Abstract: An ignition system with an ignition coil employs a power amplifier driven by a microprocessor for starting and interrupting coil current, in accordance with signals from an engine driven transducer. The power amplifier includes a current limiter, but this does not usually come into operation. Instead, the actual current flowing just before the instant of spark in each engine cycle is measured and the on time of the power amplifier is adjusted for the next cycle to cause the final current to approach a desired value less than the current limit value.

Abstract: A pulse width control circuit for controlling a pulse width of the output signal using a negative feedback signal, which includes a circuit for detecting the pulse width of the output signal. This detector circuit generates a detection output when the pulse width of the output signal is shorter than a predetermined width. There is also provided a circuit operating in response to the detection output, which circuit acts on the control circuit to forcibly vary the feedback signal, resulting in that the pulse width of the output signal is broadened.

Abstract: An ignition time controlling device having a trigger circuit employing a programmable unijunction transistor which will be ON at a timing when a primary short-circuiting current of an ignition coil is at or a little past a peak. The device includes a charging and discharging circuit for the primary short-circuiting current; a switching controlling circuit interrupting the primary short-circuiting current when the trigger circuit is ON; an ignition coil inducing a high voltage in a secondary coil when the primary short-circuiting current is interrupted; a spark plug generating a spark on receiving the high voltage of the secondary winding and an angle advancing circuit connected between the programmable unijunction transistor and the switching controlling circuit.

Abstract: An internal combustion engine ignition system includes an output switching transistor (7), the emitter-collector path of which is in series with the primary winding (5) of an ignition coil (6). To attain a constant amount of ignition energy in the ignition coil (6), the control current for the base of the output switching transistor (7) is supplied by a constant-current source (9), the level of the constant control current being selected such that while the ignition energy is being stored in the ignition coil (6), the saturated operation of the output switching transistor (7) is maintained.

Abstract: An improved ignition system for internal combustion engines including a constant current control circuit for effecting constant current control of an ignition coil primary current, further includes a compensating circuit for controlling a reference voltage, which is to be compared with a detection value of the ignition coil primary current, at a constant value irrespective of a decrease of a power supply voltage, thereby controlling the ignition coil primary current at a given value over a wide range of variations of the power supply voltage including a considerable decrease thereof.

Abstract: An electronically controlled ignition system is provided in which the point in time at which the primary current flowing through the primary winding of the ignition coil starts, is controlled as a function of speed so that the said primary current only reaches the value required for ignition just before the ignition time and in which immediately before the ignition time, it is ascertained whether the primary current has reached the value required for ignition, wherein if there is no primary current or insufficient primary current to prevent ignition during periodic fluctuations in speed, the electronic control arrangement is switched off for a fixed period and the time at which the primary current is used is derived directly from the control signal of the ignition pulse generator and in which, once the switch off period has come to an end, continuous and automatic electronic control is reinstituted.

Abstract: An output stage of a calculator (2) has a transfer function of the form: tc=N.TSD+.epsilon. where .epsilon. is a small and known quantity; t.sub.c is the conduction time of the coil, N is a number of angular fractions or periods of an interpolation signal; and TSD is the period corresponding to one tooth on the starter gear. The device comprises measurement means (1, 32, 36) for measuring the time strictly necessary to obtain the required energy; means (6, 9, 13, 17) for generating signals at each fraction of the angular marking signal in order to obtain a time measurement of a counting window and means (21, 25, 29) for counting and memorizing during this window an interpolation signal of the angular resolution n times higher.

Abstract: An ignition coil control circuit compares the coil input current with a reference level, and the duty ratio of the output current is altered accordingly. The reference level is raised during cold weather operations, raising the duty ratio. Once the operating temperature of the engine rises above a predetermined level, a detector circuit activates a control signal generator which lowers the reference level received by the comparator to lower the duty ratio accordingly.

