A circuit arrangement (11) has an activating circuit (13) for a sensor element (12) of a touch contact switch, which in one embodiment of the invention contains a frequency generator (16). The frequency generator (16) generates a frequency-modulated activating signal (17), which is applied to the sensor...http://www.google.fr/patents/US5973417?utm_source=gb-gplus-shareBrevet US5973417 - Circuit arrangement for a sensor element
