Abstract: A keyed lock in which a key transmits programmed high frequency pulses which are capacitively coupled to an electronic lock which processes and decodes the high frequency pulses and provides an unlocking signal when the programmed pulses match a preset lock program.

Abstract: A motion alarm system including a motion detector which provides a motion signal. A signal level detector for detecting the motion signal and providing an output signal when the motion signal exceeds a selected level, and an alarm circuit providing an alarm if the motion signal does not exceed the selected level for a predetermined time.

Abstract: A motion sensing system which can be oriented in any position and which provides an output signal when it is moved or tilted. The system includes an oscillator which provides an output signal; the amplitude of the oscillator signal is modulated responsive to motion. A signal level detector provides an output signal when the modulation amplitude exceeds a predetermined level. The output signal from the level detector indicates excessive motion and can be used to provide an alarm or to control associated equipment.

Abstract: An antitheft system for vehicles in which an operator actuates a thumbwheel to select one predetermined numerical combination and actuates a push button switch to turn on the system. The operator also actuates the thumbwheel to select another predetermined numerical combination and actuates the push button switch to turn off the system. The actuation of the thumbwheel by an operator to a numerical combination other than one of the predetermined numerical combination results in the operation of an alarm. Disposed within the vehicle are mercury switches, which sense any movement of the vehicle, when the system is turned on. When a mercury switch senses any movement of the vehicle, such as movement caused by the towing of the vehicle or the jacking up of the vehicle, the change of state of the mercury switch initiates the operation of an alarm. Also, the opening of a hood, door or trunk will initiate the operation of an alarm when the system is turned on.