Circuit arrangement for a capacitive proximity switch

Abstract

Disclosed is a charge transfer-based circuit arrangement for capacitive proximity switches comprising a capacitive sensor element (C3), the capacity of which changes according to the actuation mode. The circuit arrangement includes a central capacitor (C2), a first controllable connecting means (D2) that impinges the capacitive sensor element with a charging voltage (U3) according to a triggering signal, and a second controllable connecting means (T1) which connects the capacitive sensor element to the central capacitor according to the triggering signal in order to transfer the charge from the capacitive sensor element to the central capacitor. The charging voltage can be an AC voltage while the connecting means can be impinged upon by the AC voltage in such a way that the first connecting means or the second connecting means is alternately conductive.

Dependencies are inferred from the claim text.