Abstract: The present invention encompasses an ignition system with an ignition dwell signal (207) having charge and discharge states for driving at least one energy storage device (105) and at least one spark plug (103). This system applies an essentially periodic switching device (107, 209, 211, 215) for discharging excess energy in the energy storage device (105).

Abstract: A method and apparatus is disclosed for controlling the duration of ionization of spark plugs in an internal combustion engine. Generally, the ionization times of the spark plugs are individually measured and compared against a reference ionization time to develop an error signal representing an undesired deviation from the reference ionization time. Then, the duration of current dwell time in the engine's ignition coil is adjusted so as to change ionization time and reduce the size of the error signal.

Abstract: A technique for detecting misfire due to a fault in the secondary of an automotive ignition system compares the ignition signal developed by the ignition coil, preferably the primary winding thereof, to reference signals. Abnormal results which occur at predetermined times subsequent to the initiation of the ignition signal indicate short circuit and/or open circuit conditions in the ignition system's secondary. In response to such fault conditions, fuel is preferably shut off to the cylinder associated with the misfire.

Abstract: For use with a reluctance sensor, a digital detector (200) accurately detects, in the presence of noise, a valid transition in the sensor's output signal (10, 202). A first flip-flop (216) is used for sensing a positive going edge (310, 334A) in the sensor signal and for providing an inhibit pulse (312, 332, 336) of a first predetermined time period in response thereto. A second flip-flop (218) responds to the end of the inhibit pulse, if the sensor signal is in the high logic state, by sensing a subsequent negative going edge (318, 334B) in the sensor signal. If the negative going edge is sensed, the digital detector indicates that a valid transition in the sensor signal occurred.

Abstract: A brushless direct current motor control system is disclosed in which a permanent magnet rotor induces voltages in phase windings and wherein these voltages are compared to a reference signal to provide for the proper cyclic and sequential energization of the motor drive phase windings. A protection circuit is utilized to couple a reference level, corresponding to the level about which the phase induced signals vary, as an input to the motor control circuit for effective comparison with the phase induced signals so as to provide for the proper sequencing of phase excitation. The protection circuit typically provides a substantially constant voltage drop between the reference level of the induced voltages and the input terminal of the motor control circuit with the protection circuit also preventing any excessively large magnitude voltages from being applied as an input to the motor control circuit.