is a non-linear voltage limiting resistor which is zinc oxide as the main component of the metal oxide semi-conductor
Work Principle of Varistor
Varistor works as a zinc oxide varistors and additives in certain conditions "sintering", the resistance will be strongly influenced by the voltage, the current increases sharply as the voltage rise and rise of the curve is a non-linear index. When the normal operating voltage, the varistor is in a high resistance state. When the surge arrives, it is in the path state, a strong current flows through the vent into the earth itself. After the surge, he immediately returned to the high resistance state.
Where Varistor are Often Used in?
is a quite extensive use of electronic components,
also it is the most widely used device of a transient disturbance absorption. The main electronic equipment that used it as following:
1. Power system
2. Mine wiring board
3. Security Systems
4. Motor Protection
5. Telecom Equipment
6. Automotive electronic systems
7. Home Appliances
The “Safety Value” Function of Varistor Circuit
What’s the function of electornic components - varistors? The biggest characteristic of varistor is while the added voltage on it is lower than its threshold, the current flowing through it is very small, which equivalents of a shut valve; and while the voltage exceeds the UN, the flow through it current surge, which equivalents of the valve open. Using this feature, you can often suppress the abnormal circuit over-voltage, and protect the circuit from damage of the over-voltage.