Ignition system for internal combustion engine

Claim 2

An ignition system for use with an internal combustion engine comprising: ignition time-detection means for developing in use ignition signals corresponding to the ignition timing of an internal combustion engine varying in time in dependence upon the speed of rotation of said engine; a switching circuit receptive of said ignition signals and having two states and comprising means responsive to said ignition signals for switching into one state for a predetermined time for each ignition signal inversely proportional to the frequency of said ignition signals and means for developing switching signals corresponding in frequency and duration to said one state; and an ignition circuit receptive of said switching signals for developing spark signals for developing ignition sparks said spark signals corresponding in frequency and duration to said switching signals; wherein said switching circuit comprises a monostable multivibrator including a pair of first and second semiconductor elements, each having an operating state, a chargeable and dischargeable capacitor being dischargeable when said second semiconductor element is in said operating state, means defining a capacitor charging circuit connected to said capacitor including a resistor, and means defining a capacitor discharging circuit connected to said capacitor including a semiconductor rectifier element connected across said resistor, said rectifier element being so poled as to be conductive with respect to a flow of discharging current from said capacitor and when conductive, shortcircuiting said resistor.

Claim 3

An ignition system for use with an internal combustion engine comprising; ignition time-detection means for developing in use ignition signals corresponding to the ignition timing of an internal combustion engine varying in time in dependence upon the speed of rotation of said engine; a switching circuit receptive of said ignition signals and having two states and comprising means responsive to said ignition signals for switching into one state for a predetermined time for each ignition signal inversely proportional to the frequency of said ignition signals and means for developing switching signals corresponding in frequency and duration to said one state; and an ignition circuit receptive of said switching signals for developing spark signals for developing ignition sparks, said spark signals corresponding in frequency and duration to said switching signals; wherein said switching circuit comprises a monostable multivibrator including a pair of first and second semiconductor elements, each having an Operating state, a triggering circuit for triggering said first semiconductor element, a chargeable and dischargeable capacitor being dischargeable when said second semiconductor element is in said operating state, means defining a charging circuit connected to said capacitor including a resistor, and means defining a discharging circuit connected to said capacitor including a semiconductor rectifier element connected across said resistor, said rectifier element being so poled as to be conductive with respect to a flow of discharging current from said capacitor and when conductive, shortcircuiting said resistor, and wherein said ignition time-detection means includes a signal generator responsive to the rotational movement of the engine for generating said ignition signal, a third semiconductor element having an inoperative state and an operating state responsive to said ignition signal from said signal generator, another chargeable and dischargeable capacitor charged when said third semiconductor element is in said inoperative state and discharged through said semiconductor element when it is in said operating state, a first semiconductor rectifier element poled forwardly with respect to the polarity with which said another capacitor is charged, and a second semiconductor rectifier element poled reversely with respect to said polarity of said another capacitor and connected to said triggering circuit for said first semiconductor element included in said monostable multivibrator.

Claim 4

An ignition system for use with an internal combustion engine comprising; ignition time-detection means for developing in use ignition signals corresponding to the ignition timing of an internal combustion engine varying in time in dependence upon the speed of rotation of said engine; a switching circuit receptive of said ignition signals and having two states and comprising means responsive to said ignition signals for switching into one state for a predetermined time for each ignition signal inversely proportional to the frequency of said ignition signals and means for developing switching signals corresponding in frequency and duration to said one state; and an ignition circuit receptive of said switching signals for developing spark signals for developing ignition sparks, said spark signals corresponding in frequency and duration to said switching signals; wherein said switching circuit comprises a monostable multivibrator including a pair of first and second semiconductor elements, each having an Operating state, a triggering circuit for triggering said first semiconductor element, a chargeable and dischargeable capacitor being dischargeable when said second semiconductor element is in said operating state, means defining a charging circuit connected to said capacitor including a resistor, and means defining a discharging circuit connected to said capacitor including a semiconductor rectifier element connected across said resistor, said rectifier element being so poled as to be conductive with respect to a flow of discharging current from said capacitor and when conductive, shortcircuiting said resistor, and wherein said ignition time-detection means includes a signal generator responsive to the rotational movement of the engine for generating said ignition signal, a third semiconductor element having an inoperative state and an operating state responsive to said ignition signal from said signal generator, another chargeable and dischargeable capacitor charged when said third semiconductor element is in said inoperative state and discharged through said semiconductor element when it is in said operating state, a first semiconductor rectifier element poled forwardly with respect to the polarity with which said another capacitor is charged, and a second semiconductor rectifier element poled reversely with respect to said polarity of said another capacitor and connected to said triggering circuit for said first semiconductor element included in said monostable multivibrator.

