Metal-oxide varistor manufactured by Siemens & Halske AG.Modern varistor schematic symbol, which is the same as a thermistor symbol[1]
A varistor (a.k.a. voltage-dependent resistor (VDR)) is a surge protecting electronic component with an electrical resistance that varies with the applied voltage.[2] It has a nonlinear, non-ohmic current–voltage characteristic that is similar to that of a diode. Unlike a diode however, it has the same characteristic for both directions of traversing current. Traditionally, varistors were indeed constructed by connecting two rectifiers, such as the copper-oxide or germanium-oxide rectifier in antiparallel configuration. At low voltage the varistor has a high electrical resistance which decreases as the voltage is raised. Modern varistors are primarily based on sintered ceramic metal-oxide materials which exhibit directional behavior only on a microscopic scale. This type is commonly known as the metal-oxide varistor (MOV).
Varistors are used as control or compensation elements in circuits either to provide optimal operating conditions or to protect against excessive transient voltages. When used as protection devices, they shunt the current created by the excessive voltage away from sensitive components when triggered.
The name varistor is a portmanteau of varying resistor. The term is only used for non-ohmic varying resistors. Variable resistors, such as the potentiometer and the rheostat, have ohmic characteristics.
^"Standards for Resistor Symbols". EePower. EETech Media. Retrieved September 13, 2021.
^Bell Laboratories (1983). S. Millman (ed.). A History of Engineering and Science in the Bell System, Physical Science (1925–1980)(PDF). AT&T Bell Laboratories. p. 413. ISBN 0-932764-03-7.
A varistor (a.k.a. voltage-dependent resistor (VDR)) is a surge protecting electronic component with an electrical resistance that varies with the applied...
spark gaps, discharge tubes, zener-type semiconductors, and metal-oxide varistors (MOVs), all of which begin to conduct current once a certain voltage threshold...
filename extension for the QuickTime multimedia file format Metal oxide varistor, an electronic component with a significant non-ohmic current-voltage characteristic...
the words "transconductance" or "transfer", and "varistor". The device logically belongs in the varistor family, and has the transconductance or transfer...
(ANSI) Thermistor (ANSI). Use -t for NTC symbol. Use +t for PTC symbol. Varistor (ANSI) General capacitor (IEC-style) Polarized capacitor (American-style)...
that device. An avalanche diode, transient voltage suppression diode, varistor, overvoltage crowbar, or a range of other overvoltage protective devices...
an RC network. In some DC circuits, a varistor made of inexpensive metal oxide, called a metal oxide varistor (MOV) is used. They may be unipolar or...
companies established here at Hoodi during 2018 to 2021 which are SolarClue, Varistor Technologies Pvt Ltd, Fabzen, Milmila and many more. Hoodi has a government...
the words "transconductance" or "transfer", and "varistor". The device logically belongs in the varistor family, and has the transconductance or transfer...
Electric for the silicon carbide composite used in their arrester and varistor products. Some spark gaps are open to the air, but most modern varieties...
as a discolored dielectric or as a locally melted anode. Metal oxide varistors typically have lower resistance as they heat up; if connected directly...
fuses. They will also include high energy overvoltage MOV (Metal Oxide Varistor) protection, and circuit over-current protection in the form of a Polyswitch...
show grain boundary effects. One of the most widely used of these is the varistor. These are devices that exhibit the property that resistance drops sharply...
transistor die and the heatsink. See also Thermal Design Power. Metal oxide varistors typically develop lower resistance as they heat up. If connected directly...
Global Information
