Patent US 4,016,428

An automatic power switching circuit for controlling the application of electrical power to an electric typewriter or like apparatus. Radiated electrical energy emanating from alternating current machinery is transmitted to an input antenna by the touch of the operator. The input alternating current signal is shaped to produce electrical signal indicia responsive to the operator's contact with the apparatus. The input signal is transmitted to a timing circuit to initiate the time-out of predetermined delay following which an output signal will be generated and the apparatus will be disconnected from the power source in the absence of human contact during the delay interval.