Abstract: A countdown counter (14) counts out a speed dependent number to determine the start of the dwell period when a comparison number (Z17) is reached which is adjusted dynamically by a regulation counter (17). The countdown counter's contents are reduced by a value dependent upon acceleration when acceleration is present in order to improve the dynamic correction. In the case of strong accelerations these dynamic corrections are insufficient and when such a strong acceleration occurs the regulation counter content is set to a high value to assure a succession of strong ignition sparks. The high value of acceleration necessary for this precaution may be determined by comparing the difference of successive engine speed counts with a predetermined value or it may be determined by the failure of the current in the ignition coil primary to reach some predetermined value.

Abstract: An ignition system has an electronic control unit which produces trigger pulses in response to received ignition control signals, the control unit also receiving test pulses indicating the period of time for which current supplied to the primary winding of the ignition coil is at its maximum value, the control unit extending the test pulses and supplying the extended pulses to a logic circuit which, when a trigger pulse occurs without an extended pulse simultaneously occurring, produces an output signal to indicate misfiring, and to temporarily switch off the control.

Abstract: An electronic ignition system which is responsive to timing signals generated in timed relationship for providing a substantially constant percent excess dwell time. The timing signals are developed across a sensor coil that is floated between first and second inputs of the system. A capacitor is coupled through a buffer circuit to one of the inputs of the system wherein the timing signal is superimposed onto the voltage developed across the capacitor. A charge and discharge circuit comprising a pair of resistive current sources is utilized to charge and discharge the capacitor during operation. The ratio of the resistive components produces a constant percent excess dwell time that is substantially independent to temperature and process variations.

Abstract: An ignition control device includes a signal generating circuit for generating an output signal which has a frequency corresponding to the rotation speed of an engine, a rotation speed indication voltage generating circuit for generating a voltage which has a level corresponding to the rotation speed of engine, a saw-tooth wave generating circuit for generating a saw-tooth wave signal which changes at a frequency corresponding to the output signal from the signal generating circuit and at a rate corresponding to the voltage applied from the rotation speed indication voltage generating circuit, and a control circuit for generating an ignition signal every time when the saw-tooth wave signal has reached a predetermined voltage.

Abstract: The period of conduction of an electronic interrupter of an ignition circuit is made shorter increasingly with falling engine speed in comparison to the duration of the period for which the switching path of the engine driven timing generator maintains its condition immediately before the ignition moment. During the time in which that condition is maintained immediately before changing at the ignition moment a capacitor (26) is provided with a first change (b) of its charge in a first direction and thereafter a second change (c) thereof is produced in the other direction. The switching of the electronic interrupter (7) into the conducting condition occurs when the charge of the capacitor reaches a threshold value during the second change of the charge. That threshold value is modifiable by a regulating value that depends at least in part on the engine speed.

Abstract: An ignition system for the internal combustion engine is provided wherein a retard start timing and a conduction start timing are provided on the basis of an electrical signal produced from a pick-up coil. An ignition timing is provided at a time point following a retard time determined from the retard start timing in accordance with the engine operating conditions while advancing the retard start timing in accordance with the engine r.p.m. Before the lapse of a cut-off period of the ignition coil current required for producing a required ignition pulse, the cut-off state of the ignition coil current is maintained and the conduction start timing is prevented from advancing before the time point immediately following the lapse of the cut-off period.

Abstract: In addition to a first storage circuit in which a sawtooth wave is generated for comparing the ramp voltage with a threshold voltage that is caused to vary with engine conditions, particularly engine speed, for determining when the interruptor switch of the primary circuit of an ignition coil is closed to begin buildup of current therein, an auxiliary storage circuit is provided for generating an auxiliary signal within the duration of which the sawtooth wave of the main charging circuit must return to its starting condition, and another pulse signal present during all but an initial portion of the auxiliary signal for rapidly returning that sawtooth wave to its beginning a new beginning, thus making a longer part of the ignition cycle available for variation of the duration of the period during which the interruptor switch is closed to allow buildup of current in the ignition coil.