Claim 5

An ignition system for use with an internal combustion engine comprising: means for developing in use first signals corresponding to the ignition timing of an internal combustion engine varying in frequency in dependence upon the speed of rotation of said engine; a switching circuit receptive of said first signals and having two states and comprising means responsive to said first signals for switching into one state for each first signal for a variable duration of time determinable by the frequency of said first signals, and means for developing second signals corresponding in frequency and duration to said one state thereby having a frequency corresponding to the frequency of said first signals; an ignition circuit receptive of said second signals for developing engine ignition signals corresponding in frequency and duration to said second signals; wherein said switching circuit comprises; a monostable multivibrator having means therein defining each variable duration of time comprising a chargeable and dischargeable capacitor, voltage supply means having a predetermined voltage and for developing a voltage charge across said capacitor in the other state, means defining a capacitor charge path connected to said capacitor and receptive of said predetermined voltage for charging said capacitor in said other state and having a first time constant, and means defining a capacitor discharge path connected to said capacitor for discharging same in said one state and having a second time constant wherein said first time constant is substantially greater than said second time constant, whereby as said speed of rotation of said engine increases the time for charging said capacitor decreases decresing the peak voltage charge across said capacitor thereby decreasing the time for discharging same; and wherein said means defining said charge path and said means defining said discharge path comprise common circuit elements including; a resistor, and a rectifier element connected in parallel with said resistor and poled to be in a non-conductive state during the charging of said capacitor and in a conductive state during the discharge of said capacitor thereby shortcircuiting said resistor.

Claim 6

An ignition system for use with an internal combustion engine comprising: means for developing in use first signals corresponding to the ignition timing of an internal combustion engine varying in frequency in dependence upon the speed of rotation of said engine; a switching circuit receptive of said first signals and having two states and comprising means responsive to said first signals for switching into one state for each first signal for a variable duration of time determinable by the frequency of said first signals, and means for developing second signals corresponding in frequency and duration to said one state thereby having a frequency corresponding to the frequency of said first signals; an ignition circuit receptive of said second signals for developing engine ignition signals corresponding in frequency and duration to said second signals; wherein said switching circuit comprises; a monostable multivibrator having means therein defining each variable duration of time comprising a chargeable and dischargeable capacitor, voltage supply means having a predetermined voltage and for developing a voltage charge across said capacitor in the other state, means defining a capacitor charge path connected to said capacitor and receptive of said predetermined voltage for charging said capacitor in said other state and having a first time constant, and means defining a capacitor discharge path connected to said capacitor for discharging same in said one state and having a second time constant wherein said first time constant is substantially greater than said second time constant, whereby as said speed of rotation of said engine increases the time for charging said capacitor decreases decresing the peak voltage charge across said capacitor thereby decreasing the time for discharging same; and wherein said means defining said charge path and said means defining said discharge path comprise common circuit elements including; a resistor, and a rectifier element connected in parallel with said resistor and poled to be in a non-conductive state during the charging of said capacitor and in a conductive state during the discharge of said capacitor thereby shortcircuiting said resistor.

Claim 7

An ignition system according to claim 3, wherein said rectifier element comprises a semiconductor diode.