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

Abstract

An electronic ignition system is disclosed for controlling as a function of at least one selected engine parameter the ignition or spark instants of an internal combustion engine having at least one cylinder with a piston and a rotatable crankshaft coupled to the piston to be rotatably driven as combustions occur within the cylinder at spark instant. The crankshaft has at least one reference position defining a positional relationship of the crankshaft to the cylinder. The electronic ignition system comprises a rotor fixed to rotate with the crankshaft and having a plurality of reference indicia thereon positionally related with respect to the reference position. The reference indicia are disposed at points equally spaced from each other by a predetermined arc of crankshaft rotation about the rotor. At least one of the points has a missing indicium and is disposed in a predetermined relation to the reference position of the crankshaft. A single sensor is disposed at a point fixed in relation to the rotation of the crankshaft for providing a train of sensor signals, each signal occurring in time when each of the plurality of reference indicia rotates past the fixed point. The missing indicium is determined by circuitry responsive to each sensor signal for measuring the arc of crankshaft rotation from the current, corresponding reference indicium and, if the measured arc is greater than the predetermined arc, for providing a missing indicium signal.

I claim: 
     
       1. An electronic ignition system for 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 combustion 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; and   (d) closed loop circuit means comprising comparison means coupled to .[.received.]. .Iadd.receive .Iaddend.said first mentioned train of sensor signals for providing an error signal, oscillator means responsive to said error signal for providing a corrected, second train of signals of a frequency 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 said signals of said first mentioned and said second trains.   
     
     
       2. The electronic ignition system as claimed in claim 1, wherein said reference position is 60° BTDC. 
     
     
       3. The electronic ignition system as claimed in claim 1, wherein there is further included control means for initiating a variable arc of crank shaft rotation and responsive to said one selected engine parameter for terminating said variable crankshaft arc to effect combustion at said ignition instant. 
     
     
       4. The electronic ignition system as claimed in claim 1, wherein there is included 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. 
     
     
       5. The electronic ignition system as claimed in claim 4, wherein 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, and ignition timing means responsive to said initiate signal for measuring said variable crankshaft arc in response to said 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. 
     
     
       6. The electronic ignition system as claimed in claim 1, wherein there is included means for generating and applying a signal to said comparison means at a point in time corresponding to when said missing indicium would have rotated past said fixed sensor point, whereby the frequency of said second train of signals is not affected by the absence of one of said first mentioned train of sensor signals corresponding to said missing indicium. 
     
     
       7. The electronic ignition system as claimed in claim 1, wherein there is included means responsive to said missing indicium signal for generating and applying in said first mentioned train a signal in place of the missing sensor signal to said comparison means, whereby the frequency of said second train of signals is not affected by the absence of one of said sensor signals of said first train. 
     
     
       8. The electronic ignition system as claimed in claim 1, wherein there is included multiplying means for scaling said first mentioned train of sensor signals by a given factor to provide a second train of signals of an increased frequency indicative of the rotational velocity of said crankshaft, said missing indicium means comprises a counter initiated by each sensor signal of said first mentioned train for counting said signals of said second train to provide said missing indicium signal, when said counted signals of said second train exceeds said predetermined arc of crankshaft rotation. 
     
     
       9. The electronic ignition system as claimed in claim 1, wherein there is included crankshaft position means initiated by said missing indicium signal for counting said signals of said second 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, and a position counter responsive to said initiate signal for counting said signals of said second train to produce an ignition signal, when said measured crankshaft arc equals said variable crankshaft arc set as a function of said one selected engine perimeter. 
     
     
       10. The electronic ignition system as claimed in claim 1, wherein there is included crankshaft position means initiated by said missing indicium signal for counting at least one further 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. 
     
     
       11. The electronic ignition system as claimed in claim 10, wherein there is further included ignition timing means responsive to said initiate signal for measuring said variable crankshaft arc in response to said 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 perimeter. 
     
     
       12. 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 combustion 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; and   (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.   
     
     
       13. The electronic ignition system as claimed in claim 12, wherein said crankshaft position means is responsive to the number of ignition events to occur within a single revolution of said crankshaft for providing a corresponding number of initiating signals, each occurring as said crankshaft assumes said positional relationship with a corresponding one of said plurality of cylinders. 
     
