Abstract: An ignition system for internal combustion engines has two spark plugs per cylinder. The spark plugs are connected in a parallel circuit with the same end of an ignition coil.

Abstract: An apparatus for controlling an internal combustion engine that automatically corrects an error of a reference position to prevent an erroneous calculation of a controlled-parameter so as to accurately control the internal combustion engine, the apparatus for controlling an internal combustion engine having a period measuring section for measuring a period of a plurality of reference-position areas and a period of a plurality of areas corresponding to cylinders of a reference-position signal, an angular error detection section for detecting an angular error in each reference-position area in accordance with the period of the reference-position areas and the period of the areas corresponding to the cylinders and an error discrimination section that discriminates validity of the angular error to generate a final angular error, wherein a timer control section corrects the controlled-parameter in accordance with the final angular error, and a control time setting section corrects a time controlled by the timer in

Abstract: Apparatus and method for a plasma discharge for ignition in an internal combustion engine. A digital electronic system controls ignition performance and can provide an ignition discharge throughout an entire power stroke of a piston in a cylinder. The discharge can be controlled by a signal from a conventional distributor, crank trigger or other source.

Abstract: A distributorless ignition system for an internal combustion engine which discharges only one spark plug at a time. A high-level reversible voltage potential in selectively induced in the secondary winding of an ignition coil. Opposing diodes connected to the secondary winding permit application of the induced voltage across only one of two spark plug gaps, the central electrode of the spark plug being negatively charged with respect to ground to effectuate discharge with reduced power requirements and electrode erosion.

Abstract: A connection part for an ignition device, arranged between an ignition coil and a spark plug for incorporating in a cylinder head of an internal combustion engine, has an isolation housing, a high voltage switching element located in the isolation housing and during application of a trigger voltage is transferred reversibly in an electrically jump-like fashion to an electrically conductive condition, a first junction element located at one end of the high voltage switching element and connected with one pole of the latter and also connectable with a high voltage terminal of the ignition coil which leads to an output voltage of the ignition coil, a second junction element provided at another end of the high voltage switching element and connected with another pole of the latter and provided for receiving a terminal pin of the spark plug, and an element associated with the isolation housing for increasing a capacity region between the high voltage switching element and the first junction element.

Abstract: An ignitor comprising a casing, an ignition coil (1) disposed within the casing (20), a power-transistor package (26) disposed within the casing (20) and electrically connected to the ignition coil (1) for interrupting an electric current flowing through the ignition coil (1), an electrical connector (21) mechanically attached to the power-transistor package (26) and for electrically connecting the ignition coil (1) and the power transistor package (26) to an external circuit and an electrically insulating resin (28) filled within the casing for hermetically sealing and supporting therein the ignition coil (1) and the power-transistor package (26). The power transistor package (26) may comprises a holder (23) mounting the mold resin package and electrically connecting the electrical connector (21) to the power-transistor package (26) and the electrical connector (21) may be fixed to the holder (23) by fastening means (22, 24).

Abstract: An apparatus for controlling operation of an internal combustion engine on the basis of a plurality of cylinder identification signals and a reference position signal includes a control means for making it possible to continue the engine operation control even when one of the above signals suffers from abnormality. The control means includes a first decision means for making decision as to whether or not the individual cylinder identification signals are normal, and a first back-up means for controlling the engine on the basis of other cylinder identification signal(s) when one of said cylinder identification signals is decided to be not normal.

Abstract: An apparatus (8) is provided for controlling ignition in an engine having a ignition system (10), an engine cylinder sensor (48), and a piston disposed in the cylinder and being movable to a top dead center (TDC) position. The cylinder sensor (48) produces a first signal representing the position of the piston within the cylinder and having a frequency responsive to engine speed. The ignition system (10) includes a transformer (24) having a primary coil (26) which is energized in response to a cylinder select signal to produce sparking across an associated spark plug gap (22). A first circuit (98) is provided for sensing a delay between production of the cylinder select signal and the time at which current through a respective primary coil exceeds a preselected current level, and responsively producing a timing error signal.

