How does Metal Oxide Varistor work?
Working Principle The term MOV or Metal Oxide Varistor is a variable resistor. But not like a potentiometer, its resistance will change automatically depending on its voltage. Once the voltage across the varistor increases, the resistance will be decreased.
What does a MOV do in an electrical circuit?
An MOV is a voltage dependent device which has an electrical behavior similar to back to back zener diodes. changes from a near open circuit to a very low value, thus clamping the transient voltage to a safe level. pulse is absorbed by the Varistor, thereby protecting vulnerable circuit components.
How do you choose a Metal Oxide Varistor?
Choose a varistor with an energy absorption rating that equals or slightly exceeds the energy values associated with the event the circuit may experience. If, however, the transient voltage is due to an external event, the magnitude of the source energy is unknown.
How do you use varistor in a circuit?
As such varistors are used in sensitive electronic circuits to ensure that if the voltage does suddenly exceeds a predetermined value, the varistor will effectively become a short circuit to protect the circuit that it shunts from excessive voltage as they are able to withstand peak currents of hundreds of amperes.
What is a metal oxide varistor used for?
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.
What are metal oxide varistors?
Metal Oxide Varistor’s are semiconductor devices who’s resistance changes from a very high open circuit condition to a very low short circuit condition to clamp any surge or voltage transient in an electrical circuit.
How do I select varistor value?
Select a model to provide the required voltage-clamping characteristic A final consideration is to choose the appropriate package style to suit the application. Consider the maximum continuous voltage that will be applied to the varistor including any high line conditions (i.e., 110% or more of nominal voltage).
How to choose the right metal oxide varistor (MOV)?
The first step of choosing a MOV is determining the continuous working voltage that will be provided across the varistor,you have to choose the varistor with maximum AC or
What does clamping voltage of a metal oxide varistor mean?
Clamping voltage is the maximum voltage allowed to pass through the circuitry to the connected equipment when tested with the UL test surge. 330 volts is the lowest rating allowed by the UL and the rating must be stated on the unit. The lower the number, the better. Other allowed ratings are 400, 600, 800, and 1000. Some manufacturers use a rating called “let through voltage” to
What is varistor diode?
Varistors are voltage dependent, nonlinear devices which have an electrical behavior similar to back-to-back zener diodes. The symmetrical, sharp breakdown characteristics shown in Figure 1 enable the varistor to provide excellent transient suppression performance.
Does metal oxide also produce oxygen?
pressure of oxygen will be in equilibrium with the metal and metal oxide at a given temperature. The significance of this is that, if the oxygen partial pressure is higher than the equilibrium value, the metal will be oxidized, and if it is lower than the equilibrium value then the oxide will be reduced.