A thermistor is a type of temperature sensor that exhibits a change in resistance with variations in temperature. The name "thermistor" is a combination of "thermal" and "resistor." Unlike conventional temperature sensors that rely on voltage or current changes to measure temperature, a thermistor's resistance varies in response to changes in temperature.
Thermistors are typically made from semiconductor materials, and their resistance-temperature relationship can be either positive temperature coefficient (PTC) or negative temperature coefficient (NTC).
Negative Temperature Coefficient (NTC) thermistors: These are the most common type of thermistors. As the temperature increases, the resistance of an NTC thermistor decreases. Conversely, as the temperature decreases, the resistance increases. The relationship between resistance and temperature is nonlinear, meaning that the change in resistance is more pronounced at certain temperature ranges.
Positive Temperature Coefficient (PTC) thermistors: As the name suggests, PTC thermistors behave in the opposite way of NTC thermistors. Their resistance increases as the temperature rises and decreases as the temperature falls. This kind of thermistor is less common but finds applications in specific temperature-sensing scenarios.
Thermistors are widely used in various applications, including temperature monitoring and control in electronic devices, household appliances, automotive systems, industrial equipment, and medical devices. Their simplicity, reliability, and cost-effectiveness make them a popular choice for temperature sensing in a wide range of industries.