Kapazitive Sensoranordnung

摘要

The sensor has a charge balance frequency converter consisting of an operational amplifier (6) with an integrating capacitor connected between its output inverting input. A reference voltage is connected to its non-inverting input and its output. There is one capacitor (C1) with one terminal (2) connected either to a potential or the reference voltage and the other (5) either to the amplifier inverting input or the reference voltage. Another capacitor (C2) has one terminal connected either to the reference voltage or another voltage and the other terminal (13) connected to the reference voltage or the amplifier inverting input. The amplifier output is connected to a comparator (7) with a clock generator (3) to control the switching operations. The two voltages are equal and are provided by an auxiliary voltage (U), and the two capacitors form a differential capacitor.