Ignition control system for internal combustion engines with simplified crankshaft sensing and improved coil charging

An electronic ignition system for controlling as a function of a selected engine parameter the ignition instant of an internal combustion engine having a plurality of cylinders, each cylinder having a corresponding piston, and a rotatable crankshaft coupled to each of said pistons to be rotatably driven as combustions occur at said ignition instants in an ordered sequence of said plurality of cylinders, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to at least a selected one of said plurality of cylinders, said electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of indicia, said indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said one reference position;
• (b) means for directly coupling said rotor to said crankshaft without substantial variance in the angular positions of said rotor and said crankshaft relative to each other;
• (c) a single sensor disposed at a sensor position fixed in relation to the rotation of said crankshaft for providing a first train of sensor signals, each sensor signal occurring in time when each of said plurality of reference indicia rotates past said fixed sensor position;
• (d) missing indicium means responsive to each sensor signal of said train for measuring an arc of crankshaft rotation from the corresponding, current indicium, and if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal;
• (e) crankshaft position means responsive to said missing indicium signal for initiating the counting of said first train of sensor signals to provide an initiating manifestation indicative of that position of said crankshaft relative to said reference position, at which a variable arc of crankshaft rotation begins;
• (f) ignition timing means responsive to said initiating manifestation for initiating the counting in response to said sensor signals of a count selected as a function of said selected engine parameter and for terminating at counter overflow said variable arc of crankshaft rotation to provide an ignition signal at said ignition instant;
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• (g) cylinder identifying means responsive to said initiating manifestation for selecting a first cylinder of said ordered sequence for ignition and responsive to said ignition signal for selecting the next cylinder of said ordered sequence.

An electronic ignition system for controlling a dwell period and an anti-dwell period of an internal combustion engine, said internal combustion engine having at least one cylinder, a piston disposed within said cylinder, an ignition coil, a spark plug coupled to said ignition coil, a voltage source, and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said cylinder, said crankshaft having at least one reference position defining the positional relationship of said crankshaft to said cylinder, said electronic ignition system comprising:

• (a) switch means for applying said voltage source to said ignition coil to initiate said dwell period and for disconnecting said voltage source from said ignition coil at spark instant to terminate the dwell period and effect combustion within said cylinder;
• (b) means responsive to the increasing current applied by said voltage source to said ignition coil for measuring that arc of crankshaft rotation required until said current energizes said ignition coil to a reference level;
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• (c) control means for deactuating said switch means to disconnect said voltage source from said ignition coil to thereby initiate said anti-dwell period and for actuating said switch means to apply said voltage source to said ignition coil to thus terminate said anti-dwell period after a variable arc of crankshaft rotation set in accordance with said measured arc to ensure that said ignition coil is sufficiently energized as indicated by said reference level, regardless of crankshaft rotational velocity and voltage source condition.

An electronic ignition system controlling as a function of at least one selected engine parameter the ignition instant of an internal combustion engine having at least one cylinder, said cylinder having a piston and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said cylinder at ignition instant, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to said cylinder, said electronic electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of reference indicia thereon positionally related with respect to said reference position, said reference indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said reference position of said crankshaft;
• (b) a single sensor disposed at a point fixed in relation to the rotation of said crankshaft for providing a train of sensor signals, each sensor signal occurring in time as each of said plurality of said reference indicia rotates past said fixed point;
• (c) missing indicium means responsive to each sensor signal of said train for measuring an arc of crankshaft rotation from the corresponding, current indicium and, if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal;
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• (d) crankshaft position means responsive to said missing indicium and at least one sensor signal of said train to provide an initiate signal indicative of the beginning of a variable arc of crankshaft rotation at a predetermined position with respect to said reference position.

An electronic ignition system for controlling as a function of a selected engine parameter the ignition instants of an internal combustion engine having a plurality of cylinders, each cylinder having a corresponding piston, and a rotatable crankshaft coupled to each of said pistons to be rotatably driven as combustions occur at said ignition instants in an ordered sequence of said plurality of cylinders, where N ignition events occur within said cylinders per revolution of said crankshaft, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to at least a selected one of said plurality of cylinders, said electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of indicia, said indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said one reference position;
• (b) a single sensor disposed at a sensor position fixed in relation to the rotation of said crankshaft for providing a train of sensor signals, each sensor signal occurring in time as each of said plurality of said reference indicia rotates past said fixed sensor position;
• (c) missing indicium means responsive to each sensor signal of said train for measuring an arc of crankshaft rotation from the corresponding, current indicium and, if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal;
• (d) crankshaft position means responsive to said missing indicium signal and at least one sensor signal of said train to provide an initiate signal indicative of said position of said crankshaft relative to said reference position of said selected one cylinder, at which a variable arc of crankshaft rotation begins to define the ignition instant of a corresponding cylinder;
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• (e) synchronization means responsive to said initiate signal and to said N number of ignition events per crankshaft revolution, for generating a sequence of N initiating signals, each initiate signal occurring at a time corresponding to said position of said crankshaft relative to said reference position of a corresponding one of said plurality of cylinders.

