Visit：6704次  Date：2022-09-22

As a common electronic component, varistor is a familiar accessory for engineers in the ordinary circuit design process. In addition, there is another kind of electronic component that we usually use, that is, thermistor. Thermistors and varistors have similar names. Do they have similar functions? What are the differences between them? Now let's explain the differences between them.

Let's start with thermistors. The thermistors we usually use are classified according to the temperature coefficient. They are temperature sensitive elements. In the normal use process, thermistors can be divided into positive temperature thermistors and negative temperature thermistors, but both of them belong to semiconductor devices.

Next, let's look at the definition and application of varistors. From the name, we can know its application characteristics without looking at the definition, that is, it is sensitive to voltage. It has typical nonlinear volt ampere characteristics, and is mainly used for voltage embedding when the circuit is under overvoltage to absorb excess current in order to protect sensitive devices. The resistance material of varistor is semiconductor, so it is also a variety of semiconductor resistors.

After understanding the definition and application range of varistors and thermistors, let's take a look at the actual differences between them. First of all, the symbols of the two are different in circuit design. The symbol of thermistor is PTC and the symbol of varistor is VSR, which is also the most obvious way to distinguish them in circuit design. Secondly, the package colors of the two are also different. Common thermistors are black, while common varistors are blue. After mastering these two ways of distinction, I believe that new engineers will not confuse the two in their future work.