NTC temperature sensor application example
July 30, 2021
NTC temperature sensor
NTC temperature sensor is a kind of thermistor and probe, its principle is: the resistance value drops rapidly as the temperature rises. It is usually composed of 2 or 3 metal oxides, mixed in fluid-like clay, and calcined in a high-temperature furnace to form dense sintered ceramics. The international dimensions are very flexible, they can be as small as .010 inches or very small diameters. There is almost no limit to the maximum size, but it is usually suitable for less than half an inch.
NTC temperature sensor has the advantages of accurate temperature measurement, high sensitivity and good stability. It is widely used in the fields of temperature detection and temperature compensation. With the popularization of artificial intelligence and the vigorous development of new energy vehicles, the market prospect of NTC is very impressive.
1. Application of NTC temperature sensor in home appliances
In our daily life, in fact, there is more or less connection with the temperature sensor all the time. It can be said that life is completely inseparable from the NTC temperature sensor. Basically all large and small home appliances that involve temperature control will be applied to NTC temperature sensors. For example, the most commonly used smart rice cookers, microwave ovens, washing machines, air conditioners, refrigerators and so on.
NTC temperature sensor in smart rice cooker:
The highest heating temperature of commonly used electric rice cookers is generally controlled at 103°C, and the heat preservation temperature is controlled at 65°C. There is a temperature control device inside.
It is mainly composed of a heating plate, a temperature limiter, a heat preservation switch, a lever switch, a current-limiting resistor, an indicator light, a socket, etc. Its temperature control is divided into two processes. When cooking rice, it is first heated to 103℃ to cook the rice After the power is turned off, use the electric hot plate to preheat the simmered rice, and then keep it at 65-70°C.
The temperature control of the rice cooker is through the metal sheet detection circuit. The metal sheet is made of two kinds of metal sheets with different expansions. They are installed on the heating plate to feel the temperature of the heating plate. The heating temperature is heated by the heating plate. The heating plate is equipped with a temperature control element temperature sensor. Through the control of the temperature sensor, it is specially pointed out why the temperature sensor is used to control the temperature. The boiling point of the water in the rice cooker is under the standard atmospheric pressure when cooking rice. When the rice cooker is used to cook rice and the top cover is closed, a relatively sealed space is formed in the rice cooker. During the heating process, as the water vaporizes, the air pressure in the rice cooker will change. When the temperature rises, the boiling point of the water rises. The rice cooker is not equipped with a temperature sensor element to control the temperature, which may easily cause the rice cooker to explode and cause danger. The function of the NTC temperature sensor is that when the temperature rises to a certain temperature, it will break due to expansion and deformation. When the power is turned on, when the temperature drops, the metal sheet will return to its original state and continue to be energized. The characteristics of the temperature sensor are very suitable for the temperature control of the rice cooker.