Abstract: An ignition coil control device includes: an energization control unit that controls to energize an ignition coil by first energization control and second energization control shorter in energization time than the first energization control; a cruise area determination unit that determines that a driving area of a vehicle is located in a cruise area on the basis of a throttle opening and an engine speed; and an integration counter that is incremented every predetermined time when the first energization control is being executed in the cruise area and is decremented every predetermined time in other cases. When a counter value of the integration counter reaches an upper limit value, a cooling process of switching from the first energization control to the second energization control is executed. Such ignition coil control device can appropriately switch energization time while preventing excessive heating of an ignition coil without using a current sensor.

Abstract: An engine combustion control method may include: determining, by a controller, whether a fuel injection timing of an engine matches with an engine running condition of the engine; performing, by the controller, when the fuel injection timing matches with the engine running condition of the engine, a fuel injection variable establishment control (or a variable control of a fuel injection timing) that performs a Wavelet process on a frequency band selected by matching a vibration frequency of a vibration sensor signal to an engine frequency transformed under an engine running condition; and when the fuel injection timing matches with the engine running condition, updating a fuel injection parameter by correcting a target value of a combustion factor based on the fuel injection timing.

Abstract: An ignition system for an internal combustion engine includes an ignition coil forming a part of a primary circuit and a secondary circuit, a power source to supply power to the ignition coil, and a controller to determine whether the ignition coil is a recognized ignition coil based on a measured risetime and a measured current level in the primary circuit, the measured current level being lower than that required to create a breakdown voltage of the ignition coil.

Abstract: A method for determining a need for changing a spark plug of a combustion engine, comprising the following steps: monitoring a current flowing through the spark plug, analyzing the current and thereby determine a time interval that is indicative for the time between application of a voltage to the spark plug and formation of an arc discharge between electrodes of the spark plug, creating a signal indicative of the need to change the spark plug if the duration of the determined time interval is outside predefined bounds.

Abstract: Approaches for controlling dwell time in the ignition system of an internal combustion engine are provided. In one example, a method may include adjusting dwell based on engine operating conditions and further adjusting dwell in a manner proportional to existent spark plug conditions. By constantly assessing spark plug condition during operating of the internal combustion engine, premature wear of the spark plug may be prevented leading to an extension in the service life of spark plug and other ignition system components.

Abstract: An ignition apparatus inputs energy during a predetermined energy input period after the interruption of a primary electric current by an ignition switch and a discharge of an ignition plug caused by a secondary electric current. Moreover, the ignition apparatus includes a blow-off detection unit that detects, during the energy input period IGW after the start of the discharge by the ignition plug, occurrence of blow-off of the discharge. When the secondary electric current I2 drops below a blow-off detection electric current threshold value Ibo at a time instant tbo in a “second region” where it is impossible to perform a re-discharge after blow-off, the blow-off detection unit determines that blow-off has occurred and the ignition apparatus stops the energy input from an energy input unit to an ignition coil. By preventing unnecessary energy input, it is possible to suppress unnecessary electric power consumption and wear of electrodes of the ignition plug.

Abstract: A method for operating an ignition coil is described, wherein a secondary voltage pulse is generated by feeding a primary voltage pulse into a transformer of the ignition coil, and a primary current, a primary voltage, a secondary current and/or a secondary voltage are measured, wherein the course of the primary current, the primary voltage, the secondary voltage and/or the secondary current are monitored and, when a malfunction is determined during subsequent primary voltage pulse, an error signal is generated which indicates that a malfunction has occurred during the previous primary voltage pulse and classifies the malfunction. In addition, a corresponding ignition coil is described.

Abstract: Provided is an engine control device which can suppress a shortage of output terminals of the control unit and an increase of costs even in a multiple-cylinder internal combustion engine equipped with ignition energy supply units of two systems. An engine control device controls a multiple-cylinder engine in which ignition energy supply units of two systems are provided for every cylinder. A signal is transmitted through a common signal line to a plurality of ignition energy supply units of one system among the ignition energy supply units of the two systems to control the ignition energy supply units of the one system.

Abstract: Power control systems are provided including a digital controller configured to control gating mechanism for power switches responsive to an input from a power conversion circuit. The digital controller includes a conversion circuit, a modulation circuit and a gating control circuit. The system further includes an analog circuit comprising a filter, a current limiter and a compare circuit. The current limiter is configured to control a magnitude of a current pulled through a power convertor during a device switching operation.

