The word thermistor is a compound word derived from “thermo” (meaning heat) and resistor. It is actually a combination of heat and resistor, as its resistance vary directly or inversely to the temperature.
- Thermistor actually means thermal resistor.
So, there are basically two types of thermistors, which are:
- NTC and
- NTC means Negative Temperature Co-efficient, and its resistance varies inversely proportional to the applied temperature.
- PTC on the other Hand is Positive Temperature Co-efficient as its resistance varies directly proportional to the applied temperature.
Thermistors when connected in series with a resistor gives a corresponding change in voltage whenever the temperature is changed. This could be used to monitor the temperature of the thermistor surrounding by merely measuring the voltage across the thermistor.