Patent ID: 8111075

Claim:
Electronic circuit for the detection of a capacitive variation, for use in household appliances characterized in that the electronic circuit is able to detect a differentiated capacitive variation on two distinct contact capacitors, (C 1 , C 2 ), and in that the electronic circuit comprises an apparatus that: squares, using squaring circuits, a signal generated by a common pulse generator and filtered by two parallel filters (R 1 , C 1 -R 2 , C 2 ) to generate two respective signals of squared pulse trains (TP 4 , TP 5 ), wherein respective capacitors (C 1 , C 2 ) in the two filters are the two distinct contact capacitors (C 1 , C 2 ), each of the two distinct contact capacitors being connected to a common ground (G), and compares said two signals of squared pulse trains (TP 4 , TP 5 ) with a comparator device comprising a logic gate, and provides a direct-current output signal (KEY) depending on the result of said signals comparison.