What is an automotive seat heating sensor?
The automotive seat heating sensor is a crucial safety and control component in the seat heating system. It is usually a negative temperature coefficient thermistor, whose main function is to monitor the temperature of the seat surface in real time and feed back the signal to the control module to prevent the seat from overheating and achieve constant temperature control.
In simple terms, it is like the “thermometer” and “safety officer” of the seat heating system.
2. Main Function
1. Temperature feedback and control: The sensor transmits the detected temperature signal to the control unit (ECU). The ECU, based on this signal and the user-set temperature level, dynamically adjusts the power of the heating wire (usually through PWM pulse width modulation) to stabilize the seat temperature at the set value.
2. Prevention of overheating and safety guarantee: This is its most important safety feature. If the sensor detects an abnormal increase in temperature (for example, due to localized compression causing heat accumulation, or system failure), the ECU will immediately cut off or reduce the heating power to prevent passengers from getting burned or causing a fire. This is a standard safety configuration for all modern seat heating systems.
3. Enhancement of comfort: Through precise temperature control, it avoids the seat becoming excessively hot after prolonged heating, maintaining a comfortable and constant temperature.
3. Working Principle and System Workflow
The seat heating system is a typical closed-loop control system.
Components:
Heating wire: Heating source, embedded in the seat cover.
Temperature sensor: Measures temperature.
Control switch/ECU: User input and control center.
Cable: Connects all components.
Work Flow:
1. The user sets the desired temperature level (such as high, medium, or low) through the switch.
2. The ECU powers on and provides full power to the heating wire, causing the seat to rapidly heat up.
3. The temperature sensor continuously monitors the surface temperature of the seat and sends real-time signals of resistance value changes (corresponding to temperature changes) to the ECU.
4. The ECU compares the received temperature signal with the preset target temperature.
5. When the temperature approaches or reaches the target value, the ECU begins to reduce the power supplied to the heating wire (for example, from continuous power supply to intermittent power supply), entering the “thermodynamic preservation” state.
6. If the sensor detects that the temperature exceeds the safety threshold (such as 45°C – 50°C), the ECU will immediately cut off the power supply to achieve overheat protection.
7. Throughout the process, the system continuously adjusts the power output based on the feedback from the sensor to maintain a constant temperature.
Post time: Nov-13-2025