An electronic ignition system for controlling as a function of at least one selected engine parameter the ignition instants of an internal combustion engine having at least one cylinder, said cylinder having a piston and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said cylinder at said ignition instants, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to said cylinder, said electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of reference indicia thereon positionally related with respect to said reference position, said reference indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said reference position of said crankshaft;
• (b) a single sensor disposed at a point fixed in relation to the rotation of said crankshaft for providing a train of signals, each signal occurring in time when each of said plurality of reference indicia rotates past said fixed point;
• (c) missing indicium means responsive to each sensor signal of said train for measuring an arc of crankshaft rotation from the corresponding, current indicium, and if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal;
• (d) crankshaft position means initiated by said missing indicium signal for counting said sensor signals of said train to provide a manifestation indicative of crankshaft position, said crankshaft position means provides an initiate signal indicative of the beginning of a variable arc of crankshaft rotation at a predetermined position with respect to said reference position;
• (e) ignition timing means responsive to said initiate signal for measuring said variable crankshaft arc in response to said first-mentioned train of sensor signals to produce an ignition signal, when said measured crankshaft arc equals said variable crankshaft arc set as a function of said one selected engine parameter;
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• (f) closed loop circuit means comprising comparison means coupled to receive said first mentioned train of sensor signals for providing an error signal, oscillator means responsive to said error signal for providing a second train of signals of a frequency proportional to the rotational velocity of said crankshaft, and feedback means for coupling said second train of signals to said comparison means, whereby said comparison means provides said error signal as a function of the phase difference between said signals of first mentioned and said second trains.

An electronic ignition system for controlling a dwell period and an anti-dwell period of an internal combustion engine, said internal combustion engine having at least one cylinder, a piston disposed within said cylinder, an ignition coil, a spark plug coupled to said ignition coil, a voltage source, and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said cylinder, said crankshaft having at least one reference position defining the positional relationship of said crankshaft to said cylinder, said electronic ignition system comprising:

• (a) switch means for applying said voltage source to said ignition coil to initiate said dwell period and for disconnecting said voltage source from said ignition coil at spark instant to terminate the dwell period and effect combustion within said cylinder;
• (b) means responsive to the increasing current applied by said voltage source to said ignition coil for measuring that arc of crankshaft rotation required until said current energizes said ignition coil to a reference level;
• (c) control means for deactuating said switch means to disconnect said voltage source from said ignition coil to thereby initiate said anti-dwell period and for actuating said switch means to apply said voltage source to said ignition coil to thus terminate said anti-dwell period after a variable arc of crankshaft rotation set in accordance with said measured arc to ensure that said ignition coil is sufficiently energized as indicated by said reference level, regardless of crankshaft rotational velocity and voltage source condition;
• (d) means for generating a train of signals of a frequency proportional to the rotational velocity of said crankshaft;
• (e) means for comparing the increased amplitude of the current applied to said ignition coil to provide a termination signal when said current applied to said ignition coil exceeds said predetermined level;
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• (f) said measuring means comprising a counter initiated at the end of said anti-dwell period for counting said train of signals and responsive to said termination signal for terminating the counting of said train of signals to provide a manifestation indicative of said arc of crankshaft rotation.

The electronic ignition system for controlling as a function of at least one selected engine parameter the ignition instants of an internal combustion engine having at least one cylinder, said cylinder having a piston and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said piston at said ignition instants, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to said cylinder, said electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of reference indicia thereon positionally related with respect to said reference position, said reference indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said reference position of said crankshaft;
• (b) a single sensor disposed at a point fixed in relation to the rotation of said crankshaft for providing a first train of signals of a first frequency, each signal occurring in time when each of said plurality of reference indicia rotates past said fixed point;
• (c) closed loop circuit means comprising comparison means coupled to receive said first train of signals for providing an error signal, frequency increasing means for providing a second train of signals of a second frequency greater than said first frequency and proportional to said error signal, and feedback means for coupling said second train of signals to said comparison means, whereby said comparison means provides said error signal as a function of the phase difference between corresponding signals of said first and second trains;
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• (d) missing indicium means responsive to each sensor signal of said first train for counting said second train of signals to provide a manifestation indicative of a measured arc of crankshaft rotation from the corresponding, current indicium, and if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal.

The electronic ignition system for controlling as a function of at least one selected engine parameter a sequence of ignition instants of an internal combustion engine having a plurality of cylinders, each of said cylinders having a piston and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said cylinders at respective ignition instants, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to at least a selected one of said plurality of cylinders, said electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of reference indicia thereon positionally related with respect to said reference position, said reference indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said reference position of said crankshaft;
• (b) a single sensor disposed at a point fixed in relation to the rotation of said crankshaft for providing a first train of signals of a first frequency, each signal of said first train occurring in time as each of said plurality of said reference indicia rotates past said fixed point;
• (c) missing indicium means responsive to each signal of said first train for measuring an arc of crankshaft rotation from the corresponding, current indicium and, if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal;
• (d) crankshaft position means responsive to each of said missing indicium signals for initiating the counting of said signals of said first train to provide a series of crankshaft position signals corresponding to selected of said reference indicium;
• (e) means coupled to receive said first train of signals for providing a second train of signals of a second frequency greater than said first frequency;
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• (f) ignition timing means responsive to selected of said crankshaft position signals for initiating the counting said signals of said second train and, upon obtaining a count selected as a function of said selected engine parameter, for providing an ignition signal at said ignition instant.

