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Transient-voltage-suppression Diode
A transient-voltage-suppression (TVS) diode, also transil, transorb or thyrector, is an electronic component used to protect electronics from voltage spikes induced on connected wires. Description The device operates by shunting excess current when the induced voltage exceeds the avalanche breakdown potential. It is a clamp (circuit), clamping device, suppressing all overvoltages above its breakdown voltage. It automatically resets when the overvoltage goes away, but absorbs much more of the transient energy internally than a similarly rated crowbar (circuit), crowbar device. A transient-voltage-suppression diode may be either unidirectional or bidirectional. A unidirectional device operates as a rectifier in the forward direction like any other avalanche diode, but is made and tested to handle very large peak currents. A bidirectional transient-voltage-suppression diode can be represented by two mutually opposing avalanche diodes in series with one another and connected in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passivity (engineering)
Passivity is a property of engineering systems, most commonly encountered in analog electronics and control systems. Typically, analog designers use ''passivity'' to refer to incrementally passive components and systems, which are incapable of Gain (electronics), power gain. In contrast, control systems engineers will use ''passivity'' to refer to thermodynamically passive ones, which consume, but do not produce, energy. As such, without context or a qualifier, the term ''passive'' is ambiguous. An electronic circuit consisting entirely of passive components is called a passive circuit, and has the same properties as a passive component. If a device is ''not'' passive, then it is an active device. Thermodynamic passivity In control systems and circuit network theory, a passive component or circuit is one that consumes energy, but does not produce energy. Under this methodology, voltage source, voltage and current sources are considered active, while resistors, capacitors, ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transient Voltage Suppressor
A surge protector, spike suppressor, surge suppressor, surge diverter, surge protection device (SPD), transient voltage suppressor (TVS) or transient voltage surge suppressor (TVSS) is an appliance or device intended to protect electrical devices in alternating current (AC) circuits from voltage spikes with very short duration measured in microseconds, which can arise from a variety of causes including lightning strikes in the vicinity. A surge protector limits the voltage supplied to the electrical devices to a certain threshold by short-circuiting current to ground or absorbing the spike when a transient occurs, thus avoiding damage to the devices connected to it. Key specifications that characterize this device are the clamping voltage, or the transient voltage at which the device starts functioning, the Joule rating, a measure of how much energy can be absorbed per surge, and the response time. Definitions The terms ''surge protection device'' (''SPD'') and ''transien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trisil
Trisil is a trade name for a thyristor surge protection device, an electronic component designed to protect electronic circuits from overvoltage. Unlike a transient voltage suppression diodes, such as Transil, Trisil acts as a crowbar device, switching ON when the voltage across it exceeds its breakover voltage. Overview A Trisil is bidirectional, behaving the same way in both directions. It is principally a voltage-controlled triac without gate. The behavior of a Trisil is similar to a SIDAC, but unlike SIDAC, Trisil devices are commonly used to protect circuits from overvoltage.They act faster and can handle more current. In 1982, the only manufacturer was Thomson SA; a successor company, ST Microelectronics continues to make the devices. This type of crowbar protector is widely used to protect telecom equipment from lightning-induced transients and power line-induced currents. Other manufacturers of similar devices include Bourns (TISP) and Littelfuse (SIDACtor). Instead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Sink
A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is thermal management (electronics), dissipated away from the device, thereby allowing regulation of the device's temperature. In computers, heat sinks computer cooling, are used to cool central processing unit, CPUs, graphics processing unit, GPUs, and some chipsets and RAM modules. Heat sinks are used with other high-power semiconductor devices such as Transistor#Other transistor types, power transistors and optoelectronics such as lasers and light-emitting diodes (LEDs), where the heat dissipation ability of the component itself is insufficient to moderate its temperature. A heat sink is designed to maximize its surface area in contact with the cooling medium surrounding it, such as the air. Air velocity, choice of material, protrusion design and surface treatment are fact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic Inductance
In electrical networks, a parasitic impedance is a circuit element ( resistance, inductance or capacitance) which is not desirable in an electrical component for its intended purpose. For instance, a resistor is designed to possess resistance, but will also possess unwanted parasitic capacitance. Parasitic impedances are unavoidable. All conductors possess resistance and inductance and the principles of duality ensure that where there is inductance, there will also be capacitance. Component designers will strive to minimise parasitic elements but are unable to eliminate them. Discrete components will often have some parasitic values detailed on their datasheets to aid circuit designers in compensating for unwanted effects. The most commonly seen manifestations of parasitic impedances in components are in the parasitic inductance and resistance of the component leads and the parasitic capacitance of the component packaging. For wound components such as inductors and transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitor
In electrical engineering, a capacitor is a device that stores electrical energy by accumulating electric charges on two closely spaced surfaces that are insulated from each other. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the '' condenser microphone''. It is a passive electronic component with two terminals. The utility of a capacitor depends on its capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed specifically to add capacitance to some part of the circuit. The physical form and construction of practical capacitors vary widely and many types of capacitor are in common use. Most capacitors contain at least two electrical conductors, often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconductin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic Capacitance
Parasitic capacitance or stray capacitance is the unavoidable and usually unwanted capacitance that exists between the parts of an electronic component or circuit simply because of their proximity to each other. When two electrical conductors at different voltages are close together, the electric field between them causes electric charge to be stored on them; this effect is capacitance. All practical circuit elements such as inductors, diodes, and transistors have internal capacitance, which can cause their behavior to depart from that of ideal circuit elements. Additionally, there is always some capacitance between any two conductors; this can be significant with closely spaced conductors, such as adjacent wires or printed circuit board traces. The parasitic capacitance between the turns of an inductor (e.g. Figure 1) or other wound component is often described as ''self-capacitance''. However, in electromagnetics, the term self-capacitance more correctly refers to a diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampere
The ampere ( , ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 coulomb (C) moving past a point per second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagnetism along with Danish physicist Hans Christian Ørsted. As of the 2019 revision of the SI, the ampere is defined by fixing the elementary charge to be exactly , which means an ampere is an electric current equivalent to elementary charges moving every seconds, or approximately elementary charges moving in a second. Prior to the redefinition, the ampere was defined as the current passing through two parallel wires 1 metre apart that produces a magnetic force of newtons per metre. The earlier CGS system has two units of current, one structured similarly to the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clamping Voltage
A wheel clamp, also known as wheel boot, parking boot, or Denver boot, is a device that is designed to prevent motor vehicles from being moved. In its most common form, it consists of a clamp that surrounds a vehicle wheel, designed to prevent removal of both itself and the wheel. In the United States, the device became known as a "Denver boot" after the city of Denver, Colorado, which was the first place in the country to employ them, mostly to force the payment of outstanding parking tickets. While primarily associated with law enforcement and parking violations, a variety of wheel clamps are now available to consumers as theft deterrent devices for personal use as an alternative to the steering-wheel lock. Functions Wheel clamps have five main functions: * To punish unauthorised or illegal parking, in lieu of towing the offending vehicle; in these cases, police or property owners who place the clamp may charge a high "release fee" to remove it * To enforce unpaid fines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breakdown Voltage
The breakdown voltage of an insulator (electrical), insulator is the minimum voltage that causes a portion of an insulator to experience electrical breakdown and become electrically Conductor (material), conductive. For diodes, the breakdown voltage is the minimum reverse voltage that makes the diode conduct appreciably in reverse. Some devices (such as TRIACs) also have a ''forward breakdown voltage''. Electrical breakdown Materials are often classified as electrical conductor, conductors or Insulator (electricity), insulators based on their resistivity. A conductor is a substance which contains many mobile charged particles called charge carriers which are free to move about inside the material. An electric field is created across a piece of the material by applying a voltage difference between electrical contacts on different sides of the material. The force of the field causes the charge carriers within the material to move, creating an electric current from the positive co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maximum Reverse Standoff Voltage
In mathematical analysis, the maximum and minimum of a function are, respectively, the greatest and least value taken by the function. Known generically as extremum, they may be defined either within a given range (the ''local'' or ''relative'' extrema) or on the entire domain (the ''global'' or ''absolute'' extrema) of a function. Pierre de Fermat was one of the first mathematicians to propose a general technique, adequality, for finding the maxima and minima of functions. As defined in set theory, the maximum and minimum of a set are the greatest and least elements in the set, respectively. Unbounded infinite sets, such as the set of real numbers, have no minimum or maximum. In statistics, the corresponding concept is the sample maximum and minimum. Definition A real-valued function ''f'' defined on a domain ''X'' has a global (or absolute) maximum point at ''x''∗, if for all ''x'' in ''X''. Similarly, the function has a global (or absolute) minimum point at ''x''∗, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leakage Current
In electronics, leakage is the gradual transfer of electrical energy across a boundary normally viewed as insulating, such as the spontaneous discharge of a charged capacitor, magnetic coupling of a transformer with other components, or flow of current across a transistor in the "off" state or a reverse-polarized diode. In capacitors Gradual loss of energy from a charged capacitor is primarily caused by electronic devices attached to the capacitors, such as transistors or diodes, which conduct a small amount of current even when they are turned off. Even though this off current is an order of magnitude less than the current through the device when it is on, the current still slowly discharges the capacitor. Another contributor to leakage from a capacitor is from the undesired imperfection of some dielectric materials used in capacitors, also known as ''dielectric leakage''. It is a result of the dielectric material not being a perfect insulator and having some non-zero cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