     
       14. .[.An.]. .Iadd.A high resolution distributorless .Iaddend.electronic ignition system for controlling a dwell period and an anti-dwell period of .[.an.]. .Iadd.a multi-cylinder .Iaddend.internal combustion engine, said internal combustion engine having .[.at least one cylinder.]. .Iadd.plural cylinders.Iaddend., a piston disposed within .Iadd.each of .Iaddend.said .[.cylinder, an.]. .Iadd.cylinders, at least one .Iaddend.ignition coil .[.spark plug coupled to said ignition coil,.]. .Iadd.arranged to generate spark within said cylinders, .Iaddend.a voltage source, and a rotatable .[.crankshaft.]. .Iadd.shaft .Iaddend.coupled to said .[.piston.]. .Iadd.pistons .Iaddend.to be rotatably driven as combustions occur within said .[.cylinder.]..Iadd.cylinders.Iaddend., said .[.crankshaft.]. .Iadd.shaft .Iaddend.having at least one reference position defining .[.the.]. .Iadd.a .Iaddend.positional relationship of said .[.crankshaft.]. .Iadd.shaft .Iaddend.to .Iadd.at least one of .Iaddend.said .[.cylinder,.]. .Iadd.cylinders, a rotor having sensible indicia being operatively coupled to said shaft, a single sensor for sensing said sensible indicia being operatively coupled to said rotor, said single sensor providing sensor pulses indicative of passage of said sensible indicia relative to said sensor, .Iaddend.said .Iadd.distributorless .Iaddend.electronic ignition system comprising: (a) switch means for .[.applying.]. .Iadd.coupling .Iaddend.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.]. .Iadd.cylinders in a firing order sequence of said cylinders.Iaddend.;   (b) .Iadd.coil current feedback .Iaddend.means.Iadd., .Iaddend.responsive to the .[.increasing.]. current .[.applied.]. .Iadd.induced .Iaddend.by said voltage source to .Iadd.flow through .Iaddend.said ignition coil .Iadd.and responsive to said sensor pulses, .Iaddend.for measuring .[.that arc.]. .Iadd.the amount .Iaddend.of .[.crankshaft.]. .Iadd.shaft .Iaddend.rotation required .[.unitl.]. .Iadd.for .Iaddend.said current .[.energizes.]. .Iadd.to energize .Iaddend.said ignition coil to a reference level; and   (c) control means .Iadd.responsive to said sensor pulses .Iaddend.for .[.deactuating.]. .Iadd.controlling .Iaddend.said switch means to.Iadd.:(i) .Iaddend.disconnect said voltage source from said ignition coil .Iadd.at a spark instant targeted in response to said sensor pulses .Iaddend.to thereby initiate said anti-dwell period .[.and for actuating said switch means to.]..Iadd., and (ii) apply said voltage source to said ignition coil to thus terminate said anti-dwell period after .[.a variable arc.]. .Iadd.an amount .Iaddend.of .[.crank.]. shaft rotation .[.set in accordance with said measured arc.]. .Iadd.that is varied in response to said measured shaft rotation amount .Iaddend.to ensure that said ignition coil is sufficiently energized .[.as indicated by said reference level,.]. regardless of .[.crankshaft.]. .Iadd.shaft .Iaddend.rotational .[.velocity.]. .Iadd.speed .Iaddend.and voltage source condition.Iadd. , said control means being capable of accurately targeting spark instant to desired instants between consecutive said sensor pulses.Iaddend..   
     
     
       15. .[.An.]. .Iadd.A distributorless .Iaddend.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; and   (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.Iadd., .Iaddend.   wherein there is further included ignition timing means responsive to said initiate signal for measuring said variable crankshaft arc in response to said 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.  .[.   
     
     
       16.  The electronic ignition system as claimed in claim 15, wherein there is further included ignition timing means responsive to said initiate signal for measuring said variable crankshaft arc in response to said 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..]. 
     
     
       17. 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 beings to define the ignition instant of a corresponding cylinder; and   (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.   
     
     
       18. The electronic ignition system as claimed in claim 17, wherein to each of said initiate signals for initiating the counting in response to said sensor signals a count selected as a function of said selected engine perimeter and for terminating at counter overflow said variable arc of crankshaft rotation to provide an ignition signal at said ignition instant. 
     
     
       19. The electronic ignition system as claimed in claim 17, wherein there are M of said points disposed about said rotor, and the quotient of M divided by N is a whole number. 
     
     
       20. The electronic ignition system as claimed in claim 17, wherein there is only K sequential points having missing indicium disposed about said rotor, where K equals at least 1. 
     
     
       21. The electronic ignition system as claimed in claim 17, wherein there are 60 of said points disposed about said rotor. 
     
     
       22. 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; and   (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.   
     
     
       23. The electronic ignition system as claimed in claim 22, wherein said crankshaft position means provides a last signal indicative of the passage of that reference indicium immediately preceding said missing indicium, and missing indicium means responsive to said last signal for generating and applying to said comparison means a signal in place of that as would have been generated by said missing indicium, whereby said frequency of said second train of signals is not affected by said missing indicium. 
     
     
       24. The electronic ignition system as claimed in claim 23, wherein said missing indicium means comprises a counter initiated by each sensor signal of said first mentioned train for counting said signals of said second train to provide said missing indicium signal when said counted signals of said second train exceeds said predetermined arc of crankshaft rotation. 
     
     
       25. 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 voltge 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; and   (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.   
     
     
       26. The electronic ignition system as claimed in claim 25, wherein there is included a scaling counter for scaling the frequency of said train of signals as applied to said counter in accordance with said reference level to ensure that said crankshaft arc manifestation will effect the sufficient energization of said ignition coil. 
     
