Introduction and function of D391K varistor

    Varistor is a SPD overvoltage protection device, which is an indispensable electronic component in power supply system. It has fast response rate, good absorbing ability of sudden wave, and good anti-burst function. Varistor 10D391K parameter varistor number: 1. Foot distance: 10 MMN 2. Potential difference can be continuously operated AC and DC: Vacanvn 300 V dcv / n 385. 3. Maximum surge capacity: 2500an.

So what are the functions of varistors?

    The most obvious characteristic of a varistor is that when the voltage attached to it is second only to its critical value "UN", the current intensity passing through it is very small, that is, a closed valve that increases rapidly through the current when the voltage is higher than the UN. The valve opens. Using this result, the special overvoltage can be restrained, and the protection circuit can not be harmed by the overvoltage. For example, the ZnO varistor is used in the power supply circuit of the electronic products that we use today. The voltage of the varistor applied here is 470V, when the transient burst voltage (non-uniform root value) exceeds 470V, Varistor is to show its clamp characteristics, reduce the excessive voltage, so that the back circuit to work in a safe limit.

The instantaneous power of the varistor is large, but the uniform sustained power is very small, so it can not be in the working condition for a long time.