Two major categories of varistor

The use of varistor in different situations has different effects, so the requirements for varistor are also different. We need to pay attention to this problem when choosing, and use varistor correctly. The varistor can be classified into a varistor for protection and a varistor for circuit function, depending on the purpose of use.

1. It is a varistor for power protection, or a varistor for signal line and data line protection. They must meet the requirements of different technical standards.

2. According to the continuous working voltage applied to the varistor, the varistor across the power line can be divided into two types: AC or DC. The aging characteristics of the varistor under these two voltage stresses Performance is different.

3. According to the abnormal overvoltage characteristics of the varistor, the varistor can be divided into three types: surge suppression type, high power type and high energy type.

Surge suppression type: refers to a varistor used to suppress transient overvoltages such as lightning overvoltage and operating overvoltage. The occurrence of transient overvoltage is random, non-periodic, and the peak value of current and voltage may be very high. Big. Most varistors fall into this category.

High-power type: refers to the varistor used to absorb the continuous pulse group appearing in the cycle, for example, the varistor connected to the switching power converter, where the impulse voltage cycle occurs, and the period is known, the energy value can generally be calculated. When it comes out, the peak value of the voltage is not large, but because of the high frequency, the average power is quite large.

High-energy type: refers to a varistor that absorbs magnetic energy in a large inductor coil such as a generator excitation coil and a lifting electromagnet coil. For such applications, the main technical indicator is energy absorption capability.