Abstract: An ignition system which is responsive to timing signals generated in timed relationship to the operation of an internal combustion engine for providing firing spark to operate the engine. The system uses two capacitors to provide an adaptive dwell system wherein the percent of time that ignition coil current is limited at a fixed magnitude is made variable with respect to the engine rpm.

Abstract: An ignition coil energizing circuit is provided which has a signal generator for generating an output signal having a frequency corresponding to an engine rotational speed, a switching circuit connected to an ignition coil, a current detector for detecting a current flowing through the ignition coil, a duty control for supplying to the switching circuit a control signal having a duty cycle corresponding to a duty cycle of an output signal from the signal generator and controlling a conduction state of the switching circuit, and a current control circuit for controlling the switching circuit in response to an output signal generated from the current detector and maintaining a current flowing through the current detector at a predetermined value.

Abstract: A solid state inductive ignition system for igniting the mixture in the cylinders of an associated engine with a spark of up to 48 to 50 KV occurring at the most desirable position of the pistons for maximum mileage and power with a minimum of undesirable exhaust emissions. Exceptionally wide spark plug gaps are used to aid in igniting extra lean mixtures. The invention includes a novel high voltage spark distribution system utilizing, if desired, a conventional diameter distribution cap while providing sufficient clearance between adjacent spark plug cable outlets to prevent crossfire. Multiple sparks are provided while cranking to insure the ignition of overly rich or lean mixtures and a constant dwell of extremely short duration is used when running to saturate the core of the ignition coil.

Abstract: An electronic ignition system comprising an ignition coil, having the spark gap in circuit with its secondary winding, a primary transistor and a current limiting circuit in circuit with its secondary winding, a filter transistor connected in front of said primary transistor and controlled by a control signal and a resistor network connected in the current path of the filter transistor, the filter transistor and the resistor network being so dimensioned that, during a rise in current in the primary winding, the further transistor is in saturated operation and a jump in the voltage across the resistor network to a constant maximum voltage when the current is limited by the current limiting circuit, a pulse being derivable from the voltage curve at the resistor network.

Abstract: Oscillations which would normally occur when the current in the primary winding of an ignition coil is limited to a predetermined value prior to ignition are suppressed by use of a feedback resistor. Specifically, the basic circuit consists of the primary winding of the ignition coil connected in series with a Darlington transistor configuration which, in turn, is connected in series with a measuring resistor, at a common point. The input of the current control system is connected to the common point through an additional resistor, while the output of the control circuit is connected to the input base of the Darlington configuration. Oscillations which might otherwise occur are suppressed by the use of a feedback resistor connected between the input and output lines of the control circuit.

Abstract: An ignition system for an internal combustion engine in which the primary voltage applied across the primary winding of the ignition coil is detected together with the secondary current flowing through the secondary winding of the ignition coil, and the electrical characteristic of the secondary circuit of the ignition coil supplying the arc energy is calculated on the basis of the detected signals thereby controlling the primary current supplied to the primary winding of the ignition coil on the basis of the result of calculation, so that the secondary circuit of the ignition coil can exhibit the desired electrical characteristic for supplying the arc energy of desired level.

Abstract: A circuit to be utilized in combination with an ignition system which is responsive to a start signal supplied thereto for maintaining the ignition system in a start mode of operation while starting of the internal combustion engine is controlled by the ignition system. The circuit is responsive to termination of the start signal to provide transitioning of the ignition system to a run mode of operation only during the current ramping period when the ignition coil of the ignition system is being charged prior to the end of a firing cycle when the coil is discharged to provide spark to operate the engine. Start retard and transitioning of the system from start to run modes is provided utilizing a single capacitor.

Abstract: An ignition system for an internal combustion engine includes two power transistors respectively connected to opposite ends of the primary winding of an ignition coil to interrupt the primary currents which flow from a power source through the mid-tap of the primary winding. The two power transistors have emitters connected in common and a resistor is connected to the junction of this common connection to detect respective primary currents with the single resistor. A single current control circuit is provided to control the two power transistors in response to the detected respective primary currents.

