Metal Oxide Varistor Circuit

Metal oxide varistors movs are available in a variety of form factors and sizes for a broad range of applications.

Metal oxide varistor circuit. The radial leaded disc type is the most common version. Metal oxide varistor circuit. The energy of the incoming surge is partially conducted and partially absorbed protecting the circuit. 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.

Working of metal oxide varistor mov working of metal oxide varistor mov the working of a mov is shown in the figure above. The metal oxide varistor is designed to protect various types of electronic devices and semiconductor elements from switching and induced lightning surges. Metal oxide varistors or mov s are typically made from a small disk shaped metal zinc oxide material. The most common type is the mov or metal oxide varistor.

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. The circuit of the mov is shown below. Varistors are voltage dependent nonlinear devices which have electrical characteristics similar to back to back zener diodes. The main components used to protect the circuit are fuse and varistor.

The most common modern type of varistor is the metal oxide varistor mov. The circuit we will build is shown below. First let us consider the component to have an open circuit as shown in figure 1 a. 300vac metal oxide varistor.

The metal oxide varistor or mov is a voltage dependent nonlinear device that provides excellent transient voltage suppression. This mov circuit will clamp up to 300vac if a power surge allowing transients into the circuit were to be that high. The resistance of the mov is very high. When a high current passes through a mov its resistance value decreases and acts as a short.

The component starts conducting as soon as the voltage across it reaches the threshold voltage. The components needed to build this circuit are shown below. A metal oxide varistor is frequently used in different circuits along with a fuse. An mov s voltage rating called the varistor voltage is the voltage across a varistor when a current of 1ma is passed through the device.

They are available in many values for specific voltage ranges. These two are connected in parallel to the protected circuit. They are composed primarily of z n o with small additions of other metal oxides such as bismuth cobalt magnese and others. The boundary between each grain and a neighbor forms a diode junction which allows.