Abstract: A self-powering input buffer includes a first circuit leg that stores a charge, such as in a capacitor and a second circuit leg with a buffer powered by the first circuit leg that detects a state of an input with reference to a threshold. A transistor switch is coupled between the circuit legs. If the buffer detects an input voltage higher than the predetermined threshold the buffer drives the transistor switch ON to conduct current from the first circuit leg to the output. If the buffer detects an input voltage lower than the predetermined threshold the buffer drives the transistor switch OFF to disconnect the first circuit leg from the output. During a voltage dip the capacitor provides supplemental power as long as the input is above the threshold.

Abstract: A solenoid driver (10) capable of detecting the operational status of a solenoid (12) including the position of an armature within a solenoid coil and an operational method. The solenoid driver (10) generates a first solenoid current within the solenoid (12) and measures a first decay time t.sub.1. The first solenoid current is insufficient to pull the armature into the coil of the solenoid (12). A comparator circuit (22) continuously monitors the solenoid current and initiates a timer within a counter circuit (34) to compute the first current decay time. A second solenoid current is generated within the solenoid (12) that is sufficient to pull the armature into the coil of the solenoid (12). The second solenoid current is turned off and a second decay time t.sub.2 is measured. The decay times are stored in storage registers (R1, R2) within a controller (36). The controller (36) compares the measured decay times with stored values and outputs the armature position information over a communications bus (34).

Abstract: An electronic control module (10) includes a circuit substrate (12) containing a plurality of thermal vias (36) and a heat-generating electronic device (26) attached to the thermal vias (36). The circuit substrate (12) is attached to a mounting plate (18) by a plurality of electrically-isolated, thermal attachment pads (20) located at selected positions on an electrically insulating layer (16) overlying a metal baseplate (14). A solder layer (22) functions to both mechanically attach the plurality of thermal vias (36) to the plurality of thermal attachment pads (20), and to provide a thermal dissipation pathway for heat generated by the electronic devices (26). The heat is transferred from the circuit substrate (12) through the plurality of thermal attachment pads (20) to the metal baseplate (14).

Abstract: A knock detection method and apparatus integrates a knock sensor signal (107) over a first period and provides a first integrated knock sensor signal (119), and integrates the knock sensor signal (107) over a second period and provides a second integrated knock sensor signal (139). A knock indication (131) is provided dependent on an amplitude of the first integrated knock sensor signal (119) and an amplitude of the second integrated knock sensor signal (139) and independent of the influence of the variations of the knock sensor (101) potential sensor to sensor gain variation.

Abstract: An electrical interface circuit (200), for use with a zirconium dioxide sensor (202), includes an input differential amplifier (208) having its inverting input coupled to the circuit input (204) to receive a sensor voltage relative to sensor ground potential, and having its output coupled to the circuit output (210) to produce an output voltage relative to circuit ground potential. Additionally a feedback differential amplifier (214) has its inverting input coupled to the circuit output (210), its non-inverting input coupled to sensor ground potential, and its output coupled to the non-inverting input of the input differential amplifier (208) so that voltage change at the circuit input due to change of sensor ground potential relative to circuit ground potential is substantially cancelled.

Abstract: Circuitry is provided which effectively expands one, and preferably two or more, high resolution timed outputs of a microprocessor device such that a larger number of output signals are selectively, and independent of one another, switched to output states at times determined in accordance with the occurrence of the timed outputs of the microprocessor. Essentially, high resolution event time occurrence information is provided by a microprocessor dedicated output port. Previously, information on a microprocessor data bus and address bus is utilized to selectively enable certain desired ones of a plurality of output latches and determine the next desired state of such enabled latches. All of the output latches effectively receive the high resolution timed output signal of the microprocessor. The result is an advantageous and cost effective high resolution expansion of the microprocessor outputs.

Abstract: A detection scheme processes the output signal from a sensor so as to provide an ultimate output signal that is more noise resistant and that has a transition representative of a threshold crossing in the sensor signal. A key part of the detection scheme utilizes an integrated version of the sensor's output signal and compares it to two reference levels. These reference levels are selected to be near the opposite extremes of the amplitude excursions of the integrated sensor signal. Each time the reference levels are exceeded, a binary signal is latched to one of two levels (e.g. high, low), and is further processed to provide the ultimate output signal that is free of multiple, unwanted transitions in the presence of noise.

Abstract: A method and apparatus is disclosed for forming a binary level output signal which has a single transition representative of a threshold crossing in a sensor output signal. The sensor output signal is applied to the inputs of two signal processing circuits, the first of which develops a first signal having a relatively fast transition representing the threshold crossing. The second circuit develops a second output signal that is representative of an integrated version of the sensor signal. In the preferred embodiment, a flip-flop receives the first signal at a clock input and the second signal at a data input. The flip-flop's set input may also receive the second signal. The resultant output signal from the flip-flop has but a single transition representing the threshold crossing, irrespective of noise-induced threshold crossings in the sensor output signal.

Abstract: Electronic engine synchronization and timing apparatus for use in controlling fuel injection and/or spark ignition for an internal combustion engine is disclosed. An engine crankshaft rotates a rotary body having a plurality of radial projections, and a single crankshaft reluctance sensor is utilized to provide pulses in response to the passage of these projections and thereby provide a signal related to crankshaft position. An engine camshaft rotates a rotary body with radial projections at half of the crankshaft speed, and a pair of camshaft sensors provide signals in response to the passage of the camshaft projections which are indicative of the rotational position of the camshaft.

Abstract: In a system including a carburetor for regulating the air/fuel ratio fed to an internal combustion engine, a sensor is positioned in the exhaust pipe to provide a control signal indicating the amount of some exhaust gas constituent, such as oxygen. A control circuit is provided to regulate the position of a carburetor component, to change the air/fuel ratio as a function of the control signal derived from the exhaust gas sensor. This carburetor component is continually displaced, either toward a richer or leaner mixture condition, thus in effect integrating the signal from the exhaust gas sensor which ultimately regulates the air/fuel ratio. Operation of the control circuit is modified as a function of the engine speed and the engine temperature.