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Electric Discharge
In electromagnetism, an electric discharge is the release and transmission of electricity in an applied electric field through a medium such as a gas (i.e., an outgoing flow of electric current through a non-metal medium).American Geophysical Union, National Research Council (U.S.). Geophysics Study Committee (1986) ''The earth's electrical environment''. National Academy Press, Washington, DC, p. 263. Applications The properties and effects of electric discharges are useful over a wide range of magnitudes. Tiny pulses of current are used to detect ionizing radiation in a Geiger–Müller tube. A low steady current can illustrate the gas spectrum in a gas-filled tube. A neon lamp is an example of a gas-discharge lamp, useful both for illumination and as a voltage regulator. A flashtube generates a short pulse of intense light useful for photography by sending a heavy current through a gas arc discharge. Corona discharges are used in photocopiers. Electric discharges can convey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glow Discharge Current-voltage Curve English
Glow or GLOW may refer to: In science and technology In computing and telecommunications * Glow (JavaScript library), an open-source JavaScript library created by the BBC * Glow (Scottish Schools National Intranet), a telecommunications project in Scotland In physics * Incandescence, the emission of electromagnetic radiation from a hot object * Luminescence, any form of light emission ''not'' resulting from heat * List of light sources Other uses in science and technology * Glow or Bloom (shader effect), computer graphics effect * GLOW (gross lift-off weight), see maximum takeoff weight In arts and entertainment In film and television * ''The Glow'' (film), a 2002 TV film starring Portia de Rossi * ''Glow'' (2000 film), a film starring Frankie Ingrassia * ''Glow'' (2011 film), a film starring Tony Lo Bianco * ''The Glow'' (TV series), a 2000s television series starring Dean Cain * GLOW TV, a syndicated televised version of the Gorgeous Ladies of Wrestling events from 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marx Generator
A Marx generator is an electrical circuit first described by Erwin Otto Marx in 1924. Its purpose is to generate a high-voltage pulse from a low-voltage DC supply. Marx generators are used in high-energy physics experiments, as well as to simulate the effects of lightning on power-line gear and aviation equipment. A bank of 36 Marx generators is used by Sandia National Laboratories to generate X-rays in their Z Machine. Principle of operation The circuit generates a high-voltage pulse by charging a number of capacitors in parallel, then suddenly connecting them in series. See the circuit diagram on the right. At first, ''n'' capacitors (''C'') are charged in parallel to a voltage ''VC'' by a DC power supply through the resistors (''R''C). The spark gaps used as switches have the voltage ''VC'' across them, but the gaps have a breakdown voltage greater than ''VC'', so they all behave as open circuits while the capacitors charge. The last gap isolates the output of the generator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Arc
A vacuum arc can arise when the surfaces of metal electrodes in contact with a good vacuum begin to emit electrons either through heating ( thermionic emission) or in an electric field that is sufficient to cause field electron emission. Once initiated, a vacuum arc can persist, since the freed particles gain kinetic energy from the electric field, heating the metal surfaces through high-speed particle collisions. This process can create an incandescent cathode spot, which frees more particles, thereby sustaining the arc. At sufficiently high currents an incandescent anode spot may also be formed. Electric discharge in vacuum is important for certain types of vacuum tubes and for high-voltage vacuum switches. The thermionic vacuum arc (TVA) is a new type of plasma source, which generates a plasma containing ions with a directed energy. TVA discharges can be ignited in high-vacuum conditions between a heated cathode (electron gun) and an anode (tungsten crucible) containing the ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streamer Discharge
In electromagnetism, a streamer discharge, also known as filamentary discharge, is a type of transient electric discharge which forms at the surface of a conductive electrode carrying a high voltage in an Insulator (electricity), insulating medium such as air. Streamers are luminous writhing branching sparks, plasma (physics), plasma channels composed of ionization, ionized air molecules, which repeatedly strike out from the electrode into the air. Like the related corona discharges and brush discharges, a streamer discharge represents a region around a high voltage Electrical conductor, conductor where the air has suffered electrical breakdown and become conductive (ionization, ionized), so electric charge is leaking off the electrode into the air, but the opposite polarity electrode is not close enough to create an electric arc between the two electrodes. It occurs when the electric field at the surface of a conductor exceeds the dielectric strength of air, around 30 ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Discharge
In electrical engineering, partial discharge (PD) is a localized dielectric breakdown (DB) (which does not completely bridge the space between the two conductors) of a small portion of a solid or fluid electrical insulation (EI) system under high voltage (HV) stress. While a corona discharge (CD) is usually revealed by a relatively steady glow or brush discharge (BD) in air, partial discharges within solid insulation system are not visible. PD can occur in a gaseous, liquid, or solid insulating medium. It often starts within gas voids, such as voids in solid epoxy insulation or bubbles in transformer oil. Protracted partial discharge can erode solid insulation and eventually lead to breakdown of insulation. Discharge mechanism PD usually begins within voids, cracks, or inclusions within a solid dielectric, at conductor-dielectric interfaces within solid or liquid dielectrics, or in bubbles within liquid dielectrics. Since PDs are limited to only a portion of the insulati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leader (spark)
