Why does a varistor break down? What should I do after it breaks down?

In addition to capacitors, resistors are also very important in electronic products, such as varistors. Varistors are resistors with nonlinear volt-ampere characteristics, and their resistance materials are composed of semiconductor materials. Therefore, varistors belong to semiconductor components.

Varistors are generally connected between the two levels of a circuit power supply. When the voltage across the varistor is too large, the varistor clamps the voltage to control the circuit voltage within a reasonable range, absorbing excess current to prevent the circuit from burning out and protecting other components. Therefore, varistors are also called surge protectors.

Zhixu Electronic Varistor

When the voltage across the varistor is normal and there is no surge, the varistor is equivalent to an open circuit and the resistance is infinite. When the voltage across the varistor is slightly higher than the rated voltage, the resistance value of the varistor changes from a high-resistance state to a low-resistance state as a surge protector, and it quickly conducts and shunts in a short time, dividing the voltage to protect the subsequent circuits and components.

However, the rated voltage of the varistor is limited. When the voltage across the varistor far exceeds the rated voltage, the current flowing through the varistor is too large and generates heat, thereby breaking down the varistor. Such breakdown will damage the varistor and make it impossible to recover.

Zhixu Electronic Varistor

If the varistor is broken down and cannot be used, we can replace the varistor. To avoid the problem of breakdown in the future, you can choose a varistor with a high rated voltage when replacing the varistor. When choosing a varistor, you must choose a manufacturer with a good reputation, quality assurance, quality, and after-sales service guarantee. In this way, even if the varistor has after-sales problems, the manufacturer will help you solve them.