The various symbols commonly used for varistors are given hereunder. Looking for online definition of VARISTOR or what VARISTOR stands for? Due to the high resistance offered by it. It controls the current depending on the voltage.. Varistors provide reliable and economical protection against high voltage transients and surges which may be produced, for example, by lightning, switching or electrical noise on AC or DC power lines. Find the number code on the part and check to see if the device capacitance is a match. Varistors provide over voltage protection to electrical and electronic circuits in contrast to circuit breakers or fuse which provide protection to … The word "varistor" is derived from variable resistor. What does a varistor do? [Click the image to enlarge it] A Metal Oxide Varistor (MOV) is a protection component used in power supply circuits that is powered directly from AC mains. It is called so as the component is made from a mixture of zinc oxide and other metal oxides like cobalt, manganese and so on and is kept intact between two electrodes which are basically metal plates. The figure below shows a disc type varistor: Nowadays these are the most common voltage clampers and can be used for a wide range of voltage. Here as we can see that when the voltage is low then the resistance across it is high. Voltage / Current / Temperature Protection Devices > Voltage Protection Devices > Chip Varistors / Ceramic Transient Voltage Suppressors. Usually, zinc oxide is used in its manufacturing thus is also known as metal oxide varistor. The figure below shows the current versus voltage characteristic of a varistor: Here, as we can see that until the clamping voltage is reached, the device remains in the non-conducting state. Metaloxid varistor. So, after this voltage, the device which is till now behaving as an insulator now starts behaving as a conductor. The figure below shows the structure of metal oxide varistor: Here the varistor is formed 90% with zinc oxide and the rest is filler material that forms the junction. Using the non-linear characteristics of the varistor, when an overvoltage occurs between the two poles of the varistor, the varistor can clamp the voltage to a relatively fixed voltage value, thereby protecting the latter circuit. The ability of the varistor to limit the transient voltage is sometimes expressed in terms of a clamp ratio. Voltage / Current / Temperature Protection Devices > Voltage Protection Devices > Chip Varistors / Ceramic Transient Voltage Suppressors. Also known as a voltage-dependent resistor (VDR), it has a nonlinear, non-ohmic current–voltage characteristic that is similar to that of a diode. It is basically a non-ohmic resistor that does not follow Ohm’s law and hence it is also called a non-linear resistor or a voltage-dependent resistor. Varistors are mainly used for transient over-voltage protection in circuits, but because of their similar volt-ampere characteristics to semiconductor regulators, they also have a variety of circuit component functions. Any two-terminal solid-state device in which the electric current I increases considerably faster than the voltage V.This nonlinear effect may occur over … Your email address will not be published. A varistor that is made with a combination of zinc oxide & other kinds of metal oxides such as manganese, cobalt, etc is known as metal oxide varistor. It is generally specified to be DC1mA. A varistor, VDR, (voltage dependent resistor) is a type of resistor. It is used to protect the circuit from high voltage spikes by varying its resistance. Metal Oxide Varistor – Basics. It provides excellent overvoltage protection. It is mainly used to clamp the voltage when the circuit is subjected to overvoltage and absorb excess current to protect sensitive devices. The ability of the varistor to limit the transient voltage is sometimes expressed in terms of a clamp ratio. Varistors are components which protect electronic circuitry from excess power such as that offered in the case of transient voltages. Figure 9 shows a graph of current versus voltage for a zinc oxide varistor used in household electronics. Define varistor. As nouns the difference between varistor and thermistor is that varistor is an electronic component having a variable resistance; used to protect circuits against power surges while thermistor is a resistor whose resistance varies rapidly and predictably with temperature and … In contrast to a diode however, it has the same characteristic for both directions of traversing current. The varistors are used to protect semiconductor devices in electronic and electric circuits from overvoltage. Other articles where Varistor is discussed: crystal: Conducting properties of semiconductors: This material is called a varistor, which is a contraction of the words variable and resistor. The terminal voltage between both terminals of a varistor when a specified current is passed through the varistor. A varistor is an electronic component that protects expensive devices from harmful power surges, much like a shock absorber. They are also known by the name VDR [voltage dependent resistor] and have non-ohmic characteristics. The word is composed of parts of the words “ var iable res istor. A varistor is a variable resistor. A "varistor" is a resistance device with non-linear volt-ampere characteristics. varistor model curve gives the varistor transient current and the value of clamped peak transient voltage. varistor model curve gives the varistor transient current and the value of clamped peak transient voltage. The effect of a varistor … What is varistor voltage? The figure below shows resistance versus voltage curve for a varistor: Varistors exhibit unusual behaviour in case of resistance. Varistor. A metal oxide varistor is a device used as a component in electrical equipment.The word varistor is short for variable resistor.A resistor is a circuit that does not conduct electricity well. In AC protection and cable TV surge protection etc. Varistors Varistors have a non-linear resistance which is dependent on the voltage over the varistor. A varistor does not obey Ohm’s law and hence it is not like an ohmic resistor. varistor protects the electrical and electronic device from overvoltage transients it is a two-terminal semiconductor device and its resistance is depended on its input voltage it is a passive two-terminal semiconductor device. Asit is voltage-dependent it is also called voltage-dependent resistor or VDR. Varistor – Static Resistance VS Voltage Working of a Varistor. The word varistor is formed by the combining variable and resistor. Varistor. Varistor is a passive nonlinear two terminal solid state semiconductor device. Varistors, also called metal-oxide varistors (MOVs), are used to protect sensitive circuits from a variety of overvoltage conditions. Definition: The most commonly used form of a varistor is the Metal Oxide Varistor, which is also a voltage dependant and non-linear resistor connected to the electrical and electronic circuits to protect against the switch, lightning surges, and to achieve high suppression of transient voltage. A Metal Oxide Varistor or MOV is the blue or orange-colored circular component that you can commonly spot on the AC Input side of any Power Supply Circuit.The Metal Oxide Varistor can be considered as another type of variable resistor that can vary its resistance based on the applied voltage across it. A Varistor is a varying resistor whose resistance depends on the applied voltage. These types of varistors protect from heavy devices from transient voltages. Transient voltages are high-magnitude spikes of … Difference Between Half Wave and Full Wave Rectifier, Difference between Half Adder and Full Adder, Difference between Centre Tapped and Bridge Rectifier, Intelligent Electronic Devices (IED) in SCADA. Varistors are formed when crystals of silicon carbide or metal oxides are pressed into a ceramic material. A metal oxide varistor, or MOV, protects sensitive electronic equipment from voltage spikes in the power line. Definition: A varistor is a 2 terminal semiconductor device that protects the electrical and electronic devices from overvoltage transients. Voltage / Current / Temperature Protection Devices > Voltage Protection Devices > Chip Varistors / Ceramic Transient Voltage Suppressors. The markings are : 05 K385 1146 I know the k385 is the voltage from what I can find, but have no idea what the current is or what part number it matches up with. 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