshire * Thorpe Hamlet, Norwich, Norfolk * Thorpe Hesley, South Yorkshire *Thorpe in Balne, South Yorkshire * Thorpe in the Fallows, Lincolnshire * Thorpe Latimer, Lincolnshire *Thorpe-le-Soken, Essex * Thorpe le Street, East Riding of Yorkshire * Thorpe Mandeville, Northamptonshire * Thorpe Market, Norfolk * Thorpe-next-Haddiscoe, Norfolk * Thorpe on the Hill, Lincolnshire * Thorpe on the Hill, W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Press
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflex Receiver
A reflex radio receiver, occasionally called a reflectional receiver, is a radio receiver design in which the same amplifier is used to amplify the high-frequency radio signal (RF) and low-frequency audio signal, audio (sound) signal (AF). It was first invented in 1914 by German scientists Wilhelm Schloemilch and Otto von Bronk,US Patent no. 1087892, Wilhelm Schloemilch and Otto von Bronk Means for receiving electrical oscillations', filed March 14, 1913; granted February 17, 1914 and rediscovered and extended to multiple tubes in 1917 by Marius LatourUS Patent no. 1405523, Marius Latour Audion or lamp relay or amplifying apparatus', filed December 28, 1917; granted February 7, 1922 and William H. Priess. The radio signal from the antenna and tuned circuit passes through an amplifier, is demodulation, demodulated in a detector (radio), detector which extracts the audio signal from the radio carrier signal, carrier, and the resulting audio signal passes ''again'' through the same am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric
General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston. Over the years, the company had multiple divisions, including GE Aerospace, aerospace, GE Power, energy, GE HealthCare, healthcare, lighting, locomotives, appliances, and GE Capital, finance. In 2020, GE ranked among the Fortune 500, ''Fortune'' 500 as the 33rd largest firm in the United States by gross revenue. In 2023, the company was ranked 64th in the Forbes Global 2000, ''Forbes'' Global 2000. In 2011, GE ranked among the Fortune 20 as the 14th most profitable company, but later very severely underperformed the market (by about 75%) as its profitability collapsed. Two employees of GE—Irving Langmuir (1932) and Ivar Giaever (1973)—have been awarded the Nobel Prize. From 1986 until 2013, GE was the owner of the NBC television network through its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrometer
An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical handmade mechanical instruments to high-precision electronic devices. Modern electrometers based on vacuum tube or solid-state technology can be used to make voltage and charge measurements with very low leakage currents, down to 1 femtoampere. A simpler but related instrument, the electroscope, works on similar principles but only indicates the relative magnitudes of voltages or charges. Historical electrometers Gold-leaf electroscope The gold-leaf electroscope was one of the instruments used to indicate electric charge. It is still used for science demonstrations but has been superseded in most applications by electronic measuring instruments. The instrument consists of two thin leaves of gold foil suspended from an electrode. When the electrode is charged by induction or by contact, the leaves acquire si ... [...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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MMA International
Mixed martial arts (MMA) is a full-contact fighting sport based on striking and grappling; incorporating techniques from various combat sports from around the world. In the early 20th century, various inter-stylistic contests took place throughout Japan and the countries of East Asia. At the same time, in Brazil there was a phenomenon called vale tudo, which became known for unrestricted fights between various styles such as judo, Brazilian jiu-jitsu, catch wrestling, luta livre, Muay Thai and capoeira. An early high-profile mixed bout was Kimura vs Gracie in 1951. In mid-20th century Hong Kong, rooftop street fighting contests between different martial arts styles gave rise to Bruce Lee's hybrid martial arts style Jeet Kune Do. Another precursor to modern MMA was the 1976 Ali vs. Inoki exhibition bout, fought between boxer Muhammad Ali and wrestler Antonio Inoki in Japan, where it later inspired the foundation of Shooto in 1985, Pancrase in 1993, and the Pride Fighting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transconductance
Transconductance (for transfer conductance), also infrequently called mutual conductance, is the electrical characteristic relating the current through the output of a device to the voltage across the input of a device. Conductance is the reciprocal of resistance. Transadmittance (or transfer admittance) is the AC equivalent of transconductance. Definition Transconductance is very often denoted as a conductance, , with a subscript, , for ''mutual''. It is defined as follows: : g_\text = \frac For small signal alternating current, the definition is simpler: : g_\text = \frac The SI unit for transconductance is the siemens, with the symbol S, as in conductance. Transresistance Transresistance (for transfer resistance), also infrequently referred to as mutual resistance, is the dual of transconductance. It refers to the ratio between a change of the voltage at two output points and a related change of current through two input points, and is denotated as : : r_\text = \ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessment to form Cambridge University Press and Assessment under Queen Elizabeth II's approval in August 2021. With a global sales presence, publishing hubs, and offices in more than 40 countries, it published over 50,000 titles by authors from over 100 countries. Its publications include more than 420 academic journals, monographs, reference works, school and university textbooks, and English language teaching and learning publications. It also published Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. It also served as the King's Printer. Cambridge University Press, as part of the University of Cambridge, was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
