The rated power of the thermistor is the power dissipation allowed by the long-term continuous load of the thermistor under the specified technical conditions. In actual use shall not exceed the rated power. If the ambient temperature at which the thermistor operates exceeds 25 ° C, its load must be reduced accordingly. Thermistors are a class of sensitive components, which are divided into positive temperature coefficient thermistors (PTC) and negative temperature coefficient thermistors (NTC) according to different temperature coefficients. The typical characteristic of thermistors is that they are sensitive to temperature and show different resistance values at different temperatures. Positive temperature coefficient thermistor (PTC) has a higher resistance value when the temperature is higher, and negative temperature coefficient thermistor (NTC) has a lower resistance value when the temperature is higher, and they are both semiconductor devices.