Thermistor is the kind of sensitive components, in accordance with the temperature coefficient can be divided into positive temperature coefficient Thermistors (PTC) and a negative temperature coefficient thermistor (NTC). Typical characteristic of thermal resistor is sensitive to temperature, show different resistance values at different temperatures. Positive temperature coefficient Thermistors (PTC) in high temperature resistance value, the more negative temperature coefficient thermistor (NTC) lower at the higher temperature resistance value, that they belong to semiconductor devices.