     
       27. The electronic ignition system as claimed in claim 25, wherein there is included a second counter for initiating the counting of said train of signals when said one reference position of said crankshaft rotates past a point fixed with respect to the rotation of said crankshaft and for terminating counting of said train of signals when said counted signals equal said selected engine parameter to set said spark instant and to terminate the dwell period. 
     
     
       28. The electronic ignition system as claimed in claim 27, wherein said control means includes a third counter initiated at spark instant for counting said train of signals and upon counting over a count corresponding to said measured arc, terminating said anti-dwell period. 
     
     
       29. The electronic ignition system as claimed in claim 28, wherein there is included a scaling counter for scaling the frequency of said train of signals as applied to said third counter dependent upon the number of ignition events per revolution of said crankshaft. 
     
     
       30. 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; and   (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.   
     
     
       31. The electronic ignition system as claimed in claim 30, wherein said frequency increasing means comprises a voltage controlled oscillator. 
     
     
       32. The electronic ignition system as claimed in claim 30, wherein said closed loop circuit means further comprises integration means coupled to said comparison means for integrating and storing said error signal to provide an integrated output thereof to said frequency increasing means. 
     
     
       33. The electronic ignition system as claimed in claim 32, wherein said integration means comprises a capacitor to be charged and discharged by said error signal. 
     
     
       34. The electronic ignition system as claimed in claim 30, wherein there is included means responsive to said missing indicium signal for generating and applying to said comparison means a replacement signal in place of that missing signal as would have been generated if said missing indicium were present, whereby the frequency of said second train of signals is not affected by the absence of said missing signal of said first train. 
     
     
       35. The electronic ignition system as claimed in claim 30, wherein there is included means for generating and applying a replacement signal to said comparison means at a point in time corresponding to when said missing indicium would have rotated past said fixed sensor point, whereby the frequency of said second train of signals is not affected by the absence of one signal of said first train corresponding to said missing indicium. 
     
     
       36. The electronic ignition system as claimed in claim 30, wherein there is included means responsive to consecutive signals of said first train for measuring the time interval therebetween and, if said measured time interval is greater than a predetermined interval, for inserting an extra signal into said first train to be applied to said comparison means, whereby the frequency of said second train of signals is maintained. 
     
     
       37. The electronic ignition system as claimed in claim 36, wherein said measuring means comprises a counter responsive to each signal of said first train for counting a clock signal to provide said indication of said time interval. 
     
     
       38. The electronic ignition system as claimed in claim 36, wherein there is further included means responsive to said extra signal for counting said signals of said first train and, if greater than a predetermined number indicative that the rotation of said crankshaft is less than a predetermined rotational velocity for defeating further of said ignition instants. 
     
     
       39. The electronic ignition system as claimed in claim 38, wherein said defeating means comprises a no run counter for counting said signals of said first train. 
     
     
       40. The electronic ignition system as claimed in claim 39, wherein said missing indicium means comprises a missing pulse counter responsive to each signal of said first train for counting signals of said second train for providing said missing indicium signal if said count exceeds a predetermined count, each of said extra signals initiating the counting of said no run counter, said missing indicium signal defeating said counting initiating of said no run counter. 
     
     
       41. The electronic ignition system as claimed in claim 30, wherein said internal combustion engine comprises a plurality of cylinders to be ignited in an ordered sequence, each of said cylinders including an ignition coil and a spark plug coupled to said ignition coil, and said electronic ignition system further comprises a coil decoder responsive to each missing indicium signal for selecting a first cylinder of said ordered sequence for ignition. 
     
     
       42. The electronic ignition system as claimed in claim 41, wherein there is included ignition timing means responsive to said signals of said second train for determining an end of a variable arc of crankshaft rotation to provide an ignition signal threat, said coil decoder responsive to each of said ignition signals for selecting the next cylinder of said ordered sequence for ignition. 
     
     
       43. 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; and   (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.   
     
     
       44. The electronic ignition system as claimed in claim 43, wherein each cylinder of said plurality includes an ignition coil and a sparkplug coupled to said ignition coil, and there is further included a coil counter responsive to each missing indicium signal for initiating the counting of said ignition signals to thereby control the sequential application of current to said ignition coils. 
     
     
       45. 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; and   (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.   
     
     
       46. The electronic ignition system as claimed in claim 45, wherein said means for providing said second train of signals comprises a voltage controlled oscillator .Iadd.responsive to said first train of signals, said voltage controlled oscillator producing said second train of signals at said second frequency, and wherein said second frequency is proportional to said first frequency.Iaddend.. 
     
     
       47. 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; and   (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.   
     
     
       48. The electronic ignition system as claimed in claim 47, wherein in the absence of one of said signals of said first train said comparison means tends to vary said second frequency, and there is further included means responsive to said missing indicium signal for generating and applying in said first train a replacement signal in place of said missing signal to said comparison means, whereby said second frequency is not affected by the absence of one of said signals of said first train. 
     
     
       49. The electronic ignition system as claimed in claim 47, wherein there is included means for measuring the time interval between consecutive signals of said first train and, if said measured time interval exceeds a predetermined time interval, for applying in said first train an added signal to said comparison means. 
     
