Abstract: Fault protection using parallel output CMOS devices for integrated circuit analog switches prevents damage to circuits incorporating the same by not coupling analog input voltages beyond the power supply voltages to the analog output, and by preventing the forward biasing of any P/N junction to provide a low impedance path between such fault analog input voltage and either power supply terminal. Circuitry is provided for having the analog output electrically floating whenever the switch is commanded off, regardless of whether the analog input is within the power supply voltage range or not, to provide the analog input as the analog output whenever the switch is commanded on and the analog input is within the power supply voltage range, and to clamp the analog output at the closest power supply voltage whenever the switch is commanded on and the analog input is beyond the power supply voltage range. Alternate embodiments are disclosed.

Abstract: A motion detection apparatus indicates the presence of an object in a given area by sensing the change in electrostatic charge in the area caused by the disturbance of the electric field within the range of the apparatus. An antenna, which may take a number of different forms, is placed at a convenient location within the area to be monitored, and the output of the antenna is connected in a shielded manner to the input of a shielded high gain amplifier with a very high impedance-low leakage current input stage and which has a filter connected thereto having a cut off frequency of up to approximately 20Hz. Connected to the output of the amplifier is a circuit, which may include a power line frequency filter, which produces an output signal, for example, an alarm, whenever the amplitude of the output signal from the amplifier exceeds a predetermined value.