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Cold-cathode
A cold cathode is a cathode that is not electrically heated by a filament.A negatively charged electrode emits electrons or is the positively charged terminal. For more, see field emission. A cathode may be considered "cold" if it emits more electrons than can be supplied by thermionic emission alone. It is used in gas-discharge lamps, such as neon lamps, discharge tubes, and some types of vacuum tube. The other type of cathode is a hot cathode, which is heated by electric current passing through a filament. A cold cathode does not necessarily operate at a low temperature: it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas. Cold-cathode devices A cold-cathode vacuum tube does not rely on external heating of an electrode to provide thermionic emission of electrons. Early cold-cathode devices included the Geissler tube and Plucker tube, and early cathode-ray tubes. Study of the phenomena in these device ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold-cathode Fluorescent Lamp
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than an incandescent lamp. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. For comparison, the luminous efficacy of an incandescent bulb may only be 16 lumens per watt. Fluorescent lamp fixtures are more costly than incandescent lamps because, among other things, they require a ballast to regulate current through the lamp, but the initial cost is offset by a much lower running cost. Compact fluorescent lamps are now available in the same popular sizes as incandesc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode-ray Tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms (oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term ''cathode ray'' was used to describe electron beams when they were first discovered, before it was understood that what was emitted from the cathode was a beam of electrons. In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and blue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discharge Tube
A gas-filled tube, also commonly known as a discharge tube or formerly as a Plücker tube, is an arrangement of electrodes in a gas within an insulating, temperature-resistant envelope. Gas-filled tubes exploit phenomena related to electric discharge in gases, and operate by ionizing the gas with an applied voltage sufficient to cause electrical conduction by the underlying phenomena of the Townsend discharge. A gas-discharge lamp is an electric light using a gas-filled tube; these include fluorescent lamps, metal-halide lamps, sodium-vapor lamps, and neon lights. Specialized gas-filled tubes such as krytrons, thyratrons, and ignitrons are used as switching devices in electric devices. The voltage required to initiate and sustain discharge is dependent on the pressure and composition of the fill gas and geometry of the tube. Although the envelope is typically glass, power tubes often use ceramics, and military tubes often use glass-lined metal. Both hot cathode and cold cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krytron
The krytron is a cold-cathode gas-filled tube intended for use as a very high-speed switch, somewhat similar to the thyratron. It consists of a sealed glass tube with four electrodes. A small triggering pulse on the control grid, grid electrode switches the tube on, allowing a large current to flow between the cathode and anode electrodes. The vacuum version is called a vacuum krytron, or sprytron. The krytron was one of the earliest developments of the EG&G Corporation. Description Unlike most other gas switching tubes, the krytron conducts by means of an electric arc, arc discharge, to handle very high voltages and currents (reaching several kilovolts and several kiloamperes), rather than the low-current electric glow discharge, glow discharge used in other thyratrons. The krytron is a development of the Spark gap, triggered spark gaps and thyratrons originally developed for radar transmitters during World War II. The gas used in krytrons is hydrogen; [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nixie Tube
A Nixie tube ( ), or cold cathode display, is an electronic device used for displaying numerals or other information using glow discharge. The glass tube contains a wire-mesh anode and multiple cathodes, shaped like numerals or other symbols. Applying power to one cathode surrounds it with an orange glow discharge. The tube is filled with a gas at low pressure, usually mostly neon and often a little mercury or argon, in a Penning mixture. Although it resembles a vacuum tube in appearance, its operation does not depend on thermionic emission of electrons from a heated cathode. It is hence a cold-cathode tube (a form of gas-filled tube), and is a variant of the neon lamp. Such tubes rarely exceed even under the most severe of operating conditions in a room at ambient temperature. Vacuum fluorescent displays from the same era use completely different technology—they have a heated cathode together with a control grid and shaped phosphor anodes; Nixies have no heater or control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, 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. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such as signal amplifier, amplification and current rectifier, rectification. Non-thermionic types such as a vacuum phototube, however, achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light intensities. In both types, the electrons are accelerated from the cathode to the anode by the electric field in the tube. The simplest vacuum tube, the diode (i.e. Fleming valve), invented in 1904 by John Ambrose Fleming, contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through the device—fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dekatron