Abstract: Methods and systems are provided for determining an ignition coil dwell time based on an estimated ignition coil temperature. In one example, a method may include estimating the ignition coil temperature based on heat transfer between engine and the ignition coil, heat transfer between ambient and the ignition coil, and internal resistive heating of the ignition coil.

Abstract: A method prevents the stalling of the engine of a hybrid vehicle (1) equipped with an auxiliary motor (4) and wheels (R1 to R4), pistons (2a to 2d), tank (3), axle (5), drive shaft (6), gearbox (7), connections (8a, 8b), and computer (9). The method uses an estimate of the predicted instantaneous speed of the main engine (2) at its next top dead center, for the purpose of assisting the main engine in a stall situation, via the auxiliary motor which can supply sufficient power to it on a one-off basis to prevent it from stopping. The method defines two levels of instantaneous speed. If the predicted instantaneous speed is located in the intervention zone between the two levels, the auxiliary motor assists the rotation of the main engine to enable it to rotate in the same direction, without stalling.

Abstract: In a system for monitoring the operation of a current loop, which is fed by a current source and has a switching element, an evaluation unit is arranged at the output of the current loop, which evaluation unit is designed to identify a state of the switching element on the basis of the current flowing in the current loop. Furthermore, a signal generation device is arranged in the current loop, which signal generation device is connected to the switching element and is designed to generate a dynamic signal characterizing the state of the switching element in the current loop.

Abstract: An internal combustion engine control apparatus includes: an ignition coil including a primary coil and a secondary coil that are magnetically coupled to each other; a first switch element for turning on and off a current to the primary coil; and a spark plug, for igniting an air-fuel mixture in an internal combustion engine by using a spark discharge caused by switching the first switch element from the ON state to the OFF state. The internal combustion engine control apparatus is configured to: determine occurrence of one of an abnormality in a discharge voltage and a misfire of the spark plug, when the calculated time duration in which a voltage of the primary coil after the switching of the first switch element from the ON state to the OFF state is above a predetermined comparison reference voltage does not fall within an allowable range.

Abstract: Methods and systems are provided for reducing late burn induced cylinder pre-ignition events. In response to a late burn combustion event in a cylinder, ignition coil dwell time is extended in the cylinder to reduce unintended combustion delays. In addition, pre-ignition mitigating actions are performed in a neighboring cylinder that may be prone to pre-ignition induced by the late combustion event.

Abstract: Methods and systems are provided for improving spark robustness. Spark ignition dwell commands are adjusted based on the fuel fraction delivered via direct injection relative to port injection. The approach allows ignition output to better match the ignition requirement of the given fuel combination.

Abstract: An ignition unit (11) has a superimposed voltage generation circuit (17) that feeds, between electrodes of an ignition plug (9), a superimposed voltage of the same direction as a discharge voltage, and in an operation range wherein an engine rotation speed is equal to or lower than a given speed and an engine load is equal to or lower than a given load, feeding of the superimposed voltage is carried out. Although the energization time for a primary coil (15a) is basically set in accordance with the engine rotation speed, the energization time TDWLON for the superimposed voltage feeding is set shorter than the energization time TDWLOFF for the superimposed voltage non-feeding. With this, temperature increase of the ignition unit (11) caused by the feeding of the superimposed voltage is suppressed.

Abstract: A method for controlling an ignition system of an internal combustion engine, with which a device for the detection of misfires is provided, comprises operation of the internal combustion engine in a calibration mode, wherein the calibration mode includes stepwise reduction of the ignition energy by changing the ignition parameter starting from an initial value, detecting the reaching of a combustion failure limit based on the signal of the detection device and again reducing the ignition energy if the combustion failure limit has not yet been reached, and storing the ignition parameter at the point in time of reaching the combustion failure limit. When not in the calibration mode, operation of the ignition system takes place according to the stored ignition parameter. With such feedback control, electrode burn of the spark plugs is reduced, leading to an extension of the service life of the spark plugs.

Abstract: A method for determining a level of spark plug fouling and providing an indication to change the spark plugs of an ignition system is provided. The method includes providing a dwell command on a control wire of an ignition system and generating an indication of a recommendation to change a spark plug of the ignition system based upon a current on the control wire.

