What are the application types of piezoresistors in circuits?

Varistor is a kind of voltage-limiting protection device. Using the nonlinear characteristics of varistor, when overvoltage appears between the two poles of varistor, varistor can clamp the voltage to a relatively fixed voltage value, thus realizing the protection of the subsequent circuit. The main parameters of varistor include varistor voltage, current capacity, junction capacitance, response time, etc.

It is very important to know the parameter types and applications of varistor.

The first category is the connection between power lines or between power lines and the earth. As a representative application occasion of varistor, it plays a protective role on electronic products when the power lines and long-distance transmission signal lines encounter lightning strikes and lead to surge pulses. Generally, connecting piezoresistors between lines can induce pulses between lines and connecting piezoresistors between lines and ground can induce pulses between transmission lines and ground. If the two forms of line-to-line connection and line-to-ground connection are further combined, the surge pulses can be better absorbed.

The second category is the connection in the load, which is mainly used to absorb the induced pulse caused by the sudden opening and closing of the inductive load, so as to prevent the components from being damaged. Generally, it only needs to be connected in parallel with the inductive load.

The third category is the connection between contacts, which is mainly to prevent the contact of the induced charge switch from being burnt out by electric arc. Generally, it is enough to connect the contact in parallel with the varistor.

The fourth category is mainly used for the protection connection of semiconductor devices, which is mainly used for semiconductor devices such as silicon controlled rectifier and high power triode. Generally, it is connected in parallel with the protection devices to restrict the voltage from being lower than the withstand voltage level of the protected devices, which plays a very good role in protecting the semiconductor devices.