Circuit arrangement for a capacitive proximity switch
First Claim
1. A circuit arrangement for a capacitive proximity switch for the determination of an operating state and having:
- a capacitive sensor element, whose capacitance changes as a function of said operating state;
a central capacitor;
a first controllable connecting means which, as a function of a triggering signal, supplies a charging voltage to said capacitive sensor element; and
a second controllable connecting means, which, as a function of said triggering signal, connects said capacitive sensor element to said central capacitor for a transfer of charge from said capacitive sensor element to said central capacitor,wherein said charging voltage is an AC voltage supplied from an AC voltage source and said AC voltage is supplied to said connecting means as the triggering signal in such a way that, in alternating manner, said first connecting means or said second connecting means is conductive.
1 Assignment
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Accused Products
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.
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Citations
11 Claims
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1. A circuit arrangement for a capacitive proximity switch for the determination of an operating state and having:
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a capacitive sensor element, whose capacitance changes as a function of said operating state; a central capacitor; a first controllable connecting means which, as a function of a triggering signal, supplies a charging voltage to said capacitive sensor element; and a second controllable connecting means, which, as a function of said triggering signal, connects said capacitive sensor element to said central capacitor for a transfer of charge from said capacitive sensor element to said central capacitor, wherein said charging voltage is an AC voltage supplied from an AC voltage source and said AC voltage is supplied to said connecting means as the triggering signal in such a way that, in alternating manner, said first connecting means or said second connecting means is conductive. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification