Small Temperature Coefficient Of Resistance 25D 431 Metal Oxide Varistor Non-Polarity

The main characteristics of varistors are wide operating voltage range (6~3000V, divided into several grades), fast response to overvoltage pulses (nanosecond level), strong impact current resistance (100~2000a), and small leakage current (micro An level), small temperature coefficient of resistance, high performance, low price, small size. It is an ideal protection component, which can form overvoltage protection circuit, muffler circuit, spark suppression circuit, and absorption circuit. When the overvoltage pulse is superimposed on the power network, after connecting the rheostat, the overvoltage peak waveform is flattened and limited within a certain range. When using inductance and capacitance to open or close the load circuit, the switch tip pulse appears in the DC waveform, and the varistor can absorb the counter electromotive force in the circuit, thus effectively protecting the switch circuit from damage

SPD varistor manufacturers believe that varistors have strong electrical characteristics and are a very mature electronic component that can be used in various electronic equipment to protect the claws, reduce lightning damage, and help improve the stability of the equipment It can be applied to lightning protection and automotive electrical and ignition systems. The resistance material of the varistor is a semiconductor, so it is a kind of semiconductor resistance. At present, a large number of 'zinc oxide' (ZnO) varistors are used, and their main materials are composed of a divalent element (Zn) and a hexavalent element oxygen (O). Therefore, from the material point of view, the zinc oxide varistor is a "II-VI oxide semiconductor".

When the voltage applied to the varistor is lower than its threshold, the current flowing through it is extremely small, which is equivalent to a resistor with infinite resistance. That is, when the voltage applied to it is below its threshold, it acts as an off-state switch. When the voltage applied to the varistor exceeds its threshold, the current flowing through it surges, which is equivalent to a resistor with infinitesimal resistance. That is, when the voltage applied to it is higher than its threshold, it acts as a closed switch.

Production Process / Quality Control​

Application

1. Varistor voltage: refers to the voltage value across the varistor at a specified temperature and DC (generally 1mA or 0.1mA). Recorded as V1mA or V0.1mAo
2. Maximum continuous voltage: refers to the maximum effective value of sinusoidal AC voltage or the maximum DC voltage value that can be continuously applied to both ends of the varistor for a long time under the specified ambient temperature
3. Limiting voltage: refers to the maximum peak voltage at both ends of the varistor when a specified surge current (8,20μs) passes through it.
4. Rated power: refers to the maximum average impact power that can be applied to the varistor under the specified ambient temperature.
5. Maximum energy: the maximum impact energy that can be applied to the varistor under the condition that the varistor voltage does not change more than ±10% and the impulse current waveform is 10, 1000μs or 2ms.
6. Current capacity (maximum inrush current)