Abstract: An electronic switch which has no moving parts and is actuated by the capacitance of an operator providing a connection between earth ground and an input to the electronics associated with the switch is disclosed. The electronic switch in the preferred embodiment, includes a plate accessible to the tough of a human operator electrically connected to a first amplifier, and particularly to the input which is isolated from and thus oscillating with respect to earth ground. The output of the first amplifier is simultaneously connected to one end of a storage capacitor, having its other end connected to earth ground, and to one end of a high impedance. A second amplifier, is connected to the other end of the high impedance to provide a switched output, with the switched output having a first state for approximating an electrical short circuit and a second state for approximating an electrical open circuit.

Abstract: A touch actuated electronic switch is disclosed including at least one surface, accessible to the touch of a human, interconnected with an active circuit and protected against static electricity. In the preferred embodiment, the active circuit is differential sensing circuitry, preferably, dual input logic circuitry, and most requiring protection from static electricity at this time, a MOS exclusive OR gate. In the preferred embodiment where the interconnection between the logic circuit and the surfaces is desired to include long wires, a twisted pair of wires is used if increased noise immunity or noise protection is desired. The twisted pair is interconnected at one end with one wire electrically connected to the touch surface and the other substantially equal length wire being unconnected or connected to a second touch surface. Both wires are connected at their other ends to the dual inputs to the logic circuitry.

Abstract: A touch actuated electronic switch is disclosed including a surface, accessible to the touch of a human, interconnected with a differential amplifier. In the preferred embodiment, if increased noise immunity or noise protection is desired, a twisted pair of wires is used and interconnected at one end with one wire electrically connected to the touch surface and the other substantially equal length wire being unconnected. Both wires, at the other end, are connected to the input to the differential amplifier. A common mode alternating voltage signal is then provided to the differential amplifier and a substantial alternating frequency output signal shunt is applied to the differential amplifier, in the preferred embodiment, across terminals conventionally used for D.C. offset null purposes. The output of the differential amplifier is then interconnected to an integrator, in the preferred embodiment a capacitor, and the integrator is in turn connected to an additional amplifier.