In electronics, a Dekatron (or Decatron, or generically three-phase gas counting tube or glow-transfer counting tube or cold cathode tube) is a gas-filled decade counting tube. Dekatrons were used in computers, calculators, and other counting-related products during the 1950s and 1960s. "Dekatron," now a generic trademark, was the brand name used by Ericsson Telephones Limited (ETL), of Beeston, Nottingham (not to be confused with the Swedish TelefonAB Ericsson of Stockholm). The device was invented by John Reginald Acton, with the patent assigned to Ericsson. US2651004A The dekatron was useful for computing, calculating, and frequency-dividing purposes because one complete revolution of the neon dot in a dekatron means 10 pulses on the guide electrode(s), and a signal can be derived from one of the ten cathodes in a dekat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Discharge Lamp
Gas-discharge lamps are a family of artificial light sources that generate light by sending an electric discharge through an ionized gas, a plasma. Typically, such lamps use a noble gas (argon, neon, krypton, and xenon) or a mixture of these gases. Some include additional substances, like mercury, sodium, and metal halides, which are vaporized during startup to become part of the gas mixture. Single ended self-starting lamps are insulated with a mica disc and contained in a borosilicate glass gas discharge tube (arc tube) and a metal cap. They include the sodium-vapor lamp that is the gas-discharge lamp in street lighting. In operation, some of the electrons are forced to leave the atoms of the gas near the anode by the electric field applied between the two electrodes, leaving these atoms positively ionized. The free electrons thus released flow onto the anode, while the cations thus formed are accelerated by the electric field and flow towards the cathode. Typically, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode
A cathode is the electrode from which a conventional current leaves a polarized electrical device. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. A conventional current describes the direction in which positive charges move. Electrons have a negative electrical charge, so the movement of electrons is opposite to that of the conventional current flow. Consequently, the mnemonic ''cathode current departs'' also means that electrons flow ''into'' the device's cathode from the external circuit. For example, the end of a household battery marked with a + (plus) is the cathode. The electrode through which conventional current flows the other way, into the device, is termed an anode. Charge flow Conventional current flows from cathode to anode outside of the cell or device (with electrons moving in the opposite direction), regardless of the cell or device type and operating mode. Cathode polarity with respect to the anode can be positive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by multinational company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. Researchers working at Bell Laboratories are credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Nine Nobel Prizes have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. In the late 19th century, the laboratory began as the Western Electric Engineering Department, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Circuit
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny MOSFETs (metal–oxide–semiconductor field-effect transistors) integrate into a small chip. This results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The IC's mass production capability, reliability, and building-block approach to integrated circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones and other home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs such as modern computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Tube
Flash, flashes, or FLASH may refer to: Arts, entertainment, and media Fictional aliases * Flash (DC Comics character), several DC Comics superheroes with super speed: ** Flash (Barry Allen) ** Flash (Jay Garrick) ** Wally West, the first Kid Flash and third adult Flash ** Bart Allen, the second Kid Flash who also became the adult hero for a time * Flash (G.I. Joe), a character in the G.I. Joe universe * Flash, a robot in the video game Brave series, ''Brave Saga 2'' * Flash, a character in the comedy film ''Daddy Day Care'' (2003) * Flash, a character in the TV science fiction drama ''Real Humans'' * Flash, a character in the 1989 American action comedy movie ''Speed Zone#Cast, Speed Zone'' * Flash, a character in the TV sitcom ''List of Step by Step episodes, Step by Step'' * Flash, a character in the film ''Zootopia'' (2016) * Flash Gordon, the titular hero of science fiction comic strip * My Little Pony: Equestria Girls#Flash Sentry, Flash Sentry, in ''My Little Pony: Friends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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