Abstract: Timing increment signals produced by an engine driven tachogenerator are used for controlling both ignition timing shift and the dwell time of the interruptor switch of the ignition system. Counting of increment pulses by the ignition coil primary current rises to a predetermined value (Io) are measures a dwell time fraction and provides a count result that goes into a computation of which the result measures the duration of a counting of increments between the end of one dwell time and the beginning of the next. For better dynamic behavior the count value representing the dwell time fraction (.beta.t) is corrected in a calculating stage (16-18) by a factor which represents the proportional change in the duration of an increment signal (such a signal at a fixed point in the cycle to the most increment signal).

Abstract: An electronic ignition system having an automatic shutdown feature is disclosed. In a first embodiment of the invention, should an output terminal of an integrated circuit (10, 10a) remain in a high voltage condition for a prolonged period of time, a capacitor (C100) which is charged from a constant voltage and alternately discharged through a terminal (105) of the integrated circuit, is allowed to charge, and gradually reaches the threshold voltage of a transistor (Q200) which is connected to shunting transistor (Q1), which diverts current from transistor (Q2) in series with an ignition coil primary winding (76, 76a) and gradually deenergizes the ignition system. In a second embodiment, a capacitor (C200) is charged from a constant voltage, and alternately discharged by being shorted by an inverting transistor (Q300) connected to a terminal (205) of an integrated circuit (200, 200a), which provides a signal which is the compliment of an output terminal.

Abstract: An off-time control circuit drives an output transistor connected in series with a primary winding of an ignition coil while controlling the off-time in each ignition period so that the ratio T.sub.i /T between the period of time T.sub.i, during which the level of primary current supplied to the primary winding of the ignition coil attains a predetermined setting, and the ignition period can be maintained constant. The output from a current detecting resistor connected to the primary winding is applied to a rising time detecting circuit which detects the rising time of the primary current from the current supply starting time to the time of attainment of the predetermined setting. The off-time control circuit controls the starting time of power supplied to the output transistor depending on the output from the rising time detecting circuit.

Abstract: An ignition timing control system for an internal combustion engine comprising a circuit for generating a reference ignition signal in synchronism with the engine, a circuit for generating a retard ignition signal at a point shifted by a selected shaft angle of the engine from the reference ignition signal, and an ignition circuit for controlling the ignition timing of the engine according to the retard ignition signal.

Abstract: A dwell angle control has three counting devices for detecting acceleration. In a first UP/DOWN counter (17), the count in one direction takes place throughout the time the current in the primary circuit of an ignition coil (25) exceeds a current threshold value (I1). The count in the other direction is constant with respect to time. The counts on the first counter are taken over into a second UP/DOWN counter (11) in response to the input signal, the counting direction also being determined by the input signals. When the count in the second counter (11) reaches an adjustable trigger threshold value, the closure time is initiated, the actual ignition time being fixed by an edge of a sensed signal, or the edge of the signal from an ignition computer. The adjustable trigger threshold value is advantageously determined by a third UP/DOWN counter (12) which is set to a fixed value (X) by an edge of the sensed signal and whose counting direction is also determined by the sensed signals.

Abstract: A contactless ignition system for an internal combustion engine comprises a signal generator generating an AC signal synchronously with the rotation of the engine, a resistor detecting primary current supplied to an ignition coil, a circuit detecting the rising time of the primary current until the primary current attains a predetermined level, and a circuit producing a signal proportional to the rotational speed of the engine. On the basis of the signal indicative of the rising time of the primary current supplied to the ignition coil and the signal proportional to the rotational speed of the engine, an off-time control signal for controlling the off-time of the ignition coil is generated in which the ratio between the duration of the primary current supplied to the ignition coil, being maintained at the predetermined level, and the ignition period is maintained constant. The off-time of the ignition coil is controlled only when the rotational period of the engine is shorter than a predetermined setting.