Abstract: An energy-on-demand vehicular ignition system, particularly a coil-per-plug system ("CPP") with a programmable re-striking and minimum single-strike energy output whereby at idle engine speed and lowest load, each coil will be re-struck or discharged the maximum number of times permitted by the coil design within a limited time interval representing the beginning of the combustion event and occurring within 0-2% MFB, and preferably within 0.5% MFB, of the ignitable air fuel mixture within the combustion chamber. The CPP system also includes programmable re-striking whereby the system will default to a single-strike at conditions above a predetermined range of operating conditions, in particular, at a particular engine speed condition and a particular engine partial load condition. In between the conditions at (i) idle engine speed and lowest load on the one hand and, (ii) a predetermined engine speed and partial load condition.

Abstract: An engine control apparatus for discriminating each cylinder of an engine comprises a crank angle rotor (M1) having a configuration representing a crank angle of an engine; a crank angle sensor (M2) operatively associated with the crank angle rotor (M1) to generate a crank angle signal in accordance with the configuration of the crank angle rotor (M1). The configuration of the crank angle rotor (M1) includes first and second silent sections. The first silent section is cooperative with the crank angle sensor (M1) to constitute a part (M3) for generating a first level non-pulsation component of the crank angle signal. The second silent section being cooperative with said crank angle sensor to constitute a part (M4) for generating a second level non-pulsation component of the crank angle signal.

Abstract: An ignition apparatus for an internal combustion engine includes a reduced number of component parts which can be arranged or laid out without difficulty within a limited space such as a vehicle engine room. The apparatus can be manufactured at low costs and it is also highly resistant to electrical noise from adjacent electrical and electronic elements and hence has improved reliability in operation. The apparatus includes an ignition coil connected to a spark plug which has electrodes present in a combustion chamber of a cylinder, a switch unit for controlling power supply to the ignition coil, and an ion current sensing unit connected to the spark plug for sensing an ion current generated between the electrodes of the spark plug during combustion of a mixture in the combustion chamber. The ignition coil and the switch unit, or the ion current sensing unit and the switch unit, or all of these elements, are integrally formed with each other to provide an integral assembly.

Abstract: An ignition system of electronic distribution type for an internal combustion engine with which merits of sharing circuits and elements can be expected with satisfactory result, in which wires of a GND line will not be disconnected by fusion even under a condition of abnormal power supply, and in which the engine will not be stalled even in a mode of simultaneously igniting two cylinders, thus enabling the limp-form traveling and made start-up with simultaneous ignition of two cylinders. To this end, power transistors 20 through 25 for power supply control and feedback control circuits 30 through 35 for limiting currents are respectively provided to control ignition coils 4 through 9 in one-to-one relation. A total of two systems of resistance devices 17a, 17b for detecting currents are provided with each resistance device operating a respective group of three cylinders. The feedback control circuits and the resistance devices for detecting currents are formed on a thick-film circuit board 60.

Abstract: An electronic distributor for an internal combustion engine, having a plurality of switching elements for conducting and breaking currents flowing to a plurality of ignition coils, a first lead frame for separately flowing the currents of the plurality of switching elements to the plurality of ignition coils and a second single lead frame for dropping current levels of currents of at least two switching elements of the plurality of switching elements to a common electric potential, characterized in that a resistance value of the first lead frames has been set to be larger than a resistance value of the second lead frame.

Abstract: Methods and apparatus for detecting low impedance short circuits in a secondary winding circuit of a coil of a distributorless ignition system (DIS) by analyzing spark discharge signals on a primary winding of the ignition coil. In one embodiment, the duration times of the spark discharge signals are compared to a threshold spark duration time, with a low impedance short circuit being indicated if the threshold spark duration time is exceeded. In another embodiment, two or more spark dwell signals are applied to the primary of the ignition coil for each spark event of each associated pair of engine cylinders. A first or base time period is determined for the first dwell signal by measuring the time it takes the first dwell signal to produce a preselected current flow in the primary winding. A second time period is then determined by measuring the time it takes the second dwell signal to produce the same preselected current flow in the primary winding.

Abstract: A crank angle and cylinder number detecting system for an engine has a disc secured to a camshaft of the engine and, a plurality of projections are formed on a periphery of the disc. A sensor is provided adjacent the disc so as to produce pulses. A pattern of interval arrangement of pulses is determined. From the determined pattern, a crank angle of the engine and a cylinder number are precisely determined in a short time.