     
       50. The electronic ignition system as claimed in claim 47, wherein said feedback means includes a divider means for decreasing said second frequency of said signals of said second train. 
     
     
       51. 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; and   (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.   
     
     
       52. The electronic ignition system as claimed in claim 51, where in there is included means responsive to consecutive signals of said first train for measuring the time interval therebetween and, if said measured time interval is greater than predetermined interval, for inserting an extra signal into said first train to be applied to said comparison means, whereby the frequency of said second train of signals is maintained. 
     
     
       53. The electronic ignition system as claimed in claim 52, wherein there is further included means responsive to said extra signal for counting said signals of said first train and, if greater than a predetermined number indicative that the rotation of said crankshaft is less than a predetermined rotational velocity, for defeating further of said ignition instants. 
     
     
       54. The electronic ignition system as claimed in claim 53, wherein said defeating means comprises a no run counter for counting said signals of said first train. 
     
     
       55. The electronic ignition system as claimed in claim 54, wherein said missing indicium means comprises a missing pulse counter responsive to each signal of said first train for counting signals of second train for providing said missing indicium signal if said count exceeds a predetermined count, each of said extra signals initiating the counting of said no run counter, said missing indicium signal defeating said counting initiating of said no run counter. .Iadd. 
     
     
       56.  A single crankshaft sensor distributorless electronic ignition system for electrical coupling to a spark generator for controlling ignition instants of combustion, in an internal combustion engine system of the type including at least one cylinder with a piston disposed therein, said piston capable of reciprocally travelling within said cylinder, said piston being mechanically coupled to rotatably drive a rotatable engine crankshaft in response to combustion within said cylinder, said cylinder also having an electrically actuatable spark generator operatively coupled thereto, said spark generator producing electrical sparks which trigger combustion within said cylinder, said electronic ignition system comprising: a rotor mechanically coupled to rotate with said crankshaft, said rotor defining plural points separated from one another by equal angular spacings, sensible rotor structures being defined by said rotor at said points, said rotor defining a reference point disposed in predefined fixed positional relationship with respect to said plural points, said reference point indicating said crankshaft angular position and piston have a predefined positional relationship with respect to said cylinder;   a single crankshaft sensor operatively coupled to said rotor, said single crankshaft sensor sensing said sensible rotor structures and arranged to generate successive electrical sensor pulses in response to rotation of said rotor structures past said sensor;   a pulse generator for producing a train of repetitive pulses at a rate in excess of the pulse repetition rate of said electrical pulses produced by said single crankshaft sensor;   a reference point detecting circuit electrically coupled to said pulse generator, said reference point detecting circuit detecting, in response to said electrical sensor pulses, rotation of said reference point past said sensor and producing a detection output signal in response to said detection;   a counter coupled to receive and count said successive electrical sensor pulses, said counter being synchronized with said rotor rotation in response to said detection output signal;   an engine speed determining circuit electrically coupled to said single crankshaft sensor and connected to receive said electrical sensor pulses, said engine speed determining circuit determining the speed of rotation of said crankshaft, said engine speed determining circuit continually updating said determined speed in response to said electrical sensor pulses;   an ignition advance angle specifying circuit coupled to said counter and to said engine speed determining circuit, said ignition advance angle specifying circuit specifying a spark advance angle for said cylinder in response to said determined speed and at least one further engine parameter;   a spark instant actuating circuit, operatively coupled to said counter and to said ignition advance angle specifying circuit, said spark instant actuating circuit generating a spark instant control signal adapted for controlling the timing of sparks produced by said spark generator, said spark instant actuating circuit capable of generating said spark instant control signal at timings other than those corresponding to occurrence of said electrical sensor pulses, said spark instant actuating circuit producing said spark instant control signal at a timing specified by said specified spark advance angle in response to (a) said count, and (b) the occurrence of a pulse in said pulse train produced by said pulse generator. .Iaddend. .Iadd.   
     
     
       57.  A system according to claim 56, wherein said sensible structures each comprise a protrusion, and said reference point is defined at an angular position corresponding to at least one of said equally spaced points and comprises at least one missing tooth. .Iaddend. .Iadd. 
     
     
       58.  A system according to claim 56, wherein each of said equal angular spacings corresponds to a predefined arc of crankshaft rotation. .Iaddend. .Iadd. 
     
     
       59.  A system according to claim 56, wherein said reference point detecting circuit detects passage of said reference point at least in part by determining whenever said rotor has rotated through substantially more than a predefined arc of crankshaft rotation without said sensor providing an electrical sensor pulse. .Iaddend. .Iadd.60. A system according to claim 56, wherein said pulse generator is coupled to receive said electrical sensor pulses and provides said train of repetitive pulses at a pulse repetition rate responsive to the pulse repetition rate of said sensor pulses. .Iaddend. .Iadd.61. A system according to claim 60, wherein said pulse generator multiplies the pulse repetition rate of said sensor 
     
