Electrical control device

Claim 1

IN A CONTROL DEVICE FOR OPERATING A FUEL INJECTION UNIT FOR INTERNAL COMBUSTION ENGINES, SAID DEVICE INCLUDING MEANS FOR GENERATING TRIGGER PULSES IN SYNCHRONISM WITH THE ENGINE SPEED, A MONOSTABLE MULTIVIBRATOR HAVING AN INPUT RESPONSIVE TO SAID TRIGGER PULSES AND ADAPTED TO SWITCH SAID MONOSTABLE MULTIVIBRATOR TO THE UNSTABLE STATE, AN OUTPUT ADAPTED TO FURNISH A CONTROL PULSE WHILE SAID MULTIVIBRATOR IS IN SAID UNSTABLE STATE, SAID CONTROL PULSE HAVING A TRAILING EDGE, FEEDBACK MEANS CONNECTING SAID MULTIVIBRATOR OUTPUT TO SAID MULTIVIBRATOR INPUT, RESPONSIVE TO SAID CONTROL PULSE AND ADAPTED TO MAINTAIN SAID MULTIVIBRATOR IN THE UNSTABLE CONDITION AS A FUNCTION ALSO OF THE MANIFOLD PRESSURE, AND WHEREIN SAID CONTROL PULSE IS ADAPTED TO CAUSE THE OPENING OF ELECTROMAGNETIC VALVES IN SAID FUEL INJECTION UNIT FOR A PERIOD OF TIME CORRESPONDING TO THE DURATION OF SAID CONTROL VOLTAGE TO SYSTEM FOR SUPPLYING A TIME VARYING CONTROL VOLTAGE TO SAID INPUT OF SAID MONOSTABLE MULTIVIBRATOR IN SUCH A MANNER THAT THE TIME DURATION OF THE CONTROL PULSE, AND THEREFORE THE PERIOD OF TIME THE INPUT VALVES OF SAID FUEL INJECTION SYSTEM ARE OPEN, WILL VARY AS A FUNCTION OF THE ENGINE SPEED AS WELL AS MANIFOLD PRESSURE, COMPRISING, IN COMBINATION, STORAGE MEANS ADAPTED TO GENERATE A CONTROL VOLTAGE AS A FUNCTION OF THE ENERGY STORED THEREIN; TIMING MEANS RESPONSIVE TO THE TRAILING EDGE OF SAID CONTROL PULSE, ADAPTED TO PROVIDE A DISCHARGE PATH FOR SAID STORAGE MEANS FOR A PREDETERMINED TIME PERIOD FOLLOWING SAID TRAILING EDGE OF SAID CONTROL PULSE, AND FURTHER ADAPTED TO PROVIDE A RELATIVELY LONG TIME CONSTANT CHARGE PATH TO SAID STORAGE MEANS FROM THE END OF SAID PREDETERMINED TIME PERIOD TO THE OCCURENCE OF THE NEXT TRAILING EDGE OF SAID CONTROL PULSE; CHARGING MEANS RESPONSIVE TO THE TRAILING EDGE OF SAID CONTROL PULSE, ADAPTED TO CHARGE SAID STORAGE MEANS SUBSTANTIALLY INSTANTANEOUSLY, THUS ASSURING THAT THE CONTROL VOLTAGE GENERATED BY SAID STORAGE MEANS IS THE SAME AT THE BEGINNING OF EACH DISCHARGE CYCLE; AND COUPLING MEANS ADAPTED TO COUPLE THE CONTROL VOLTAGE GENERATED BY SAID STORAGE MEANS TO THE INPUT OF SAID MONOSTABLE MULTIVIBRATOR IN SUCH A MANNER AS TO VARY THE WIDTH OF THE CONTROL PULSE IN DEPENDENCE THERETO.