This contains a mass of zinc oxide grains, in a matrix of other metal oxides, sandwiched between two metal plates (the electrodes). 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. It is used to protect the circuit from high voltage spikes by varying its resistance. Your email address will not be published.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. In order to have good electrical contacts, the contacts of the material are metallized with silver or copper. As the voltage increases and reaches clamping voltage i.e., the rated voltage, the current now increases. It is always placed in shunt with the device being protected. Varistor je skraćenica od varijabilni rezistor, odnosno promenljivi otpornik It's currently part of the 12v input on an electric fence energiser. The electrical characteristics of the device are dependent on temperature provided and atmospheric conditions. plus, I didn't see anything that could change the resistance. 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. So I'm not sure if it is a varistor or if it just has obscure markings. Your email address will not be published. It changes value dependent on the current draw and operates by changing its value as the resistor's temperature changes. n a two-electrode semiconductor device … Varistor also known as Voltage Dependent Resistor (VDR) is a passive two-terminal solid state semiconductor device that is used to provide protection to electrical and electronic circuits from overcurrent situations. so, what is a varistor? Transient voltages are high-magnitude spikes of … 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. The varistor is a voltage limiting type protection device. Due to the high resistance offered by it. Varistors act as capacitors too, but the values generally differ from what would be expected of a capacitor with the same marking. what does a varistor do? 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The resistor body material of the varistor is a semiconductor, which is a voltage-limiting protection device. A "varistor" is a resistance device with non-linear volt-ampere characteristics. Thus we can see a linear relationship between voltage and current. varistor synonyms, varistor pronunciation, varistor translation, English dictionary definition of varistor. The word varistor is formed by the combining variable and resistor. They are also known by the name VDR [voltage dependent resistor] and have non-ohmic characteristics. They are voltage dependent, nonlinear devices that provide transient... Metal oxide varistors, also known as MOVs are one of the most common types of varistors. But the resistance drops rapidly with the increase in voltage above rated voltage. Their resistance decreases when the voltage increases. It means it is a variable resistance. Varistor. The basic difference between a normal resistor and a voltage-dependent resistor is that would the resistance of a resistor can be altered only by manual action but we can alter the resistance by altering the voltage. See more. In contrast to a diode however, it has the same characteristic for both directions of traversing current. Understanding the specifics of what … To assure reliable operation, transient voltage suppression should be considered at early stages of the design process. Varistor Voltage-Current Characteristics . The figure below shows the symbolic representation of a varistor: These are basically used to protect the circuit from high voltage fluctuations. 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. 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 … It controls the current depending on the voltage.. Voltage / Current / Temperature Protection Devices > Voltage Protection Devices > Chip Varistors / Ceramic Transient Voltage Suppressors. A varistor has the volt-ampere characteristics in which current suddenly starts to flow through the device at a certain voltage, as shown in Figure 1. Thus we can see that the resistance has become very low and large current is flowing through it even after the voltage is limited after the rated voltage. In AC protection and cable TV surge protection etc. Voltage / Current / Temperature Protection Devices > Voltage Protection Devices > Chip Varistors / Ceramic Transient Voltage Suppressors. 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