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The circuit is the safe place for the stable operation of electrical appliances in our life. There are many types and forms of circuits, and various protective elements are often used in circuits to ensure the power supply. So what is an overcurrent protection circuit? Let's take a look.

MOV varistor principle: When the voltage applied to the MOV varistor is lower than its threshold, the current flowing through it is small, equivalent to a resistance infinite resistance. That is, when the voltage applied to it is below its threshold, it is equivalent to a switch in the off state. When the voltage applied to the rheostat exceeds its threshold, the current flowing through it increases dramatically, which corresponds to a resistance with very little resistance. That is, when the voltage applied to it is higher than its threshold, it is equivalent to a switch in the closed state.

Varistors are widely used in electronic circuits to protect them from possible damage caused by transient voltage changes in the power supply system. Varistor is generally used in parallel in the circuit, when the voltage at both ends of the resistance changes dramatically, the resistance short circuit will fuse the current, play a protective role. Varistor in the circuit, often used for power supply overvoltage protection and voltage regulation. When the high voltage comes, the resistance of the varistor is reduced and the current is shunt to prevent excessive instantaneous voltage damage or interference. Thus, sensitive electronic components are protected.

MOV varistor is mainly used for surge protection of low-voltage electrical appliances, most of which are zinc oxide rheostat. It is a polycrystalline semiconductor ceramic component made of zinc oxide, doped with various metal oxides, and using typical electronic ceramic technology. The rheostat has a symmetrical voltammetry characteristic curve, and the current flowing through the MOV increases exponentially as the voltage at both ends of the MOV increases.