Abstract: An ignition coil assembly for an internal combustion engine including an ignition coil housing having integrally molded mounting members arranged on the outer perimeter of the housing in non-interfering relationship with the internal coil/core assembly components. C-Shaped laminated cores are encased entirely within the ignition assembly housing material or encased in an elastomer such as a rubber modified polypropylene and inserted into the housing assembly. The ignition coil assembly provides for use either in a internal combustion engine with a distributor-based or distributor-less ignition system.

Abstract: The invention relates to a semiconductor switch, in particular as an ignition voltage switch for applying an ignition voltage to a spark plug of an internal combustion engine, having a cascade circuit formed of series-connected semiconductor components for connecting an operating voltage through to a load, wherein the semiconductor components each have a depletion-layer capacitance, and the connection existing between each two semiconductor components forms a parasitic ground capacitance determined by the electrical field distribution. For symmetrical voltage distribution without additional wiring elements, it is provided that a breakover current (i.sub.k) flowing through the semiconductor components (T.sub.1 -T.sub.n) prior to attainment of the conductive state is located, relative to a displacement current (i.sub.ver), within the range i.sub.ver <i.sub.k <a.multidot.i.sub.ver, wherein the displacement current (i.sub.ver) is brought about by a voltage increase (du.sub.o /dt) in the operating voltage u.

Abstract: An ignition apparatus for an internal combustion engine includes a reduced number of component parts which can be arranged or laid out without difficulty within a limited space such as a vehicle engine room. The apparatus can be manufactured at low costs and it is also highly resistant to electrical noise from adjacent electrical and electronic elements and hence has improved reliability in operation. The apparatus includes an ignition coil connected to a spark plug which has electrodes present in a combustion chamber of a cylinder, a switch unit for controlling power supply to the ignition coil, and an ion current sensing unit connected to the spark plug for sensing an ion current generated between the electrodes of the spark plug during combustion of a mixture in the combustion chamber. The ignition coil and the switch unit, or the ion current sensing unit and the switch unit, or all of these elements, are integrally formed with each other to provide an integral assembly.

Abstract: An inductive discharge ignition system for an internal combustion engine uses two ignition transformers with their associated circuitry. One transformer is employed in a Kettering type high voltage system. The other transformer is used in a low voltage high current output system. The Kettering system initiates spark plug arcing. When the arc is established the lower voltage high current circuit increases the arcing since only lower voltage is needed to sustain or increase the arcing once arcing is established.

Abstract: Disclosed is a distributorless ignition system of inductive discharge type for internal combustion engines. This system comprises basic ignition coil means (14) for centralized supplying of inductive energy for spark plugs and trigger ignition coil means (22a, 22b, 22c and 22d) preferably disposed on spark plug heads for inducing electrical break-down across the electrodes of a spark plug. Both the basic and trigger ignition coil means are energized from a battery (10) through switching means (36a and 36b). The basic ignition coil means generates current pulses for spark plugs with respectively low voltage. The rated power of the trigger ignition coil means is provided to be much less than the same of the basic ignition coil means.

Abstract: A variable cam phase timing system in which there is one crankshaft sensor, and one camshaft sensor per independently phase shiftable camshaft which can be used for controlling the cam phase shifting, sequential fuel control, and also spark timing during both start-up and during run. In addition, the system can control spark timing, without phase shifting, should the crankshaft sensor fail.

Abstract: An ignition system for a spark ignited internal combustion engine has a plurality of high voltage switches connected respectively between a source of spark plug firing voltage and the spark plugs of the engine. Each high voltage switch includes a plurality of series connected light sensitive controlled rectifiers. The controlled rectifiers are associated with light emitting diodes which are positioned to apply light energy to the controlled rectifiers. When light energy is applied to a controlled rectifier, it is biased or gated conductive. The system is arranged such that all of the controlled rectifiers are biased conductive before the spark plug firing voltage is developed. A high voltage switch can be formed by mounting the controlled rectifiers on a substrate. The light emitting diodes are positioned such that the light emitted from one diode is applied to a plurality of controlled rectifiers.