An electronic ignition system for controlling a dwell period and an anti-dwell period of an internal combustion engine, said internal combustion engine having at least one cylinder, a piston disposed within said cylinder, an ignition coil, a spark plug coupled to said ignition coil, a voltage source, and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said cylinder, said crankshaft having at least one reference position defining the positional relationship of said crankshaft to said cylinder, said electronic ignition system comprising:

• (a) switch means for applying said voltage source to said ignition coil to initiate said dwell period and for disconnecting said voltage source from said ignition coil at spark instant to terminate said dwell period and effect combustion within said cylinder;
• (b) means for generating a first train of signals of a first frequency proportional to the rotational velocity of said crankshaft;
• (c) means coupled to receive said first train of signals for providing a second train of signals of a second frequency greater than said first frequency;
• (d) ignition timing means for measuring a first variable arc of crankshaft rotation set as function of at least one selected engine parameter, said first variable arc starting at a reference position defining a positional relationship of said crankshaft to said cylinder, said ignition timing means comprising a first counter initiated as said crankshaft rotates past said reference position for counting said signals of said second train and, upon obtaining a first count corresponding to said first variable arc for providing an ignition signal at said spark instant;
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• (e) means for controlling said anti-dwell period as a function of a second variable arc of crankshaft rotation set to insure that said ignition coil is sufficiently energized, said controlling means for initiating said second variable arc at spark instant to deactuate said switch means to disconnect said voltage source from said ignition coil and for terminating said second variable arc to actuate said switch means thus applying said voltage source to said ignition coil, said controlling means comprising a second counter initiated at spark instant for counting said signals of said second train and upon counting a count corresponding to said second variable arc for terminating said anti-dwell period.

The electronic ignition system for controlling as a function at least one selected engine parameter the spark instants of an internal combustion engine having at least one cylinder, said cylinder having a piston and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said piston at said spark instants, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to said cylinder, said electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of reference indicia thereon positionally related with respect to said reference position, said reference indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said reference position of said crankshaft;
• (b) a single sensor disposed at a point fixed in relation to the rotation of said crankshaft for providing a first train of signals of a first frequency, each signal occurring in time when each of said plurality of reference indicia rotates past said fixed point;
• (c) closed loop circuit means comprising comparison means coupled to receive said first train of signals for providing an error signal, an integrating means coupled to said comparison means for integrating said error signal to provide an integrated output, and means for providing a second train of signals of a second frequency proportional to said integrated output and greater than said first frequency, and feedback means for coupling said second train signals to said comparison means, said comparison means provides said error signal as long as there is a phase difference between corresponding signals of said first and second trains, said error signal being indicative of whether said signals of said first train leads or lags said signals of said second train, whereby said second frequency varies accordingly;
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• (d) missing indicium means responsive to each signal of said first train for counting said second train of signals to provide a manifestation indicative of a measured arc of crankshaft rotation from the corresponding, current indicium, and if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal.

An electronic ignition system for controlling as a function of at least one selected engine parameter the ignition instants of an internal combustion engine having at least one cylinder, said cylinder having a piston and a rotatable crankshaft coupled to said piston to be rotatably driven as combustions occur within said piston at said ignition instants, said crankshaft having at least one reference position defining a positional relationship of said crankshaft to said cylinder, said electronic ignition system comprising:

• (a) a rotor affixed to rotate with said crankshaft and having a plurality of reference indicia thereon positionally related with respect to said reference position, said reference indicia being disposed at points equally spaced by a predetermined arc of crankshaft rotation from each other about said rotor, at least one of said points having a missing indicium and disposed in a predetermined relation to said reference position of said crankshaft;
• (b) a single sensor disposed at a point fixed in relation to the rotation of said crankshaft for providing a first train of signals of a first frequency, each signal of said first train occurring in time when each of said plurality of reference indicia rotates past said fixed point, said first train having a missing signal corresponding to said missing indicium;
• (c) means coupled to receive said first train of signals for providing a second train of signals of a second frequency greater than said first frequency, said second frequency tending to vary upon the occurrence of said missing signal;
• (d) missing indicium means responsive to each sensor signal of said train for measuring an arc of crankshaft rotation from the corresponding, current indicium, and if said measured arc of crankshaft rotation exceeds said predetermined arc of crankshaft rotation, for providing a missing indicium signal;
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• (e) means responsive to said missing indicium signal for generating and applying in said first train a replacement signal in place of the said missing signal to said frequency increasing means, whereby said second frequency is not affected by said missing signal.