Patent ID: 8471164

Claim:
A capacitive switch ( 1 ), comprising a housing frame ( 2 ) by means of which a thin-walled cover plate ( 3 ) is held, a printed circuit board ( 4 ) with a copper layer ( 6 ) that generates a capacitive field ( 7 ) applied to a surface ( 5 ) of the printed circuit board ( 4 ) that faces the cover plate ( 3 ), with the copper layer ( 6 ) connected to an inside surface ( 8 ) of the cover plate ( 3 ), wherein at least two sensor surfaces ( 17 , 17 ′, 18 , 18 ′) are installed in the printed circuit board ( 4 ), the surfaces ( 17 , 17 ′, 18 , 18 ′) each being electrically connected via an integrated circuit ( 11 , 12 ) to a microcontroller ( 13 ) as the control and evaluation unit, and the printed circuit board ( 4 ) functions as an insulation between the copper layer ( 6 ) and the sensor surfaces ( 17 , 17 ′, 18 , 18 ′), and both integrated circuits ( 11 , 12 , 11 ′, 12 ′) are controlled alternately by the microcontroller ( 13 ) for measuring the capacitive field ( 7 ) of the copper layer ( 6 ).