With a bang, the electric fan exploded. Have you ever had such an experience? This is because the voltage is too high, but it does not rule out that the electric fan has been used for too long.

The upper limit of voltage that the human body can accept is 36V, and the voltage that electronic products can accept will not exceed 220V, which is also the voltage of our household electricity. So what impact will high voltage have?

High voltage will cause harm to human body and electronic products. The circuit voltage is too high, the electronic product performance is unstable, easy to leak electricity, not only electronic products are easy to age and damage, the use time is greatly reduced, but also easy to harm personal safety; and high voltage leads to excessive power of electronic products, body heat, there is a great possibility of burning electrical appliances caused by fire, in order to solve the circuit voltage is too high, protect electronic products and personal safety, people invented protective electronic components, varistor is one of them.

Varistor is based on zinc oxide, mixed with Bi2O3, Co2O3, MnCO3 and other metal oxides, made of resistors through multiple processes, belonging to semiconductor resistors, its resistance value is sensitive to voltage, resistance value changes with voltage changes, is one of the protective electronic components on the circuit, in the circuit is an important existence.

Generally varistor is used in conjunction with fuse in the circuit for voltage protection or lightning protection. When the circuit voltage is too high, varistor can withstand overvoltage and perform voltage clamping, absorb excess current in the circuit, protect the circuit and the electronic components behind it, and prevent excessive current from causing damage to other electronic components.

If there is abnormal high voltage in the circuit, exceeding the range that varistor can withstand, it may cause varistor damage. Varistor damage can not be replaced by any varistor or electronic components at will. It must be replaced by the same type of varistor. Otherwise, it will not only fail to achieve the effect of limiting pressure protection, but also accelerate the damage of electronic products.

This is also why varistor has many different models. When choosing varistor, choose according to the previous varistor model.