Metal Oxide Varistor

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.

Metal oxide varistor.

The boundary between each grain and a neighbor forms a diode junction which allows. The metal oxide varistor or mov for short is a voltage dependant resistor in which the resistance material is a metallic oxide primarily zinc oxide zno pressed into a ceramic like material. Mov is the most commonly used type of varistor. Metal oxide varistors are similar to resistors and has only two leads.

Metal oxide varistors are also connected in series to supply high voltage ratings. Varistors are voltage dependent nonlinear devices which have electrical characteristics similar to back to back zener diodes. But not like a potentiometer its resistance will change automatically depending on its voltage. This type contains a ceramic mass of zinc oxide grains in a matrix of other metal oxides such as small amounts of bismuth cobalt manganese oxides sandwiched between two metal plates which constitute the electrodes of the device.

There will also be a presentation of the different mov products littlefuse brings to the marketplace. When a high current passes through a mov its resistance value decreases and acts as a short. The metal oxide varistor or mov is. Metal oxide varistors and multi layered varistors.

This tutorial will provide an introduction to metal oxide varistors and mov product offerings from littelfuse. The term mov or metal oxide varistor is a variable resistor. Once the voltage across the varistor increases the resistance will be decreased. 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.

Metal oxide varistor is a voltage dependent resistor. Metal oxide varistor basics. Metal oxide varistors consist of approximately 90 zinc oxide as a ceramic base material plus other filler materials for the formation of junctions. Basic operation electrical characteristics and applications will be discussed.

The metal oxide varistor or mov is a voltage dependent nonlinear device that provides excellent transient voltage suppression. The metal oxide varistor is designed to protect various types of electronic devices and semiconductor elements from switching and induced lightning surges. There is no polarity for these leads and hence can be connected in both directions. The most common modern type of varistor is the metal oxide varistor mov.

Metal oxide varistors littelfuse inc. They are composed primarily of z n o with small additions of other metal oxides such as bismuth cobalt magnese and others.