Different applications, the application of the purpose of varistor, the role of the varistor voltage / current should not be the same, so the requirements of the varistor is not the same, pay attention to distinguish this difference, for the correct use is very important of.
According to the purpose of the use of varistor can be divided into two categories: ① protection with varistor, ② circuit function with varistor.
Protection resistance
(1) distinguish between power supply protection varistors, or signal lines, data line protection with varistors, they have to meet the requirements of different technical standards.
(2) Depending on the continuous operating voltage applied to the varistor, the varistor across the power supply line can be divided into two types of AC or DC, and the varistor is aged under these two kinds of voltage stresses Features are different.
(3) According to the varistor to withstand the abnormal over-voltage characteristics of different varistors can be divided into surge suppression, high power and high energy type of these three types.
★ Surge suppression type: refers to the suppression of lightning overvoltage and over-voltage and other transient over-voltage varistor, the emergence of this transient over-voltage is random, non-periodic, the current peak voltage may Very big. Most varistors all fall into this category.
★ high power type: refers to the absorption cycle for the emergence of continuous pulse group varistor, such as in the switching power supply transformer on the varistor, where the impact voltage cycle occurs, and the cycle can be seen, the energy value can generally Calculated, the peak voltage is not large, but the frequency is high, the average power is quite large.
★ high-energy type: refers to the absorption of generator excitation coil, lifting solenoid coil and other large inductor coil in the magnetic energy of the voltage transformer, for such applications, the main technical indicators of energy absorption capacity. Varistor protection, the vast majority of applications, it can be repeated many times, but sometimes it made it as a current fuse as a "one-time" protection device. Such as a short-circuit contact varistor connected to some current transformer loads.
According to the purpose of the use of varistor can be divided into two categories: ① protection with varistor, ② circuit function with varistor.
Protection resistance
(1) distinguish between power supply protection varistors, or signal lines, data line protection with varistors, they have to meet the requirements of different technical standards.
(2) Depending on the continuous operating voltage applied to the varistor, the varistor across the power supply line can be divided into two types of AC or DC, and the varistor is aged under these two kinds of voltage stresses Features are different.
(3) According to the varistor to withstand the abnormal over-voltage characteristics of different varistors can be divided into surge suppression, high power and high energy type of these three types.
★ Surge suppression type: refers to the suppression of lightning overvoltage and over-voltage and other transient over-voltage varistor, the emergence of this transient over-voltage is random, non-periodic, the current peak voltage may Very big. Most varistors all fall into this category.
★ high power type: refers to the absorption cycle for the emergence of continuous pulse group varistor, such as in the switching power supply transformer on the varistor, where the impact voltage cycle occurs, and the cycle can be seen, the energy value can generally Calculated, the peak voltage is not large, but the frequency is high, the average power is quite large.
★ high-energy type: refers to the absorption of generator excitation coil, lifting solenoid coil and other large inductor coil in the magnetic energy of the voltage transformer, for such applications, the main technical indicators of energy absorption capacity. Varistor protection, the vast majority of applications, it can be repeated many times, but sometimes it made it as a current fuse as a "one-time" protection device. Such as a short-circuit contact varistor connected to some current transformer loads.
