Varistor is a kind of nonlinear resistor, and its main materials are metal oxides (zinc oxide (ZnO), barium oxide (BaO), and other metal oxides). The resistance value of varistor will change with the change of applied voltage. When the voltage is lower than a certain threshold, its resistance is so high that it hardly works; When the voltage exceeds the threshold, the resistance drops sharply, thus conducting a large amount of current to protect the circuit. When encountering transient high voltage (such as lightning strike and power supply fluctuation), the varistor will conduct quickly, absorb and disperse excess energy, and prevent the circuit from being damaged. Widely used in power sockets, switching power supplies, household appliances, computers, televisions, industrial automation and control systems, to protect equipment from voltage spikes, help reduce voltage fluctuations and interference, and effectively absorb and disperse overvoltage.