Abstract: Methods and systems for compensating for common failures in fail operational systems are described herein. An example system may include a primary controller configured to perform functions of a vehicle such as propulsion, braking and steering and a secondary controller configured in a redundant configuration with the primary controller. The controllers may perform cross-checks of each other and may each perform internal self-checks as well. Additionally, the system may include a control module configured to transfer control of the vehicle between the controllers based on detecting a fault. The control module may detect a common fault of the controllers that causes the control module to output a common fault signal. In response, the system may transfer of control to a safety controller configured to perform the vehicle functions until the system may transfer control back to the primary controller.

Abstract: An ignition control device according to one embodiment of the present invention is configured to, based on a pulse signal to be induced in an ignition coil in accordance with rotation of an internal combustion engine, cause a voltage to be supplied to an ignition plug included in the internal combustion engine, to be generated in the ignition coil. The ignition control device includes: a switching element configured to energize the ignition coil; a biasing unit configured to bias control terminals of the switching element so that the switching element is turned on when the pulse signal is induced; a state detecting unit configured to detect a biased state of the switching element; and a control unit configured to set a timing for controlling de-energization of the ignition coil in response to a result of detection performed by the state detecting unit, and to control the switching element to be turned off in accordance with the timing.

Abstract: Methods and systems are provided for reducing late burn induced cylinder pre-ignition events. In response to a late burn combustion event in a cylinder, ignition coil dwell time is extended in the cylinder to reduce unintended combustion delays. In addition, pre-ignition mitigating actions are performed in a neighboring cylinder that may be prone to pre-ignition induced by the late combustion event.

Abstract: A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.

Abstract: In the ignition device for the battery-less engine, a transistor-type ignition control circuit of the engine including a manual starting device is actuated by using output of the generator driven by the engine, and a primary winding of an ignition coil is powered from the ignition control circuit. In the ignition control circuit, a primary powering time period for powering the primary winding from the ignition control circuit is set shorter than a predetermined time period while an engine speed of the engine is within a low engine speed range below a predetermined engine speed, whereas the primary powering time period is set equal to or longer than the predetermined time period while the engine speed of the engine is within a high engine speed range at and above the predetermined engine speed.

Abstract: A method of controlling the ignition of a gasoline engine having an ignition coil which generates a spark on a spark plug, whereby the instant when coil charging starts is determined for each engine cycle as a function of the angular position of the crankshaft and the rotation speed of the engine, by calculating the ratio between the crankshaft angle of rotation still to pass through before the crankshaft reaches the angular position at which the ignition spark is to be produced, and the time required to charge the coil.

Abstract: An engine control system, a controller for the engine control system, and a method of controlling a combustion process in an internal combustion engine operating at an engine operating condition. The engine control is based on closed-loop control of ignition dwell. Ignition dwell is defined as time or crank angle difference between an end of fuel injection (EOI), or some other aspect of an injection control signal, and a start of combustion (SOC), or some other aspect of an internal combustion event. One or more engine control devices, such as a fuel injector or an exhaust gas recirculation valve may be varied to control ignition dwell. By providing such a closed-loop engine control based on ignition dwell, the air/fuel charge mixture, and/or stratification present in the combustion chamber at the moment combustion starts may be controlled.

Abstract: Applicant has disclosed an improved dual cycle ignition system for automobiles. In the preferred embodiment, the improved ignition system comprises at least two secondary ignition coils wired in a high voltage “OR” configuration using a single high voltage circuit through a distributor, or alternatively a single plug operated directly from diodes connected respectively to associated secondary coils. The ignition coils are set up to alternate sparks, so that even at 8000 engine RPM, each coil is firing as if operating at 4000 RPM, a speed where conventional highly optimized and inexpensive coils are very effective and can reach their full output.

Abstract: An ignition system for an engine includes an igniter configured to selectively ignite a fuel mixture within the engine, an ignition coil associated with the igniter, and a controller in communication with the ignition coil. The controller is configured to energize the ignition coil during a first ignition sequence until a threshold current has been directed to the ignition coil, measure a rise time associated with reaching the threshold current, and calculate a desired ignition duration based on the rise time and a time margin. The controller is also configured to energize the ignition coil during a second ignition sequence, the second ignition sequence lasting for the desired ignition duration.