     
        pulses to obtain said train of repetitive pulses. .Iaddend. .Iadd.62.  A system according to claim 61, wherein said pulse generator includes a phase locked loop circuit coupled to receive said electrical sensor pulses at an input, said phase locked loop circuit including a divider for setting a predetermined multiplication factor. .Iaddend. .Iadd.63. A system according to claim 56, wherein said single crankshaft sensor comprises a magnetic sensor suitable for sensing magnetic field 
     
     
        fluctuations. .Iaddend. .Iadd.64.  A system according to claim 56, wherein said sensible structures are continually spaced about the periphery of 
     
     
        said rotor. .Iaddend. .Iadd.65.  A system according to claim 56, wherein said reference point indicates said crankshaft is at an angular position such that said piston is sixty degrees from a top dead center position 
     
     
        with respect to said cylinder. .Iaddend. .Iadd.66.  A system according to claim 56, wherein said sensible structures comprise teeth and said reference point detecting circuit comprises a missing tooth detector. 
     
     
        .Iaddend. .Iadd.67.  A system according to claim 56, wherein said reference point detecting circuit includes a missing pulse counter which counts pulses produced by said pulse generator, is reset in response to each said electrical sensor signal, and produces said detection output 
     
     
        signal when said pulse count exceeds a certain count. .Iaddend. .Iadd.68. A system according to claim 56, wherein said counter includes a synchronization counter which is reset in response to said detection 
     
     
        output signal. .Iaddend. .Iadd.69.  A system according to claim 56, further including a cylinder selection circuit which selects between multiple cylinders of said internal combustion engine system in response 
     
     
        to the count output provided by said counter. .Iaddend. .Iadd.70.  A system according to claim 56, wherein said engine speed determining circuit includes a further counter which generates an output signal responsive to the rate of said pulses produced by said pulse generator. 
     
     
        .Iaddend. .Iadd.71.  A system according to claim 56, further including a missing pulse insertion circuit responsive to said pulse train produced by said pulse generator, said missing pulse insertion circuit generating pulses to compensate for pulses missing from said sensor output. .Iaddend. 
     
     
        .Iadd.72.  A system according to claim 56, wherein said ignition advance angle specifying circuit includes a microprocessor which generates spark advance digital data words responsive to said updated determined speed, said spark advance digital data words having at least eight bit 
     
     
        resolution. .Iaddend. .Iadd.73.  A system according to claim 56, wherein said spark instant actuating circuit includes: an ignition coil,   a coil on counter operatively coupled to said sensor, said coil on counter generating a count indicative of the time and/or angular displacement of said crankshaft during which said coil is activated, and   an anti-dwell counter different from and coupled to said coil on counter, said anti-dwell counter targeting charging of said ignition coil in response to said count generated by said coil on counter. .Iaddend.   
     
     
        .Iadd. 4.  A system according to claim 56, wherein: said counter is reset upon receipt of said detection output signal; and   said system further includes a coil selection circuit connected to receive said count output, said coil selection circuit decoding said count output to generate successive coil selection signals specifying an ordered   
     
     
        sequence of engine cylinders. .Iaddend. .Iadd.75.  A high resolution distributorless electronic ignition system for controlling combustion within an internal combustion engine of the type including a rotating shaft and a plurality of cylinders each having a corresponding piston, said pistons driving said shaft to rotate in response to combustion within said cylinders, said electronic ignition system including: a rotor that rotates with said shaft, said rotor having a plurality of angularly spaced sensible structures disposed thereon;   a single sensing arrangement operatively coupled to said rotor, said single sensing arrangement for detecting said sensible structures and for producing sensor signals in response to said detection;   a reference position detecting circuit connected to receive said sensor signals, said reference position detecting circuit detecting, in response to said sensor signals, when said shaft has rotated to a reference position;   a counter, coupled to receive said sensor signals and synchronized by said reference position detecting circuit, said counter providing a count that changes in response to the sensor signals, said count indicating the position of said shaft; and   a spark timing circuit, coupled to receive said count and responsive to said sensor signals, said spark timing circuit for accepting engine speed determined in response to said sensor signals and for generating a spark targeting signal for accurately targeting spark instant within said plurality of cylinders in response to said count and said determined   
     
     
        engine speed. .Iaddend. .Iadd.76.  A distributorless electronic ignition system as in claim 75 further including a spark generating and distributing means coupled to said spark timing circuit, said spark generating and distributing means not being coupled to any rotating shaft except via said sensor signals, said spark generating and distributing means coupling high voltage electrical pulses to spark plugs within said plurality of cylinders in a predetermined ordered sequence at timings responsive to said spark targeting signal so as to trigger combustion within appropriate cylinders at desired timings, said spark generating and distributing means including plural direct fire ignition coils each of which is coupled to substantially simultaneously generate a spark in each of two different engine cylinders. .Iaddend. .Iadd.77. A distributorless electronic ignition system as in claim 75 further including: at least one direct fire ignition coil;   a feedback circuit coupled to said coil for producing an output signal indicating when said coil is charged to a reference level; and   control means, coupled to said feedback circuit output signal, to said spark timing circuit and to said coil, said control means for initiating current supply to said coil at timings determined in response to said feedback circuit output and for interrupting current supply to said coil at timings responsive to said spark targeting signal. .Iaddend. .Iadd.78. A distributorless ignition system as in claim 75 wherein said rotor defines a circumferential surface, said sensible structures comprise teeth substantially regularly spaced on said rotor circumferential surface, and said single sensor comprises a magnetic sensor that detects passage of said metal teeth thereby,   wherein said rotor circumferential surface defines a substantial gap between first and second of said metal teeth, said substantial gap indicating said reference position, said reference position determining circuit detecting, in response to said sensor signals, when said substantial gap has rotated into proximity with said single sensor.   
     
