Thermistor or thermal resistor are thermal sensitive resistor. It means its resistance changes with temperature. This change in resistance character divides the Thermistor into two types, depending in the way it responds to the temperature.
- Positive Temperature Coefficient Thermistor. (PTC)
- Negative Temperature Coefficient Thermistor.(NTC)
In this type, resistance of resistance of the Thermistor increases with the increase in temperature. These Thermistors are usually made from Barium, Titanate.
In this type, resistance of Thermistor decreases with increase in temperature. Thermistor are semiconductor component that behave as a resistor with usually, negative temperature coefficient of resistance. In some cases, resistance of a Thermistor at room temperature may decrease to 5 percent for each one degree Celsius rise in temperature.