Abstract: An engine control system, a controller for the engine control system, and a method of controlling a combustion process in an internal combustion engine operating at an engine operating condition. The engine control is based on closed-loop control of ignition dwell. Ignition dwell is defined as time or crank angle difference between an end of fuel injection (EOI), or some other aspect of an injection control signal, and a start of combustion (SOC), or some other aspect of an internal combustion event. One or more engine control devices, such as a fuel injector or an exhaust gas recirculation valve may be varied to control ignition dwell. By providing such a closed-loop engine control based on ignition dwell, the air/fuel charge mixture, and/or stratification present in the combustion chamber at the moment combustion starts may be controlled.

Abstract: An ignition system of an engine may include an ignition device that uses the current that is supplied to an ignition coil to generate spark in the combustion chamber, a starting detecting portion that detects the starting signal for starting a stopped engine, a coolant temperature detecting portion that detects the coolant temperature of the engine, and a power control portion that increases the dwell time of the current that is supplied to the ignition coil for a predetermined time after starting the engine, in a case that the starting signal is detected and the coolant temperature is lower than a predetermined level. Accordingly, if the temperature of the engine is low, the dwell time is increased for a predetermined time such that the spark is effectively formed in the cylinder to sable the starting of the engine in the ignition system of an engine according to the present invention.

Abstract: An object of the present invention is to enable the convergence of the discharge path length of an ignition plug to a target value irrespective of the condition in a cylinder in an ignition control system for an internal combustion engine equipped the ignition plug that can change the discharge path length. To achieve the object, in the present invention, in an ignition control system for an internal combustion engine equipped with a changing device that changes the path length (or discharge path length) of a spark discharge occurring in the discharge gap of the ignition plug, an actual discharge path length or the path length of a spark discharge that actually occurs in the discharge gap is detected, and the changing device is controlled in such a way that the detected actual discharge path length converges to a target discharge path length.

Abstract: A system and method for operating a multiple cylinder internal combustion engine having at least one actuator for controlling charge dilution of at least one cylinder and at least one spark plug per cylinder include attempting to improve combustion quality by modifying ignition energy of the at least one spark plug before modifying charge dilution of the cylinder, and modifying both ignition energy and charge dilution substantially simultaneously to establish combustion if an ionization sense signal associated with the cylinder indicates a misfire.

Abstract: A method for controlling an internal combustion engine with at least two cylinders in the case of irregular running caused by combustion problems has the following steps: measurement of a segment time of a first cylinder during a first time interval T1 in the sequence of operations of the internal combustion engine, with a corresponding first signal being transmitted as a first actual value to a control, sensing of pressure fluctuations in the second cylinder during a second time interval T2 in the sequence of operations of the internal combustion engine, with a corresponding second signal being transmitted as a second actual value to a control and changing of operating parameters of the at least one cylinder by means of the control on the basis of the first and second signal, when the first and the second actual value each deviate from setpoint values stored in the control.

Abstract: An ignition system of an engine may include an ignition device that uses the current that is supplied to an ignition coil to generate spark in the combustion chamber, a starting detecting portion that detects the starting signal for starting a stopped engine, a coolant temperature detecting portion that detects the coolant temperature of the engine, and a power control portion that increases the dwell time of the current that is supplied to the ignition coil for a predetermined time after starting the engine, in a case that the starting signal is detected and the coolant temperature is lower than a predetermined level. Accordingly, if the temperature of the engine is low, the dwell time is increased for a predetermined time such that the spark is effectively formed in the cylinder to sable the starting of the engine in the ignition system of an engine according to the present invention.

Abstract: An internal combustion engine (100) comprises an intake valve (31) which opens and closes an intake port (30), a valve timing adjustment device (200) which adjusts a valve timing of the intake valve (31), a discharge portion (50) including a first electrode (51), a dielectric (53) covering the first electrode (51), a second electrode (52) disposed at a position facing the dielectric (53), and a discharge chamber (55) that is formed between the second electrode (52) and the dielectric (53) so as to face the combustion chamber (13), a voltage impressing mechanism (60) which impresses a voltage to the discharge portion (50) such that the radicals are produced in the discharge chamber (55) by a non-equilibrium plasma discharge, and a controller (70) which controls the valve timing control device (200) to close the intake valve (31) in an intake valve close period in which a piston lowers from an exhaust top dead center to an intake bottom dead center so as to diffuse the radicals in the discharge chamber (55) int

Abstract: A controller for an ignition coil, the controller comprising means for determining a rate of change of current flow through a primary winding of the ignition coil; and means for switching off current flow through the primary winding of the ignition coil as a function of the rate of change of current.