     
        .Iaddend. .Iadd.79.  A high resolution distributorless single crankshaft sensor electronic ignition system for controlling ignition instants within a multi-cylinder internal combustion engine, said internal combustion engine being of the type including a crankshaft and further including a plurality of cylinders each having a corresponding piston, said pistons being operatively coupled to rotatably drive said crankshaft in response to occurrence of combustions within said plurality of cylinders, said crankshaft having a reference position defined with respect to at least one of said plurality of cylinders, said electronic ignition control system including: a rotor operatively coupled to rotate with said crankshaft, said rotor defining a plurality of points angularly spaced about said rotor, said rotor further defining sensible structures disposed on at least some of said points;   a single sensor operatively coupled to said rotor, said single sensor producing a train of sensor signals in response to passage of said sensible structures thereby, said sensor signals occurring in response to passage of said sensible structures by said sensor;   a crankshaft reference position determining circuit connected to receive said train of sensor signals, said reference position determining circuit detecting, in response to said train of sensor signals, when said crankshaft has rotated to said crankshaft reference position, said crankshaft reference position determining circuit including a counter which counts said sensor signals;   a spark timing circuit, coupled to said crankshaft reference position determining circuit, said spark timing circuit generating a spark targeting signal accurately targeting spark instant with respect to instantaneous crankshaft position in response to (a) said detected crankshaft reference position, and (b) said count, said spark timing circuit capable of accurately targeting spark instant between occurrence of said sensor signals;   at least one direct fire ignition coil operatively coupled to said plurality of cylinders;   a feedback circuit coupled to said coil for producing an output signal indicating when said coil is charged to a reference level; and   control means, coupled to said feedback circuit output signal, to said train of sensor pulses, to said spark timing circuit and to said coil, said control means for initiating and disconnecting application of current to said coil in response to said train of sensor pulses, said feedback   
     
     
        circuit output and said spark targeting signal. .Iaddend. .Iadd.80.  A distributorless electronic ignition system as in claim 14 wherein said system includes plural ignition coils, and said system further includes a coil selection circuit coupled to said control means, said coil selection circuit selecting a next one of said plural coils for energization in response to said spark instant. .Iaddend. .Iadd.81. A high resolution distributorless electronic ignition system as in claim 14 wherein said control means includes a first counter circuit for measuring said dwell period, and a second counter circuit operatively coupled to said first 
     
     
        counter circuit for measuring said anti-dwell period. .Iaddend. .Iadd.82. A high resolution distributorless electronic ignition control system as in claim 14 wherein said control means is capable of accurately targeting the beginning of said dwell period between said consecutive sensor pulses. 
     
     
        .Iaddend. .Iadd.83.  A high resolution distributorless electronic ignition control system as in claim 14 wherein said control means includes a redundant fire circuit which determines when said control means has failed to target spark instant and controls said switch means to disconnect said voltage source from said ignition coil at a predetermined value of coil current in response to said coil current sense signal. .Iaddend. 
     
     
        .Iadd.     A high resolution distributorless electronic ignition system as in claim 14 wherein said system further includes a counter which counts said sensor pulses, said control means being operatively coupled to said counter, said control means accurately targeting spark instant to said desired instants between said sensor pulses in response to said sensor pulse count provided by said counter. .Iaddend. .Iadd.85. A high resolution distributorless electronic ignition system as in claim 84 wherein said system further includes a circuit which detects said reference position in response to said sensor pulses and resets said counter in response to such reference position detection. .Iaddend. 
     
     
        .Iadd. 6.  A high resolution distributorless electronic ignition system as in claim 14 wherein said control means includes at least one counter providing a count that is scalable in response to the number of cylinders 
     
     
        of said engine. .Iaddend. .Iadd.87.  A distributorless electronic ignition system as in claim 79 wherein said system includes plural ignition coils, and said system further includes a coil selection circuit coupled to said spark timing circuit, said coil selection circuit selecting a next one of said plural coils for energization in response to said targeted spark 
     
     
        instant. .Iaddend. .Iadd.88.  A distributorless electronic ignition system as in claim 79 wherein said control means includes a first counter circuit for measuring a dwell period, and a second counter circuit operatively coupled to said first counter circuit for controlling an anti-dwell period 
     
     
        by targeting coil cut on. .Iaddend. .Iadd.89.  A distributorless electronic ignition system as in claim 79 wherein said control means includes a counter providing a count that is scaled in response to the number of cylinders of said engine. .Iaddend. .Iadd.90. A distributorless electronic ignition control system as in claim 79 wherein said control means is capable of accurately targeting ignition coil cut on at an 
     
