Abstract: An electronic compass for use in a vehicle includes compensation for attaining a high degree of accuracy without operator intervention or the need to drive the vehicle in a deliberate circular path. An automatic method for accurately determining maximum and minimum voltage values from a flux gate sensor having orthogonal sensing windings is provided that operates continuously to adjust for required changes in both the offset and gain compensation factors. The flux gate sensor is further mounted within the vehicle such that the axis of one of the sensing windings is positioned approximately 45.degree. with respect to the vehicle's longitudinal direction. The angled mounting of the sense winding axis results in strong sensing signals when travelling on most roads. The electronic compass further provides visual representation on the outer peripheral segments of an alphanumeric display to prompt the operator to drive in a circle during a manual compensation mode.

Abstract: An electronic display device for presenting directional information to the operator of a motor vehicle. The display simultaneously shows current vehicle direction of travel as well as the relative directions of the 4 major compass axes by converting the direction information from an electronic flux gate compass. The device is further optimized to reduce the number of pin connections to the display and associated driver complexity and is readily applicable to LED, LCD or vacuum fluorescent type display elements.

Abstract: A device for automatically disengaging an automotive cruise control system whenever one or more failures or malfunctions occur in the vehicle brake system and also if such a malfunction should occur when the vehicle is in the "resume speed" mode of the cruise control system. The device comprises an exclusive NOR circuit whose two symmetrical input terminals are connected to opposite sides of the brake switch in series with the vehicle power source. The output from the exclusive NOR circuit is connected to a logic control circuit and through a control resistor to a vehicle power lead. Any malfunction of the brake circuit when the cruise control is in operation will cause the exclusive NOR output to go from a relatively low to a relatively high potential thereby causing a logic control circuit to provide a disconnect signal to a throttle actuator. An additional safety factor is attained by connecting the control resistor to the base of a transistor in a power lead to the throttle actuator.

Abstract: For use on an automotive vehicle equipped with an internal combustion engine and an automatic speed control system, a device for detecting accidental engine load removal and for providing disengagement of the speed control system to prevent an engine runaway condition. The device comprises a circuit that compares present engine speed with a previous engine speed furnished after a time delay to produce an output signal when a preselected engine speed differential occurs during the delay period. The output signal is utilized to disengage the speed control system directly or alternatively, to turn off the engine ignition system.

Abstract: A compact fluid flow sensor of the variable area type is disclosed which can accurately measure a broad range of flow rates and can be installed in any position relative to the horizontal plane and which is therefore particularly adaptable for use with vehicular fuel systems. The sensor comprises connected input and output housing members that retain between them a flexible diaphragm having an annular central orifice member. An adjustable needle valve is positioned within the orifice member to form a small, variable opening for fluid. The orifice member is connected to a core member of a differential transformer whose windings are connected to a circuit producing output signal responsive to the linear position of the core member. The varying pressure differential due to fluid flow rate created on opposite sides of the diaphragm causes the orifice member, and its attached core member, to move relative to the windings and produce an output from the differential transformer proportional to the fluid flow rate.

Abstract: A system is disclosed for automatically controlling the shutdown and restarting of a vehicle engine in order to conserve fuel at times when the vehicle would be otherwise stopped, with the engine running at idle speed and including in combination, an accumulator for computing and displaying the amount of fuel saved during shutdown. A central control comprised of an auto shutdown logic section and an auto start time delay logic section is connected to signal producing components on the vehicle and its engine and provides outputs to control engine shutdown and restart. The accumulating device utilizes an idle fuel flow reference with a clock input to compute the amount of fuel saved, which is indicated on the attached display. The logic functions of the accumulator are accomplished by a programmed microprocessor.