Abstract: A system and a method for controlling an ignition coil charge duration are disclosed, wherein the system includes an ignition coil in electrical communication with a control unit and at least one of an ionization detection circuit and at least one sensor. The control unit controls the ignition coil charge duration to facilitate detection and militate against an undesirable interruption of an ionization output signal during the combustion process.

Abstract: A system for overcurrent threshold correction in an ignition system. The system includes a control circuit and a current detection circuit. The control circuit has a first and second output. The first output of the control circuit charges a first ignition coil, the second output of the control circuit charges a second ignition coil. The overcurrent detection circuit adjusts the detection of an overcurrent condition, when the charging of the first coil overlaps with the charging of the second coil. Further, the control circuit is in communication with the overcurrent detection circuit to disable the first and second output, when the overcurrent condition is detected.

Abstract: A multi-spark ignition system for an internal combustion engine includes ignition coils each of which is mounted on one of spark plugs of an engine, an energy storing circuit, switching elements that repeatedly discharge electric energy stored by the energy storing circuit into the primary coil of the ignition coils; and a control circuit that controls the energy storing circuit and the switching elements according to consolidated signals each of which includes an energy storing command signal for storing electric energy into the energy storing circuit and a joint energy discharging period command signal for discharging the electric energy by the one of the spark plugs.

Abstract: An ignition device (ECU and a drive circuit) for a spark ignition type internal combustion engine that directs an ignition with generation of a predetermined start signal (i.e., falling of an ignition signal) has a circuit for monitoring generation timing of the start signal and for prohibiting the ignition based on the start signal when the start signal is generated at abnormal timing. In particular, the ignition device has a circuit for determining whether the start signal is generated at predetermined start timing and a circuit for prohibiting the ignition based on the start signal when the above circuit determines that the start signal is not generated at the start timing. Thus, damages to the engine and peripheral devices due to the ignition at the abnormal timing can be reduced.

Abstract: An apparatus for producing an ignition spark in an internal combustion engine. The apparatus comprises an inductive ignition device having a primary coil and a secondary coil, flow of current through the primary coil being controlled by an electronic switching element (e.g., a transistor) responsive to a triggering signal. A rotatable body (e.g., the engine flywheel) having detectable features on a periphery thereof is also provided. A sensor device is located adjacent to the rotatable body at a fixed position and is operative to produce an output in response to the detectable features. The apparatus also includes a controller operative to receive an output from the sensor device and responsively produce the triggering signal so as to have a selected dwell time and ignition position.

Abstract: A process is provided for ignition control in a cylinder of an internal combustion engine, using an ignition coil which has a connected primary winding and a secondary winding which is connected to a spark plug, and an ignition control unit which is used to control circuit logic connecting the primary winding by means of a line. According to the process, at the beginning of a working cycle, a switching signal is transmitted from the ignition control unit to the circuit logic, marking the beginning of the working cycle, and the temporal length of the signal is used as a reference length (idle time) for other digital information transmitted to the circuit logic by the ignition control unit.

Abstract: A multi-spark ignition system for an internal combustion engine includes ignition coils each of which is mounted on one of spark plugs of an engine, an energy storing circuit, switching elements that repeatedly discharge electric energy stored by the energy storing circuit into the primary coil of the ignition coils; and a control circuit that controls the energy storing circuit and the switching elements according to consolidated signals each of which includes an energy storing command signal for storing electric energy into the energy storing circuit and a joint energy discharging period command signal for discharging the electric energy by the one of the spark plugs.

Abstract: The present invention relates to methods for robust controlled auto-ignition and spark ignited combustion controls in gasoline direct-injection engines, including transients, using either exhaust re-breathing or a combination of exhaust re-compression and re-breathing valve strategy. These methods are capable of enabling engine operation with either lean of stoichiometric or stoichiometric air/fuel ratio for oxides of nitrogen (NOx) control, with varying exhaust gas recirculation (EGR) rates and throttle valve positions for knock control, and with a combination of homogeneous charge compression ignition (HCCI) and spark ignition (SI) combustion modes to optimize fuel economy over a wide range of engine operating conditions.

Abstract: A method is proposed for controlling an internal combustion engine having a crankshaft, in which from the angular pulses of a sensor a pulse time is formed that is a measure for the rotation of the crankshaft of the internal combustion engine per time unit. At a predetermined target angle of the crankshaft, an ignition of a spark plug and an injection of fuel are to take place. A charging of an ignition coil before the ignition and the injection each require a predetermined time duration. The charging of the ignition coil and the injection are each started before the target angle at a start time dependent on the crankshaft, the start times being calculated by taking into account the time duration of the charging and of the portion of the injection before the target angle, and the pulse time, and the pulse counter. The same pulse time is used for the calculation of the start times of the charging of the ignition coil and of the injection.