In electromagnetism, a leader is a hot, highly conductive channel of plasma that plays a critical part during dielectric breakdown within a long electric spark. Mechanism When a gas is subjected to high voltage stress, the electric field is often quite non-uniform near one, or both, of the high voltage electrodes making up a spark gap. Breakdown initially begins with the formation of corona discharges near the electrode with the highest electrical stress. If the electrical field is further increased, longer length ''cold'' discharges (called '' streamers'' or ''burst corona'') sporadically form near the stressed electrode. Streamers attract multiple electron avalanches into a single channel, propagating forward quickly via photon emission which leads to photoelectrons producing new avalanches. Streamers redistribute charge within the surrounding gas, temporarily forming regions of excess charge ( space charges) in the regions surrounding the discharges. If the electrical field i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Discharge In Gases
Electric discharge in gases occurs when electric current flows through a gaseous medium due to ionization of the gas. Depending on several factors, the discharge may radiate visible light. The properties of electric discharges in gases are studied in connection with design of lighting sources and in the design of high voltage electrical equipment. Discharge types In cold cathode tubes, the electric discharge in gas has three regions, with distinct current–voltage characteristics:Reference Data for Engineers: Radio, Electronics, Computers and Communications By Wendy Middleton, Mac E. Van Valkenburg, p. 16-42, Newnes, 2002 *I: Townsend discharge, below the breakdown voltage. At low voltages, the only current i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatic Discharge
Electrostatic discharge (ESD) is a sudden and momentary flow of electric current between two differently-charged objects when brought close together or when the dielectric between them breaks down, often creating a visible electric spark, spark associated with the static electricity between the objects. ESD can create spectacular electric sparks (lightning, with the accompanying sound of thunder, is an example of a large-scale ESD event), but also less dramatic forms, which may be neither seen nor heard, yet still be large enough to cause damage to sensitive electronic devices. Electric sparks require a field strength above approximately 4 million V/m in air, as notably occurs in lightning strikes. Other forms of ESD include corona discharge from sharp electrodes, brush discharge from blunt electrodes, etc. ESD can cause harmful effects of importance in industry, including explosions in gas, fuel vapor and coal dust, as well as failure of solid state electronics components such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Arc
An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The electric current, current through a normally Electrical conductance, nonconductive medium such as air produces a plasma (physics), plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field emission. After initiation, the arc relies on thermionic emission of electrons from the electrodes supporting the arc. An arc discharge is characterized by a lower voltage than a glow discharge. An archaic term is voltaic arc, as used in the phrase "voltaic arc lamp". Techniques for arc suppression can be used to reduce the duration or likelihood of arc formation. In the late 19th century, Arc lamp, electric arc lighting was in wide use for Street light#Arc lamps, public lighting. Some low-pressure electric arcs are used in many applications. For example, fluorescent lamp, fluorescent tubes, mercury, sodium, and met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Glow Discharge
A glow discharge is a plasma formed by the passage of electric current through a gas. It is often created by applying a voltage between two electrodes in a glass tube containing a low-pressure gas. When the voltage exceeds a value called the striking voltage, the gas ionization becomes self-sustaining, and the tube glows with a colored light. The color depends on the gas used. Glow discharges are used as a source of light in devices such as neon lights, cold cathode fluorescent lamps and plasma-screen televisions. Analyzing the light produced with spectroscopy can reveal information about the atomic interactions in the gas, so glow discharges are used in plasma physics and analytical chemistry. They are also used in the surface treatment technique called sputtering. Electrical conduction in gas Conduction in a gas requires charge carriers, which can be either electrons or ions. Charge carriers come from ionizing some of the gas molecules. In terms of current flow, glow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dielectric Barrier Discharge
Dielectric-barrier discharge (DBD) is the electrical discharge between two electrodes separated by an insulating dielectric barrier. Originally called silent (inaudible) discharge and also known as ozone production discharge or partial discharge, it was first reported by Ernst Werner von Siemens in 1857.Kogelschatz, Ulrich, Baldur Eliasson, and Walter EgliFrom ozone generators to flat television screens: history and future potential of dielectric-barrier discharges Pure Applied Chemistry, Vol. 71, No. 10, pp. 1819–1828, 1999. Retrieved on 5 August 2007. Process The process normally uses high voltage alternating current, ranging from lower RF to microwave frequencies. However, other methods were developed to extend the frequency range all the way down to the DC. One method was to use a high resistivity layer to cover one of the electrodes. This is known as the resistive barrier discharge.M. Laroussi, I. Alexeff, J. P. Richardson, and F. F. Dyer " The Resistive Barrier D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brush Discharge
A brush discharge is an electrical disruptive discharge similar to a corona discharge that takes place at an electrode with a high voltage applied to it, embedded in a nonconducting fluid, usually air. It is characterized by numerous luminous writhing sparks, plasma streamers composed of ionized air molecules, which repeatedly strike out from the electrode into the air, often with a crackling sound. The streamers spread out in a fan shape, giving it the appearance of a "brush". Corona and brush discharges are sometimes called ''one-electrode discharges'' because they occur in the vicinity of a single electrode, and don't extend as far as the electrode carrying opposite polarity voltage in the circuit, as an electric arc (a ''two-electrode discharge'') does. *''Corona discharge'' — occurs at sharp points and edges (radius < 1 mm). It is a uniform ionization ( |
