Abstract: An electronic module includes a Printed Circuit Board (PCB) which contains a plurality of circuit elements. The electronic module is electrically connected to other electrical components in a vehicle by a connector. The PCB is contained within an electrically conductive housing which includes a box and a cover. A ground trace printed on the PCB extends to a mounting hole in the PCB and provides a ground path for the circuit elements. An electrically conductive metal ferrule which elevates the PCB above the box and the cover above the PCB, extends through the mounting hole in the PCB and contacts the cover and box when the cover is fitted onto the box. A mounting bolt extends through the cover inside the ferrule through the box and into a nut mounted into a metal portion of the vehicle.

Abstract: A variable force solenoid for operating a hydraulic pressure regulating valve which includes an actuator shaft aligned with the central axis of the valve and solenoid, a coil of electrical conducting wire, a cylindrical core on which the wire is wound and through which the induced magnetic flux flows, an actuator actuates shaft spaced by a non-working air gap from the casing and moveable axially toward and away from the edge of the core, flexible bearings at opposite axial ends of the actuator shaft and a compression spring. A force is applied to the actuator shaft by a unique double spring combination. The flexible bearings restrict lateral displacement of the actuator and permit frictionless axial displacement of the actuator. The hydraulic valve has a valve spool that moves due, to the position of the actuator, from a position that produces maximum pressure when the coil is de-energized to a position that produces zero pressure when the coil is energized.

Abstract: A solenoid driver circuit has one transistor and a diode coupled to a solenoid and controlled by a logic circuit to apply a desired current to the solenoid. The transistor is turned on and off using a logic flip-flop to sense a voltage comparison with a peak current. A logic signal is generated as a function of the predetermined length of time, and an output signal is coupled to the base of the transistor to control its on/off states. The magnitude of the peak current is a function of an applied analog voltage. Thus, the magnitude of the average current in the solenoid coil is a function of the applied analog voltage. Also, a dither signal can be summed with the analog signal to minimize the effects of solenoid mechanical sticking and magnetic hysteresis.

Abstract: A solenoid driver circuit has reduced power consumption by switching the solenoid coil current during a decay period from an initial peak current to a lower magnitude sustaining peak current. Current decays from the sustaining peak current magnitude for a predetermined length of time to a lower current level. Two transistors and a Zener diode are operatively connected to the solenoid and controlled by a logic circuit to apply the desired current to the solenoid. A sense resistor is coupled in series with the solenoid to sense current in the solenoid. The Zener diode is coupled in parallel with the sense resistor to provide a current decay path from the solenoid parallel to the sense resistor. The two transistors are turned on and off using logic flip-flops to sense voltage comparisons with the initial peak current voltage, the sustaining peak current, and the sustaining low current.

Abstract: A solenoid driver circuit has reduced power consumption by providing relatively fast current decay to a sustaining low current after an initial peak activation current. Subsequent sustaining current peak applications have a smaller magnitude than the initial peak current and are followed by slower decays for a predetermined length of time to a lower current level. Two transistors and a Zener diode are operatively connected to the solenoid and controlled by a logic circuit to apply the desired current to the solenoid. The two transistors are turned on and off using logic flip-flops to sense voltage comparisons with the initial peak current voltage, the sustaining peak current, and the sustaining low current. A logic signal is generated as a function of the predetermined length of time, and an output signal is coupled to the bases of the two transistors to control their on/off states.

Abstract: This specification discloses an apparatus and method for sensing the composition of an engine exhaust gas wherein a signal for compensating for the temperature dependence of the apparatus is derived from engine speed. That is, the output of an exhaust gas sensor is measured with respect to a reference value which is a function of engine speed. The reference value includes the sum of a constant biasing voltage and a voltage representing engine speed.