Abstract: A passive keyless entry system that is specifically adapted for use with automotive vehicles is designed to automatically unlock the vehicle as the operator approaches the vehicle. The system is further designed to automatically lock the vehicle as the operator, carrying the beacon, moves away from the vehicle. The system includes a portable beacon that is carried by the operator, a receiver/controller located in the vehicle, and an antenna connected to the receiver/controller for receiving the encoded transmission from the beacon. The beacon includes a motion sensor to conserve battery life when the beacon is stationary. Transmission between the beacon and the receiver/controller is characterized by a magnetically coupled radio frequency signal embodying differential phase encoded data with error correction coding of the data to enhance noise immunity and signal discrimination.

Abstract: A passive keyless entry system is disclosed that is specifically adapted for use with automotive vehicles. The system is designed to automatically unlock the vehicle as the operator approaches the vehicle. The system is further designed to automatically lock the vehicle as the operator, carrying the beacon, moves away from the vehicle. The system includes a portable beacon that is carried by the operator, a receiver/controller located in the vehicle, and an antenna connected to the receiver/controller for receiving the encoded transmission from the beacon. The beacon includes a motion sensor to conserve battery life when the beacon is stationary. Transmission between the beacon and the receiver/controller is characterized by a magnetically coupled radio frequency signal embodying differential phase encoded data with error correction coding of the data to enhance noise immunity and signal discrimination.

Abstract: A passive keyless entry system is disclosed that is specifically adapted for use with automotive vehicles. The system is designed to automatically unlock the vehicle as the operator approaches the vehicle. The system is further designed to automatically lock the vehicle as the operator, carrying the beacon, moves away from the vehicle. The system includes a portable beacon that is carried by the operator, a receiver/controller located in the vehicle, and an antenna connected to the receiver/controller for receiving the encoded transmission from the beacon. The beacon includes a motion sensor to conserve battery life when the beacon is stationary. Transmission between the beacon and the receiver/controller is characterized by a magnetically coupled radio frequency signal embodying differential phase encoded data with error correction coding of the data to enhance noise immunity and signal discrimination.

Abstract: The present invention discloses apparatus and method for centering the steering wheel of a vehicle prior to alignment of the vehicle wheels using a wheel aligner. A portion of the apparatus is mounted to the vehicle steering wheel for sensing deviation in the position of the steering wheel from a centered position. This portion of the apparatus can be mounted on vehicle steering wheels having different configurations and can wirelessly transmit signals corresponding to the deviations. The apparatus can be used with differently configured steering wheels by virtue of a linked cam assembly in which rotation of either of a pair of cams causes rotation of the other cam in an opposite direction of equal magnitude. In operation, the deviation in the position of the steering wheel from a centered position with a pre-selected tolerance is determined. When the deviation is greater than the pre-selected tolerance, alignment of the vehicle wheels by the wheel aligner is prevented.

Abstract: The attenuation of RF pulses passing through a mineral slurry is determined by measuring the amplitude of the envelope produced by a series of successively occurring attenuated electrical pulses. The pulses are applied to the input of a variable gain amplifier, the gain of which is under control of a digital processor. The peak amplitude of each pulse is compared with a fixed reference voltage. The contents of a storage register associated with the processor is modified dependent upon whether the pulse amplitude is geater or less than the reference voltage. The contents of the register is used to control the gain of the variable gain amplifier in such a way that the amplitude of the next successive pulse will approach the value of the reference voltage. After the last pulse has been measured, the gain of the amplifier is inversely proportional to the amplitude of the pulse envelope, and the contents of the successive approximation register will also be proportional to the amplitude of the pulse envelope.