Abstract: The primary winding of an ignition coil is placed in series with the collor of a switching transistor. In order to protect the transistor against overvoltages, the collector is also connected to a level comparator and the base receives a two-state control signal which is synchronous with the rotation of the engine. One input of the comparator is connected through a divider network to the collector of the transistor and the outer input is connected to a fixed direct-current voltage source. Provision is also made for an error amplifier connected to the output of the comparator, and for a summing circuit which is connected to the control input of the transistor and receives the control signal.

Abstract: Two closed circuits respectively are each comprised of a primary coil of a transformer for plug ignition, a transistor, a diode, a resistor and a common power source. When one of the transistors is conductive during the ignition period, the current in the related closed circuit increases. When the increased current appearing across the associated resistor exceeds a reference value, the associated comparator renders the conducting transistor nonconductive while it renders the other nonconductive transistor conductive, whereby the transistors continues a push-pull operation at given periods. Each diode is inserted either between the associated primary coil and the associated transistor or between the associated primary coil and the common power source.

Abstract: A switching transistor (7, 9) is serially connected with the primary (5) of an ignition coil; current flow therethrough is controlled from an a-c signal generator (16) with respect to an ON threshold level (Ue) to store electromagnetic energy, and an OFF threshold level (Ua) to generate a spark; a variable conductivity circuit (26) controlled from a sensing resistor (8) modifies the response level of the threshold switch (13) with respect to the null or cross-over level of the applied signal. To prevent excessive current flow under idle-speed conditions, in accordance with the invention, the ON threshold level, at least, of the switch is shifted by introducing an auxiliary bias voltage derived from an auxiliary capacitor (36) and connected (37, 38) by the signal source through a diode (38) which prevents application of an auxiliary bias voltage to the threshold switch (13) under extremely low, e.g.

Abstract: A system for controlling the primary current of an ignition coil using a constant current signal having a calculation device to produce a signal for controlling the ON period of the primary current of the ignition coil, wherein a correction calculation device is provided to calculate the corrected value of the constant current period of the ignition coil.

Abstract: An overvoltage protection circuit is galvanically, directly connected across at least part of the secondary winding in the ignition system of an internal combustion engine. The input portion of the overvoltage protection circuit is a voltage divider preferably constituted by RC elements. The voltage at the tap of the voltage divider is applied to a Schmitt trigger. When the voltage across the secondary winding becomes excessively high, the Schmitt trigger output pulse triggers a monostable multivibrator whose output pulse in turn increases the conductivity of a transistor switch located in series with the primary. The increase in primary current tends to oppose further increases in primary and secondary voltages. Alternatively, the output from the multivibrator could be used to shorten the time of current flow in the primary winding in subsequent ignition time intervals or to completely block any subsequent ignition process.

Abstract: A spark circuit for heating equipment used on automobiles in which a switch interrupts current flow in the primary of an ignition coil. A comparator compares the actual value of current flowing in the primary against a predetermined nominal value, and current to the switch is interrupted when the values reach parity, so as to render the switch non-conductive during the interruption with resulting auto-induction in the secondary of the ignition coil.

Abstract: To improve an ignition system as described in U.S. Pat. No. 4,176,645, Jundt et al., in which a threshold switch is provided which controls current flow through the ignition coil, the turn-ON point of the current flow being determined, in part, by an integrator, and to prevent malfunction due to corroded terminals, improper installation and the like, a variable resistance branch, including a transistor 66, is connected across the integrator 31, 44, and so connected that, as the supply voltage drops, the effect of the integrator 31, 44 on the threshold switch 15, 16 is decreased, thus preventing modification of the inherent threshold level of the threshold switch by the action of the integrator.

