| 摘要 |
A capacitive switch (1) comprising a housing frame (2), a thin-walled cover plate (3) held thereon, a printed circuit board (4) with a copper layer (6) that generates a capacitive field (7) applied to a surface (5) of the circuit board (4) that faces the cover plate (3), the copper layer (6) being connected to an inside surface (8) of the cover plate (3), the capacitive switch (1) being adapted to ensure that electrical devices can be operated safely, in that changes in the capacitive field (7) are picked up by the switch (1) in a redundant manner. At least two sensor surfaces (17, 17', 18, 18') are disposed in the circuit board (4), and are each electrically connected via an integrated circuit (11, 12) to a microcontroller control and evaluation unit, and the 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).
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