Abstract: A security system and method is provided for one way communication between a remote transmitter and a receiver which enables a function such unlocking the doors or disarming a security system. The system uses a three part security code having one part which is a pseudo-randomly generated function, one part which is a permanently assigned code to the transmitter/receiver combination and one part which is based on the number of transmissions transmitted by the transmitter.

Abstract: An automatic headlamp dimmer system for switching a vehicle's headlamps from high beam to low beam when lights from another vehicle are detected in front of the vehicle. To prevent spurious responses to reflected light from signs and other sources, the dimmer system includes a light detector which is responsive only to infrared light. Also, unwanted responses to flashing lights are avoided by detecting the presence of a periodically varying light signal, and inhibiting switching between high and low beams in response thereto. The system is also capable of sensing the activation of windshield wipers and preventing headlamp switching caused by interruption of light to the system's light sensor by action of the wiper blades.

Abstract: An automatic headlamp dimmer system for switching a vehicle's headlamps from high beam to low beam when lights from another vehicle are detected in front of the vehicle. To prevent spurious responses to reflected light from signs and other sources, the dimmer system includes a light detector which is responsive only to infrared light. Also, unwanted responses to flashing lights are avoided by detecting the presence of a periodically varying light signal, and inhibiting switching between high and low beams in response thereto. The system is also capable of sensing the activation of windshield wipers and preventing headlamp switching caused by interruption of light to the system's light sensor by action of the wiper blades.

Abstract: A control circuit for a reversible D.C. window drive motor that allows for one touch operations of the motor to automatically lower the associated window to its full down position following a relatively short actuation of the control switch in the "DOWN" position. Subsequent actuation and release of the control switch will cause interruption and inhibit the automatic lowering of the window. Longer actuations of the control switch allows for direct movement control of the window in the downward direction. Stall current sensing and excessive time sensing provide protection to the motor and the drive circuitry.