As a relatively common electronic component, varistor is an accessory that engineers are familiar with in the usual circuit design process. In addition, there is another electronic component that we usually use, that is, thermistor. The thermistor and varistor have similar names, so are the functions of the two similar? What are the differences between them? Let us let the experts of Ruilongyuan Electronics explain the differences between them. Which ones?
Let's look at the thermistor first. The thermistor we usually use is divided according to the temperature coefficient. It is a temperature-sensitive element. In normal use, the thermistor is divided into a positive temperature thermistor and There are two types of negative temperature thermistors, but both of these resistors belong to semiconductor devices.
Next, let’s look at the definition and application of varistor. From the name, we can know its application characteristics without looking at the definition, that is, it is sensitive to voltage. It has typical non-linear volt-ampere characteristics. In the usual circuit design process, it is mainly used to clamp the voltage when the circuit is subjected to overvoltage and absorb excess current to protect sensitive devices. The resistor body material of the varistor is a 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 the two. First of all, the two symbols in the circuit design are different. The thermistor symbol is PTC, and the varistor symbol is VSR, which is the most obvious way to distinguish between the two in circuit design. Secondly, the package colors of the two are also different. The common thermistor has a black appearance, while the common package appearance of the varistor is blue. After mastering these two ways of distinguishing, I believe that the new engineers will not confuse the two in their future work.
