Presence, position or proximity detecting circuit, e.g. for motor vehicle door locking system, has generator which supplies resonant frequency to electrode device and LC network

摘要

The circuit includes a sensor electrode arrangement with an electrode device forming part of a capacitor system whose capacitance with respect to a reference potential is dependent on the presence, position or proximity of objects in an observation range. The sensor electrode arrangement is coupled to an evaluation circuit. An LC network is coupled to the capacitor system. A generator supplies a frequency in the range of a parallel resonant frequency of the LC network to a system including the electrode device and the LC network. An independent claim is included for a method of detecting the presence of an object.