Capacitive proximity sensor arrangement for use in rolling mill, has coil that is connected in series or parallel to capacitor i.e. source-gate capacitor, between control port and output terminal of input transistor

摘要

The arrangement (10) has a sensor electrode (101) shielded by a shielding electrode (102) against earth. The sensor electrode is connected to an input of an amplifier (104). The shielding electrode is connected with an output of the amplifier. The amplifier has an input transistor e.g. bipolar transistor, with a control port that is connected with the sensor electrode, and a coil. The coil is connected in series or parallel to a capacitor i.e. source-gate capacitor, between the control port and an output terminal of the input transistor.