Abstract: A time period during which current is conducted through a primary winding of an ignition coil of an internal combustion engine is calculated in response to signals corresponding to an actual rotational speed of the engine and the magnitude of a power supply voltage which is applied to the primary winding, respectively. A time for initiating the primary winding current is controlled in accordance with the calculated time period. Such current is conducted for a maximum period of time, which is determined in response to the magnitude of the power supply voltage, so as to avoid excessive heat build-up in the ignition coil. The rotational speed of the engine is determined by counting clock signals during time intervals which correspond to predetermined angular segments of rotation.

Abstract: A control signal the value of which gradually changes in response to the turning on of a switching element connected in series to the primary winding circuit of an ignition coil is generated. By use of this control signal, the voltage across the primary winding is caused to rise slowly when the switching element is on, thus preventing an unnecessary high voltage from being generated across the secondary winding of the ignition coil.

Abstract: A transistorized ignition apparatus for driving plural ignition coils of an internal combustion engine comprising two power transistor circuits, each having a power transistor, and a pick-up coil for generating an ignition timing signal synchronized with the rotation of the engine. A wave-form shaping circuit receives the ignition timing signal and determines the conduction period of the power transistors, including the conduction starting point thereof. Two driver circuits, which are provided for respective power transistor circuits, produce driving signals thereto on the receipt of an output from the wave-form shaping circuit. Each power transistor circuit has a current limiter circuit which decreases the base current of the power transistor depending on the amount of the current flowing therethrough. The currents through the power transistors, therefore, are restricted to respective maximum values and the operations thereof are drawn into the non-saturation region.

Abstract: A contactless ignition system for internal combustion engines controls the closing angle of an engine in response to a signal derived by comparing the AC output of an alternator operated in synchronism with the rotation of the engine with the output of a bias-up circuit adapted to supply a DC bias signal which varies with the speed of the engine. The outputs of the alternator and the bias-up circuit are applied to a voltage comparison circuit and the voltage comparison circuit applies to the bias-up circuit a signal having a frequency which is proportional to the number of revolutions of engine. In response to the signal the bias-up circuit generates a signal proportional to the engine speed and this signal is converted through a non-linear circuit of the bias-up circuit into a DC bias signal whose rate of change is small at low engine speeds but increases with an increase in speed at higher engine speeds.

Abstract: To prevent excessive current flow through the control transistor of a solid-state ignition system in which the control transistor is serially connected with an ignition coil, if the power supply voltage should exceed rated value, the voltage monitoring circuit, including a Zener diode, is connected across the power supply source. The solid-state ignition system includes a control transistor which controls the conduction state of the final or output transistor. The over-voltage circuit additionally controls the conduction state of this control transistor to conductive condition if over-voltage is sensed, thereby causing changeover of the final or output transistor to blocked state. A timing circuit including a capacitor is preferably included in the monitoring circuit so that application of control voltage to the control transistor is gradual, causing changeover of the main or output transistor likewise to be gradual and preventing generation of an undesired ignition event.

Abstract: In order to optimize the on/off ratio of the output switch in an electronic ignition system in which a monostable multivibrator is triggered by rpm-dependent transducer pulses, the time constant of the multivibrator may be changed by altering the discharging characteristics of its timing capacitor. A current-limiting circuit senses the current through the output switch and applies a signal to a circuit point which controls the discharging rate of the timing capacitor. The current-limiting circuit also prevents further increases in the primary coil current when a limiting value is reached.

Abstract: In order to increase the closure angle of an interrupter switch connected in series with the primary winding of an ignition coil with increasing engine speeds, a capacitor is connected to the input of a trigger circuit whose output controls this closure angle. The capacitor is charged through a diode while the trigger circuit is switched out. The voltage across the capacitor shifts the threshold of the trigger circuit in a direction increasing the time that the interrupter switch is conductive. The charge on the capacitor is controlled by a signal generator which furnishes an output signal having an amplitude increasing with increasing engine speeds. The closure angle of the interrupter switch therefore also varies as a function of engine speed.

