Abstract: A motion detecting system including a plurality of transmitter housings. A plurality of motion detector transmitter mechanisms are situated in each of the transmitter housings. Each motion detector transmitter mechanism includes a motion detector adapted to emit a motion signal upon the detection of motion, a transmitter adapted to emit a transmitter activation signal via free space upon the transmission of the motion signal and only during the receipt of power, and a one-shot multivibrator mechanism connected to the motion detector and the transmitter. The one-shot multivibrator mechanism is adapted to transmit power for a predetermined amount of time upon the receipt of the motion signal. Further provided is a receiver unit including a housing and a receiver mechanism. The receiver mechanism includes a receiver adapted to accept the transmitter activation signal via free space.