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Power Module
A power module or power electronic module provides the physical containment for several power components, usually power semiconductor devices. These power semiconductors (so-called dies) are typically soldered or sintered on a power electronic substrate that carries the power semiconductors, provides electrical and thermal contact and electrical insulation where needed. Compared to discrete power semiconductors in plastic housings as TO-247 or TO-220, power packages provide a higher power density and are in many cases more reliable. History Power modules trace their roots to the mid-20th century, when power switching was handled by discrete bipolar junction transistors (BJTs) and, later, a Darlington pair mounted in screw-terminal packages. These early assemblies offered high current gain but suffered from bulky form factors, limited thermal performance, and complex wiring. In 1974, Semikron introduced the SemiPack 1, the first commercially available “potential-free” h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IGBT 3300V 1200A Mitsubishi
An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily forming an electronic switch. It was developed to combine high efficiency with fast switching. It consists of four alternating layers (NPNP) that are controlled by a metal–oxide–semiconductor (MOS) gate structure. Although the structure of the IGBT is topologically similar to a thyristor with a " MOS" gate ( MOS-gate thyristor), the thyristor action is completely suppressed, and only the transistor action is permitted in the entire device operation range. It is used in switching power supplies in high-power applications: variable-frequency drives (VFDs) for motor control in electric cars, trains, variable-speed refrigerators, and air conditioners, as well as lamp ballasts, arc-welding machines, photovoltaic and hybrid inverters, uninterruptible power supply systems (UPS), and induction stoves. Since it is designed to turn on and off rapidly, the IGBT can synthesize complex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freewheeling Diode
A flyback diode (also called freewheeling diode) is any diode connected across an inductor used to eliminate flyback, which is the sudden voltage spike seen across an inductive load when its supply current is suddenly reduced or interrupted. It is used in circuits in which inductive loads are controlled by switches, and in switching power supplies and inverters. Flyback circuits have been used since 1930 and were refined starting in 1950 for use in television receivers. The word ''flyback'' comes from the horizontal movement of the electron beam in a cathode ray tube, because the beam flew back to begin the next horizontal line. This diode is known by many other names, such as snubber diode, commutating diode, freewheeling diode, suppressor diode, clamp diode, or catch diode. Operation Fig. 1 shows an inductor connected to a battery - a constant voltage source. The resistor represents the small static resistance of the inductor's wire windings. When the switch is closed, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge Rectifier
A diode bridge is a bridge rectifier circuit of four diodes that is used in the process of converting alternating current (AC) from the input terminals to direct current (DC, i.e. fixed polarity) on the output terminals. Its function is to convert the negative voltage portions of the AC waveform to positive voltage, after which a low-pass filter can be used to smooth the result into DC. When used in its most common application, for conversion of an alternating-current (AC) input into a direct-current (DC) output, it is known as a bridge rectifier. A bridge rectifier provides full-wave rectification from a two-wire AC input, resulting in lower cost and weight as compared to a rectifier with a three-wire input from a transformer with a center-tapped secondary winding. Prior to the availability of integrated circuits, a bridge rectifier was constructed from separate diodes. Since about 1950, a single four-terminal component containing the four diodes connected in a bridge con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diode
A diode is a two-Terminal (electronics), terminal electronic component that conducts electric current primarily in One-way traffic, one direction (asymmetric electrical conductance, conductance). It has low (ideally zero) Electrical resistance and conductance, resistance in one direction and high (ideally infinite) resistance in the other. A semiconductor diode, the most commonly used type today, is a Crystallinity, crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals. It has an Exponential function, exponential current–voltage characteristic. Semiconductor diodes were the first Semiconductor device, semiconductor electronic devices. The discovery of asymmetric electrical conduction across the contact between a Crystal, crystalline mineral and a metal was made by German physicist Ferdinand Braun in 1874. Today, most diodes are made of silicon, but other semiconducting materials such as gallium arsenide and germanium are also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiparallel (electronics)
In electronics, two anti-parallel or inverse-parallel devices are connected in parallel but with their polarities reversed. One example is the TRIAC, which is comparable to two thyristors connected back-to-back (in other words, reverse parallel), but on a single piece of silicon. Two LEDs can be paired this way, so that each protects the other from reverse voltage. A series string of such pairs can be connected to AC or DC power, with an appropriate resistor. Some two-color LEDs are constructed this way, with the 2 dies connected anti-parallel in one chip package. With AC, the LEDs in each pair take turns emitting light, on alternate half-cycles of supply power, greatly reducing the strobing effect to below the normal flicker fusion threshold of the human eye The human eye is a sensory organ in the visual system that reacts to light, visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and Balance (ability), keeping balance. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermistor
A thermistor is a semiconductor type of resistor in which the resistance is strongly dependent on temperature. The word ''thermistor'' is a portmanteau of ''thermal'' and ''resistor''. The varying resistance with temperature allows these devices to be used as temperature sensors, or to control current as a function of temperature. Some thermistors have decreasing resistance with temperature, while other types have increasing resistance with temperature. This allows them to be used for limiting current to cold circuits, e.g. for inrush current protection, or for limiting current to hot circuits, e.g. to prevent thermal runaway. Thermistors are categorized based on their conduction models. ''Negative-temperature-coefficient'' (NTC) thermistors have ''less'' resistance at ''higher'' temperatures, while ''positive-temperature-coefficient'' (PTC) thermistors have ''more'' resistance at ''higher'' temperatures. NTC thermistors are widely used as inrush current limiters and temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JFET
The junction field-effect transistor (JFET) is one of the simplest types of field-effect transistor. JFETs are three-terminal semiconductor devices that can be used as electronically controlled switches or resistors, or to build amplifiers. Unlike bipolar junction transistors, JFETs are exclusively voltage-controlled in that they do not need a biasing current. Electric charge flows through a semiconducting channel between ''source'' and ''drain'' terminals. By applying a reverse bias voltage to a ''gate'' terminal, the channel is '' pinched'', so that the electric current is impeded or switched off completely. A JFET is usually conducting when there is zero voltage between its gate and source terminals. If a potential difference of the proper polarity is applied between its gate and source terminals, the JFET will be more resistive to current flow, which means less current would flow in the channel between the source and drain terminals. JFETs are sometimes referred to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gate Turn-off Thyristor
A gate turn-off thyristor (GTO) is a type of high-power (e.g. 1200 V AC) thyristor that unlike a normal thyristor is fully controllable and can be turned On and Off by their gate lead. It was invented by General Electric. Device description Normal thyristors ( silicon-controlled rectifiers) are not fully controllable switches (a fully controllable switch can be turned on and off at will). Thyristors can only be turned on using the gate lead, but cannot be turned off using the gate lead. Thyristors are switched on by a gate signal, but even after the gate signal is de-asserted (removed, reverse biased), the thyristor remains in the on state until a turn-off condition occurs (which can be the application of a reverse voltage to the terminals or a decrease of the forward current below a certain threshold value known as the ''holding current''). Thus, a thyristor behaves like a normal semiconductor diode after it is turned on, or ''fired''. The GTO can be turned on by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyristor
A thyristor (, from a combination of Greek language ''θύρα'', meaning "door" or "valve", and ''transistor'' ) is a solid-state semiconductor device which can be thought of as being a highly robust and switchable diode, allowing the passage of current in one direction but not the other, often under control of a gate electrode, that is used in high power applications like inverters and radar generators. It usually consists of four layers of alternating P- and N-type materials. It acts as a bistable switch (or a latch). There are two designs, differing in what triggers the conducting state. In a three-lead thyristor, a small current on its gate lead controls the larger current of the anode-to-cathode path. In a two-lead thyristor, conduction begins when the potential difference between the anode and cathode themselves is sufficiently large (breakdown voltage). The thyristor continues conducting until the voltage across the device is reverse-biased or the voltage is removed (b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOSFET
upright=1.3, Two power MOSFETs in amperes">A in the ''on'' state, dissipating up to about 100 watt">W and controlling a load of over 2000 W. A matchstick is pictured for scale. In electronics, the metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, MOS FET, or MOS transistor) is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, the voltage of which determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. The term ''metal–insulator–semiconductor field-effect transistor'' (''MISFET'') is almost synonymous with ''MOSFET''. Another near-synonym is ''insulated-gate field-effect transistor'' (''IGFET''). The main advantage of a MOSFET is that it requires almost no input current to control the load current under steady-state or low-frequency conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schottky Barrier Diode
The Schottky diode (named after the German physicist Walter H. Schottky), also known as Schottky barrier diode or hot-carrier diode, is a semiconductor diode formed by the junction of a semiconductor with a metal. It has a low forward voltage drop and a very fast switching action. The cat's-whisker detectors used in the early days of wireless and metal rectifiers used in early power applications can be considered primitive Schottky diodes. When sufficient forward voltage is applied, a current flows in the forward direction. A silicon p–n diode has a typical forward voltage of 600–700 mV, while the Schottky's forward voltage is 150–450 mV. This lower forward voltage requirement allows higher switching speeds and better system efficiency. Construction A metal–semiconductor junction is formed between a metal and a semiconductor, creating a Schottky barrier (instead of a semiconductor–semiconductor junction as in conventional diodes). Typical metals used are moly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Carbide
Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite. Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and Cat's whisker detector, detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both. Natural occurrence Naturally occurring moissanite is found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