Abstract: In a method and an apparatus for operating an injection system of an internal combustion engine, triggering of an injection actuator being performed on the basis of at least one state variable of the injection system, in order to enhance the quantitative accuracy with which fuel is metered provision is made that the at least one state variable is sensed and temporarily stored; the at least one injection actuator is triggered with a triggering pulse of definable pulse duration and definable initial pulse height; during the triggering of the at least one injection actuator, an injection detection is performed; the pulse height of the triggering pulse is incremented in definable steps, at the defined pulse duration, until an injection is detected; and when an injection is detected, the pulse height of the triggering pulse causing the injection is permanently stored as a function of the sensed state variable, and in future operation of the injection system is taken as the basis for triggering the at least one inj

Abstract: A system and method of managing the energy stored in a single ignition coil of a distributor inductive ignition for an engine. The engine comprises a plurality of cylinders and the ignition coil has a primary coil current. The ignition coil has a stored energy and a released energy during an ignition period. A pre-dwell time period and a pre-dwell current level is determined. The stored energy of the ignition coil and the released energy of the ignition coil are balanced during the ignition period at least in part by dwelling the primary coil current in the ignition coil at substantially the pre-dwell current level.

Abstract: In step 400, microcomputer 12 calculates a temperature change amount ?T1 of ignition coil FC caused by the heat generating from the ignition coil FC, based on a previous calculated temperature T(n?1) of ignition coil FC and an engine rotational speed. In step 410, the microcomputer 12 calculates a temperature change amount ?T2 of ignition coil FC caused by the heat received from the engine, based on the previous calculated temperature T(n?1) of ignition coil FC and a cooling water temperature of the engine. In step 420, the microcomputer 12 calculates a temperature change amount ?T3 of ignition coil FC caused by the heat released to the outside, based on the previous calculated temperature T(n?1) of ignition coil FC and an intake air temperature of the engine. Then, in step 430, the microcomputer 12 calculates a present ignition coil temperature T(n) based on these change amounts ?T1, ?T2, and ?T3.

Abstract: An ignition control circuit (12) is responsive to a control signal (ESTC) to apply a drive signal (GD) to a power switching device (22) to conduct ignition coil current (IC) therethrough. A resistor (RS) included within the circuit (12) receives, and dissipates heat generated by, the coil current (IC). The circuit (12) includes a first transistor (QHOT) positioned adjacent to the resistor (RS) such that an operating temperature thereof is near that of the resistor (RS), and a second transistor (QREF) positioned remote from the resistor (RS) and having an operating temperature defining a reference temperature. The first and second transistors (QHOT, QREF) are configured to produce an output voltage (VOUT) proportional to a difference in operating temperatures thereof, and a latch circuit (L1) disables the control signal (ESTC) to thereby turn off the power switching device (22) when the output voltage (VOUT) difference exceeds a reference voltage (VREF).

Abstract: An ignition apparatus for an internal combustion engine is capable of avoiding mis-ignition even if subject to external disturbances when a fail signal is transmitted through a common signal line on which an ignition signal can also be transmitted. An igniter is connected to receive the ignition signal from an ECU, and includes a waveform shaper connected with the signal line and having an input connected in parallel to an input resistance so as to make a voltage at the input higher than a prescribed voltage when the ignition signal flows into the input resistance, and a pulse output circuit connected to the input and having an output for generating the fail signal into which a secondary coil current is converted. The pulse output circuit adjusts a fail signal current such that the voltage at the input when the fail signal flows into the input resistance becomes less than the prescribed voltage.

Abstract: Method for controlling a primary current in an ignition coil of an internal combustion engine with controlled ignition, the current is established in an inductive primary circuit over a given conduction time. The conduction time is calculated by: predetermining the predetermined conduction time, carrying out at least one measurement of the current in the primary circuit at an instant lying in the last tenth of the predetermined conduction time; estimating the current at the end of the predetermined conduction time, as a function of the measurement(s) carried out; optionally correcting the conduction time for the ignition cycle during which the last current measurement was carried out, as a function of the previous estimate and the current desired at the end of the conduction time.