Abstract: When the engine accelerates, the angle over which the ignition switch is closed prior to initiating the spark is automatically increased. Acceleration of the engine is detected by a comparator which compares the value of a speed-dependent signal in sequential cycles and initiate closure of the ignition switch if a predetermined difference is exceeded between the so-compared signals at a predetermined time in the cycle. Under static or decelerating conditions, the speed-dependent signal is compared, in each cycle, to the output of an integrator circuit. The integrator circuit integrates in a first direction at a first rate up to the above-mentioned predetermined time in the cycle and in the opposite direction at a second predetermined rate for the remainder of the cycle. The average value of the integrator output signal corresponds to the engine speed. When the so-compared signals are equal, the second comparator furnishes an output signal which closes the ignition switch.

Abstract: The voltage across a capacitor is changed in a first direction while the current in the primary winding of the ignition coil increases to a predetermined value less than the value required for ignition and is thereafter changed in a second direction until ignition takes place. The voltage across the capacitor is applied to the inverting input of a difference amplifier constituting a threshold stage controlling the initiation and termination of current flow through the ignition coil. The two changes are symmetrical when the engine speed remains constant. The residual voltage across the capacitor at the end of the second change is maintained until the start of the next subsequent first change, so that the time at which the threshold stage switches in, that is the time at which primary current starts to flow in the ignition coil changes as a function of the residual voltage in the capacitor.

Abstract: A power transistor is connected in series with a DC power supply and the primary winding of an ignition coil. The base of the power transistor is connected to first and second transistors connected in compound fashion. A current limiter circuit is operated when the current in the primary winding reaches a predetermined value, thus controlling the first transistor. The second transistor is controlled by and the current thereof limited by the first transistor on the one hand and on the other hand subjects the power transistor to on-off control in accordance with the ignition timing signal synchronous with the engine r.p.m.

Abstract: When the current through the primary winding of an ignition coil of an ignition system in an internal combustion engine has increased to a predetermined value, base current for a power transistor connected in series with the coil is shunted away, causing a rise in voltage across the primary winding. When the voltage rise across the primary winding has reached a maximum allowable value less than the value required to cause the generation of a spark, the transistor is switched back to the fully conductive state. This cycle is repeated during the time the transistor would normally be conductive and terminates at the ignition time, that is at the time the transistor is blocked by the ignition timing circuit of the internal combustion engine to create the spark.

Abstract: An ignition apparatus for an internal combustion engine is disclosed in which a current control circuit for so limiting the collector current of a power transistor for controlling the primary current of an ignition coil that the collector current may not exceed a predetermined value, is provided. The current control circuit comprises a circuit for generating a preset reference voltage and a comparison circuit for comparing the reference voltage with a voltage proportional to the collector current of the power transistor, and controls the conductivity of the drive transistor for controlling the drive current for the power transistor in accordance with the output signal of the comparison circuit.

Abstract: In a known ignition system, the emitter-collector circuit of the ignition transistor is connected in series with the primary winding of the ignition coil and with a precision resistor. When the voltage across the latter exceeds a predetermined value, an auxiliary transistor is switched to a conductive state. The emitter-collector circuit of the auxiliary transistor is connected to the base of the ignition transistor and, when conductive, prevents further increases of current through the primary winding of the ignition coil. To protect this circuit, a series circuit including two Zener diodes is connected between the base and collector of the ignition transistor. Further, a voltage divider is connected in parallel with the emitter-collector circuit of the ignition transistor and an additional resistor is connected between the base and the emitter thereof.

Abstract: To prevent misfires, the current through an ignition coil is increased in response to an error signal indicating that the actual spark duration was less than a predetermined minimum spark duration. At the start of the spark, a capacitor is discharged at a known rate. The time required for the voltage across the capacitor to reach a predetermined level is the desired spark duration. This regulation of ignition current causes the spark duration to be very close to the minimum spark duration, thereby cutting losses in the apparatus.