Application of varistor:
1. Avoid lightning strikes
When encountering thunderstorm weather, we know that the instantaneous voltage of lightning strikes can reach 100 ～ 10000V, which causes great harm. Therefore, it is necessary to adopt methods for important electrical equipment to avoid lightning strikes. The method of parallel connection of varistor and equipment can be used to maintain electrical equipment well.
2. Avoid damage to equipment caused by overvoltage
Operating over-voltage is a kind of over-voltage generated during the rapid change of electromagnetic energy when the circuit operation state changes suddenly and is released quickly. To avoid this over-voltage, a varistor can be used, which can maintain various power supply equipment, motors, etc. .
3. Overvoltage maintenance of semiconductor devices.
In order to avoid the semiconductor device from being burned when an overvoltage occurs due to some reasons, the varistor is commonly used for maintenance. The varistor is connected between the emitter and collector of the transistor or the transformer at one time, which can effectively maintain the overvoltage. Damage to the transistor.
Fourth, contactor, relay protector.
When the circuit containing inductive loads such as contactors and relays is cut off, the overvoltage can exceed several times of the power supply voltage. The overvoltage forms arc and spark discharge between the contacts, burning the contacts and shortening the equipment life. Because of the shunt effect of the varistor at a high potential, the contacts are then maintained to avoid damage to the contactor and relay.