     
        instant between said sensor pulses. .Iaddend. .Iadd.91.  A distributorless electronic ignition control system as in claim 79 wherein said control means includes a redundant fire circuit which determines when said spark timing circuit has failed to target spark instant and causes said ignition coil to generate spark at a default crankshaft position responsive to said 
     
     
        coil current sense signal. .Iaddend. .Iadd.92.  A high resolution distributorless electronic ignition control system as in claim 79 wherein said system further includes a circuit which detects said reference position in response to said sensor pulses and resets said counter in 
     
     
        response to such reference position detection. .Iaddend. .Iadd.93.  A high resolution distributorless electronic ignition system for controlling ignition instants within a multi-cylinder internal combustion engine, said internal combustion engine being of the type including a rotating shaft and further including a plurality of cylinders each having a corresponding piston, said pistons being operatively coupled to rotatably drive said shaft in response to occurrence of combustions within said plurality of cylinders, said shaft having at least one reference position defined with respect to said plurality of cylinders, said distributorless electronic ignition control system including: a rotor operatively coupled to rotate with said shaft, said rotor defining a plurality of points angularly spaced about said rotor, said rotor further defining sensible structures disposed on at least some of said points;   a single sensor operatively coupled to said rotor, said single sensor producing a train of sensor signals in response to passage of said sensible structures thereby, said sensor signals occurring in response to passage of said sensible structures by said sensor;   a counter connected to receive said sensor signals, said counter counting said sensor signals;   at least one direct fire ignition coil operatively coupled to said plurality of cylinders;   a coil current feedback circuit coupled to said coil for producing an output signal indicating when said coil is charged to a reference level;   a spark timing circuit coupled to said counter, said spark timing circuit capable of accurately scheduling coil cut on time and spark instant at times which occur between said sensor pulses in response to said count, said spark timing circuit scheduling coil cut on time to ensure that said coil is sufficiently energized prior to spark instant without being overcharged; and   a switching circuit for initiating and disconnecting application of current to said coil in response to said scheduled coil cut on time and said   
     
     
        scheduled spark instant, respectively. .Iadd.94.  A distributorless electronic ignition system as in claim 93 wherein said spark timing circuit includes a coil on counter and an anti-dwell counter, said coil on counter and said anti-dwell counter each counting during coil charging, said coil on counter providing a count indicative of a time period needed for said coil to charge to said reference level, said anti-dwell counter 
     
     
        controlling when said coil is to be energized. .Iaddend. .Iadd.95.  A distributorless electronic ignition system as in claim 93 wherein said spark timing circuit includes a counter providing a count that is scaled in response to the number of cylinders said engine has. .Iaddend. .Iadd.96. A distributorless electronic ignition system as in claim 93 wherein said system provides spark to plural cylinders A and B in a firing order wherein cylinder A is fired before cylinder B, and wherein said first spark timing circuit employs said coil current feedback circuit output signal generated during coil charging for generating spark in said cylinder A to schedule coil cut on for charging said coil to generate spark in said cylinder B. .Iaddend. .Iadd.97. A distributorless electronic ignition system as in claim 93 wherein said system includes plural ignition coils, and said system further includes a coil selection circuit for selecting a next of said plural ignition coils to be energized in response to said spark instant. .Iaddend. .Iadd.98. A distributorless electronic ignition system as in claim 93 wherein said ignition coil is coupled to plural cylinders, said ignition coil generating a spark causing combustion in one of said plural cylinders and substantially simultaneously generating a spark that does not cause combustion in 
     
     
        another of said plural cylinders. .Iaddend. .Iadd.99.  A distributorless electronic ignition system as in claim 15 wherein said ignition timing means comprises means for providing high resolution measurement of said variable crankshaft arc. .Iaddend. .Iadd.100. A distributorless electronic ignition system as in claim 15 further including plural ignition coils, and a coil selection circuit which selects between said plural ignition coils in response to said ignition signal. .Iaddend. .Iadd.101. An electronic ignition system as in claim 17 wherein said system is 
     
     
        distributorless. .Iaddend. .Iadd.102.  An electronic ignition system as in claim 17 further including plural ignition coils, and a coil selection circuit which selects between said plural ignition coils in response to 
     
     
        ignition signals. .Iaddend. .Iadd.103.  An electronic ignition system as in claim 56 wherein said spark instant actuating circuit includes means for generating, with high resolution, said spark instant control signal. 
     
