When we use electrical appliances, we will find that mobile phones, TVs, refrigerators, etc. will be hot after working for a long time, but when mobile phones and TVs are not working, the temperature gradually drops. Why is that? In fact, the temperature increase is related to electricity.
Electrical appliances must be connected to the power supply to work, and without power, electrical appliances cannot start working. Current and temperature are related, generally proportional to the relationship, in a certain voltage range, the greater the current, the higher the temperature. And the motor power is large, the greater the current required, the greater the current, the higher the temperature. However, the operating temperature range of the motor is limited, once the temperature range of the electrical appliance is easy to short circuit, the electrical short circuit will not only explode damage the electrical appliance, but also endanger the person.
Therefore, the electrical appliance needs to control the temperature when working, and when the temperature rises to a certain level, the temperature is controlled to drop down. Electronic components that make up electrical appliances Temperature-related electronic components - thermistors.
Thermistors are temperature-sensitive electronic components that exhibit different resistance values at different temperatures. Thermistors are composed of semiconductor materials and belong to semiconductor components.
Thermistors are divided into two categories according to the temperature coefficient: positive temperature coefficient thermistors, referred to as PTC thermistors, within a certain temperature range, the resistance value increases with the rise of temperature; Negative temperature coefficient thermistors, referred to as NTC thermistors, within a certain temperature range, the resistance decreases with the rise of temperature.
NTC thermistor can play the role of temperature monitoring and temperature control to ensure that the electrical appliance will not be short-circuited and burst due to excessive temperature when working, and can ensure that the battery cell works within the temperature range of the electrical appliance and actively stops working at abnormal temperature.
If the electrical appliance is working in a short circuit explosion, in addition to paying attention to the power supply voltage is too high, but also pay attention to whether the NTC thermistor is inferior or aging, inferior NTC thermistor can easily lead to electrical short-circuit explosion, and NTC thermistor aging, unstable performance will also lead to electrical short-circuit explosion, need to be replaced in time.