Although there is only one word difference between thermistor and varistor, they are different. Today, combining with practical application, I will introduce the difference between thermistor and varistor.
First, the difference in sensitivity
(1) Thermistors are temperature-sensitive protection components, which are generally divided into positive temperature coefficient thermistors (PTC) and negative temperature coefficient (NTC), and their resistance values are different according to different temperatures;
(2) Varistors are resistance components which are sensitive to voltage and have nonlinear volt-ampere characteristics. In the range of voltage-sensitive voltage, when overvoltage occurs, it can effectively suppress large current and achieve the purpose of protecting circuit;
Second, the material difference
(1) Most thermistors are made of semiconductor materials;
(2) Metal oxides, such as zinc oxide, are commonly used in piezoresistors;
Third, the difference between circuit connections
(1) Thermistors are usually connected in series in a circuit, and the resistance value is equivalent to zero, which is similar to the function of a fuse;
(2) The varistor is connected in parallel in the circuit, and the resistance value will change with the change of voltage;
Fourth, the difference in appearance
(1) The thermistor usually appears as a black figure;
(2) Most piezoresistors are blue, and their surface printing varies with the model.
Conclusion: The use of thermistor can effectively restrain the starting surge current, and after the function of restraining surge current is completed, it is the simplest and most effective measure to ensure the electronic equipment from being damaged by the continuous function of current. A varistor is like a voltage-controlled switch, which will be short-circuited when the voltage reaches the breakdown voltage of the varistor. Under normal circumstances, piezoresistors and thermistors will be used together. When the voltage suddenly rises, the varistor breaks through the circuit current and rises rapidly. The thermistor generates heat, the internal resistance is too large, and the current decreases. This will protect against overvoltage and overcurrent.
The above content mainly introduces the difference between thermistor and varistor. If you need thermistor and varistor related products, please leave a message or call: 0755-28100016; Massive thermistors and piezoresistors are in stock with complete specifications. Welcome to inquire about the price or take samples for testing.
Shenzhen Shunhai Technology Co., Ltd. is an integrated supplier of electronic components, semiconductor devices and protection devices, Mainly engaged in TVS transient suppression diode, ESD electrostatic protector, GDT ceramic gas discharge tube, TSS semiconductor discharge tube, NTC thermistor, varistor, fuse, alloy resistor, chip resistor, precision resistor, wafer resistor, chip fuse, self-recovery fuse, chip capacitor, tantalum capacitor, electrolytic capacitor, aluminum electrolytic capacitor, supercapacitor, connector and other related product lines. Brands can be elected from Huade, Shuokai, Saruiwei, Yineng, Tesscara, KEMET, Tianer, Wangquan, Dayi, Murata, Taiyi, TDK, AVX, Weishi, Fenghua, Huaxin Branch, Sanying, Guoju, Lilong, Housheng, Guangluo, Shunluo, etc.