     
        .Iaddend. .Iadd.104.  An electronic ignition system as in claim 56 wherein said spark instant actuating circuit includes plural direct fire ignition coils, and a coil selection circuit which selects between said plural direct fire ignition coils in response to said spark instant control 
     
     
        signal. .Iaddend. .Iadd.105.  In a distributorless high resolution electronic ignition system for controlling spark instants within a multi-cylinder internal combustion engine, said internal combustion engine including a rotating shaft and further including a plurality of cylinders each having a corresponding piston, an ignition coil arrangement being operatively coupled to said plurality of cylinders, said ignition coil arrangement including at least one ignition coil, said ignition coil arrangement generating sparks occurring at controlled timings in an ordered sequence of said plurality of cylinders, said sparks causing combustion within said cylinders, movement of said pistons in response to occurrence of combustion within said cylinders being coupled to rotatably drive said shaft, a rotor being operatively coupled to rotate with said shaft, said rotor defining a plurality of points angularly spaced about a dimension thereof, said rotor further defining sensible structures disposed at least some of said points, a sensor operatively coupled to said rotor, said sensor producing sensor signals, said sensor signals occurring in response to registry of said sensible structures with said sensor, a method of facilitating full charging of said ignition coil despite variations in at least one of battery voltage, engine speed and coil arrangement characteristics, said method including the following steps: (a) producing a train of pulses in response to said sensor signals;   (b) applying and measuring a charging current to said coil arrangement;   (c) counting, in response to said measurement, pulses in said train which occur during the time said coil arrangement is charged to a predetermined percentage of a full charge so as to provide a count, said predetermined percentages being less than 100%;   (d) disconnecting said charging current from said coil arrangement so as to trigger a spark instant;   (e) storing said count;   (f) counting pulses in said train occurring subsequent to said spark instant; and   (g) repeating said step (b) beginning at an instant responsive to (i) said spark instant; (ii) said stored count, and (iii) said pulses counted by   
     
     
        said counting step (f). .Iaddend. .Iadd.106.  A method as in claim 105 wherein said coil arrangement includes plural coils, and said method further includes the step of selecting the next of said plural coils to be charged in an ordered sequence in response to occurrence of spark instant. .Iaddend. .Iadd.107. A method as in claim 105 wherein said storing step comprises the step of transferring said count to a coil cut-on counter, said counting step (f) comprises the step of causing said coil cut-on counter to change said transferred count in response to pulses in said train, and said repeating step (g) includes the step of applying current to said coil arrangement beginning at an instant at which said changed count reaches a predetermined count. .Iaddend. .Iadd.108. A method as in 
     
     
        claim 107 wherein said predetermined count is zero. .Iaddend. .Iadd.109. A system as in claim 15 wherein said missing indicium means includes an arrangement that multiplies a parameter associated with said sensor signals. .Iaddend. .Iadd.110. A system as in claim 56 further including a multiplying arrangement connected to receive said detection output signal and coupled to said reference point detecting circuit and to said spark instant actuating circuit, said multiplying arrangement multiplying to provide a parameter associated with said detection output signal. 
     
     
        .Iaddend. .Iadd.111.  A system as in claim 75 further including a multiplier coupled to said reference position determining circuit. .Iaddend. .Iadd.112. A system as in claim 75 further including a multiplier coupled to said spark timing circuit, said multiplier for multiplying a parameter associated with said sensor signals. .Iaddend. .Iadd.113. A system as in claim 75 wherein said shaft comprises the crankshaft of said internal combustion engine. .Iaddend. .Iadd.114. A system as in claim 75 wherein said spark timing circuit targets spark instant to occur at precise desired timings between successive sensor signals, said precise desired timings being responsive to said determined engine speed. .Iaddend. .Iadd.115. A system as in claim 75 wherein said counter changes said count upon receipt of sensor signals and resets said count upon detection by said reference position determining arrangement that the shaft has rotated to said reference position. .Iaddend. 
     
     
        .Iadd.      A system as in claim 75 further including a pulse generator that generates pulses at a rate that is higher than the rate of the sensor signals, said spark timing circuit generating said spark targeting signal 
     
     
        at least in part in response to said pulses. .Iaddend. .Iadd.117.  A system as in claim 116 wherein said pulse generator is connected to receive said sensor signals and operates to multiply said sensor signal rate. .Iaddend. .Iadd.118. A system as in claim 75 further including a signal generator that is connected to receive said sensor signals and produces repetitive signals at a frequency that is proportional to and higher than the rate of said sensor signals. .Iaddend. .Iadd.119. A system as in claim 75 wherein said spark timing circuit includes: a backup fire arrangement that targets spark instant to about 12 degrees before top dead center of a particular cylinder in the event that said spark timing circuit is incapable of accurately target spark instant in response to determined engine speed, and   means for selecting the number of said plurality of cylinders. .Iaddend. .Iadd.120. A system as in claim 75 wherein said spark timing circuit includes a processor which generates a digital spark advance value in response at least in part to said determined speed. .Iaddend. .Iadd.121. A system as in claim 79 wherein said spark timing circuit includes a multiplier. .Iaddend. .Iadd.122. A system as in claim 79 wherein said crankshaft reference position determining circuit includes a multiplier. .Iaddend. .Iadd.123. A system as in claim 93 wherein said spark timing circuit includes a multiplier. .Iaddend. .Iadd.124. A method as in claim 105 wherein said step (a) includes multiplying a parameter associated with said train of pulses so as to accurately target triggered spark instant between pulses of said train. .Iaddend.