A varistor (MOV) and a thermistor (NTC) are both types of electronic components that exhibit varying electrical properties based on changes in their surrounding environment. However, they serve different purposes and have distinct characteristics. Here's an overview of the differences between a varistor and a thermistor:
Function:
Varistor (MOV): A varistor, short for "variable resistor," is primarily used for transient voltage suppression and surge protection. It is designed to protect electronic circuits from voltage spikes by rapidly changing its resistance in response to voltage fluctuations.
Thermistor (NTC): A thermistor, derived from "thermal resistor," is primarily used for temperature sensing and temperature compensation. It changes its resistance in response to changes in temperature, allowing it to measure or regulate temperature in various applications.
Electrical Properties:
Varistor: A varistor is a non-linear resistor with a voltage-dependent resistance characteristic. It exhibits a very high resistance at low voltages but rapidly decreases its resistance when the voltage exceeds a certain threshold. This property makes it effective in diverting excessive voltage and protecting sensitive components.
Thermistor: A thermistor is a type of resistor that exhibits a change in resistance with temperature. It can be classified as either a positive temperature coefficient (PTC) thermistor or a negative temperature coefficient (NTC) thermistor. PTC thermistors increase their resistance with increasing temperature, while NTC thermistors decrease their resistance with increasing temperature.
Applications:
Varistor: Varistors are commonly used in electronic devices, power distribution systems, and electrical equipment to protect against voltage surges caused by lightning, power line transients, or other electrical disturbances. They provide overvoltage protection by shunting excess voltage to ground.
Thermistor: Thermistors are widely used in various applications related to temperature sensing and compensation. They can be found in thermostats, temperature controllers, temperature measurement devices, and temperature-compensating circuits in electronic systems.
Construction:
Varistor: Varistors are typically made of ceramic or metal oxide semiconductor materials. They consist of a bulk semiconductor material with two metal electrodes attached to it. The varistor's resistance is determined by the characteristics of the semiconductor material used.
Thermistor: Thermistors are generally composed of ceramic or polymer materials mixed with either metallic oxides or other conductive materials. They are typically available in bead or disc shapes and have two leads for electrical connections.
In summary, while both varistors and thermistors are electronic components that exhibit varying electrical properties, they have distinct functions and applications. Varistors are primarily used for transient voltage suppression and surge protection, while thermistors are mainly used for temperature sensing and compensation.
As manufacturer with 28+ years of experience in industry, UF Capacitors produce both varistor and thermistor. Feel free to send RFQ to inquiry@ufcapacitors.com for free qutote.