Inductively Coupled Sensor/Actuator System for Closed-Loop Control Applications at High Temperatures and in Aggressive Environments

This paper presents a sensor/actuator system for high-temperature applications with the complete measurement electronics and sensors integrated into the actuator. The data transmission is implemented as point-to-point power line communication (PLC), between the sensor/actuator system and its control unit. A separable transformer serves as an inductively coupled contactless connector for both power and bidirectional PLC-data, allowing for a perfect hermetic seal. We discuss the increased requirements for the measurement electronics at high operating temperatures and we present a special ratiometric self-calibration technique to eliminate temperature drifts that is also suitable for integration into an application specific integrated circuit (ASIC).