Abstract: A circuit for evaluating measurement signals of at least one sensor with a control circuit. A control signal having a first frequency is generated by a control section of the control circuit, and the control signal is applied to the sensor. An electronic evaluation unit is provided for generating an evaluation signal originating from a measurement signal generated by the sensor. The electronic evaluation unit generates an opposing signal having the first frequency and a modifiable phase angle and superposes the opposing signal and the evaluation signal. The signal resulting from the superposition of the opposing signal and the evaluation signal is fed to a synchronous demodulator of the electronic evaluation unit.

Abstract: A circuit for evaluating measurement signals of at least one sensor with a control circuit. A control signal having a first frequency is generated by a control section of the control circuit and the control signal is applied to the sensor. An electronic evaluation unit is provided for generating an evaluation signal originating from a measurement signal generated by the sensor. The electronic evaluation unit generates an opposing signal having the first frequency and a modifiable phase angle and superposes the opposing signal and the evaluation signal. The signal resulting from the superposition of the opposing signal and the evaluation signal is fed to a synchronous demodulator of the electronic evaluation unit.

Abstract: A sensor system for the capacitive detection of obstacles, having a capacitive sensor with conductive elements and a control circuit connected thereto. The control circuit has a bridge circuit, and a first end of the bridge branch is connected to a conductive element of the sensor positioned upstream in the direction of detection and a second end of the bridge branch is connected to a conductive element of the sensor positioned downstream in the direction of detection. A control signal is generated by a control section of the control circuit and the sum of impedances of the bridge circuit connected to the first end of the bridge branch is less than the sum of impedances of the bridge circuit connected to the second end of the bridge branch. An electronic evaluation unit is provided to evaluate a voltage difference between the first and second ends of the bridge branch.