Application of NTC thermistor in Automobile Water Temperature Sensor
The vehicle water temperature sensor is an important sensor used to measure and control the temperature of the engine.It can be divided into two categories, but in either case, its internal structure is NTC thermistor.
This water temperature sensor resists between 275 ohm and 6500 ohm. And the resistance changes as the temperature changes, and the resistance gets smaller and smaller as the temperature increases.
In the first category, the function of water temperature sensor is relatively simple.
It is to drive the change of water temperature meter through the change of the internal resistance of the sensor and the change of the cooperative current., indirectly telling people the working temperature of the automobile engine.
This water temperature sensor has low accuracy requirement for NTC thermistor, but it has high voltage resistance to NTC thermistor.
In the second category, the water temperature sensor is structurally unchanged, and its function is to provide an analog signal of temperature change to the engine control unit.The main function is to tell people what the temperature of the engine control unit is now.
In turn, the signal of this water temperature sensor is important to the control unit.The main reason is that the engine has different working methods at different working temperatures.
It has high requirement for NTC thermistor. High accuracy, high reliabilty, high sensitivity NTC thermistor will be the best choice.
The main difference between the two temperature sensors is that they need to operate under different voltage conditions.
The voltage of the temperature sensor for the water temperature meter is 12V, and the voltage of the temperature sensor for the engine control unit is 5V, so they are not interchangeable.
Users need to select different water temperature sensor in different situations.