Circuit and method for evaluating measurement signals and sensor system for capacitively detecting obstacles

• Main Authors: Kelsch, Manuel, Wiest, Thomas
• Format: Patent
• Language: English
• Published: 02.04.2019
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; PULSE TECHNIQUE; TARIFF METERING APPARATUS; TESTING

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.