Abstract: To control the ignition of an internal combustion engine the ignition of a spark plug is determined by means of one ignition coil assigned to each spark plug, of a first counter which, on the occurrence of an angle-fixed reference mark, is counted upwards or downwards starting from a predeterminable value by means of an angle-dependent timing signal for triggering the ignition of a spark plug in the internal combustion engine, the spark plug to be fired in each case being determined via a cylinder recognition system. The start of charging of all the ignition coils of the internal combustion engine is initiated by means of a further counting device, the count of which changes the conditioned-by-the-angle-dependent timing signal, and which in each case is assigned a starting value which corresponds to the gap up to the start of charging of the next coil. Thus while the first counting device triggers the ignition process, the second counting device determines when the charging process of an ignition coil begins.

Abstract: An electronic ignition system provides precisely timed spark plug ignition in the combustion chambers of an internal combustion engine and provides an optimal supply of ignition energy for the required operating mode by including a programmable transistor ignition system ("PTI") controllable according to engine operating parameters which can execute a joint program for all spark plugs. The PTI is connected in series with high-voltage capacitor ignition devices associated with the individual spark plugs and supplies ignition energy to them repeatedly during each ignition process.

Abstract: Continued improper and erroneous ignition control resulting from misidentification of reference positions of the cylinders of an internal combustion engine can be prevented in an effective manner. A signal generator generates a reference signal SGT representative of at least one predetermined reference crank angle of each cylinder and a cylinder identification signal SGC. The at least one reference crank angle of each cylinder is successively identified on the basis of the reference signal and the cylinder identification signal. It is evaluated whether the identification of the cylinder reference position is correct. Then, ignition control is performed based on the result of the evaluation. More specifically, ignition control is performed in a timer controlled manner if the cyinder identification is correct.

Abstract: Spark discharge signals monitored on primary windings of ignition coils of a coil per plug (CPP) ignition system are used to identify which cylinder of a cylinder pair is in compression and which cylinder in a cylinder pair is in exhaust. Once determined, the cylinder pair can be tracked such that the primary windings do not need to be monitored further. In one embodiment of the invention, the duration times of substantially simultaneous spark discharge signals in cylinders of a pair of cylinders are compared to one another. The shorter duration time signal indicates the cylinder in the compression cycle. One cylinder pair may be tested two or more times or one or more additional cylinder pairs may be tested to verify cylinder identification. In a second embodiment of the invention, two or more spark dwell signals are applied to the primary windings of the ignition coils for each spark event of a pair of cylinders.

Abstract: An ignition system for an automobile including a spark circuit, a power supply circuit for supplying power, a switching circuit for supplying power from the power supply circuit to the spark circuit, a distributing circuit for controlling the switching circuit in accordance with a ignition timing signal, and a control circuit for receiving the ignition timing signal and for disabling the distributing circuit for a predetermined period of time in response to a value of the received ignition timing signal.

Abstract: This invention provides an ignition system for a spark initiated internal combustion engine such as an Otto cycle engine. High voltage pulses are generated, for instance by way of an ignition coil, and these are passed to the respective spark gaps by way of semiconductor switches. These semiconductor switches are preferably bulk photoconductive switch devices which each comprise a light source and a photosensitive switch. These devices are under the control of control circuitry which activates and deactivates the light sources approximately to distribute the high voltage pulses to the spark plugs. These switches may be used to improve the rise time of the potential across the spark gap or to generate a plurality of sparks in one gap from a single pulse.

Abstract: The ignition unit includes a support housing containing two ignition coils each for the connection to at least one, and preferably two, associated spark plugs. Each ignition coil comprises a primary winding and a second winding disposed around the end arms of a magnetic core or circuit formed by only two packs of plates juxtaposed so that together they form essentially a figure-of-8 shape. The packs of plates are identical, essentially E-shaped and are placed close together, face-to-face, so that together they form a squared figure-of-8 shape. Each of the packs of plates has a notch which extends from the back of the E into its central arm and almost up to the end of the free end thereof. Conveniently, inserts of non-magnetic material are disposed in the notches in the packs of plates.

Abstract: A signal generator generates a crank angle reference signal and a cylinder identification signal in synchronism with the rotation of a multi-cylinder internal combustion engine. The crank angle reference signal has high and low levels which change at a first reference crank position and at a second reference crank position of each cylinder. The cylinder identification signal corresponds to a specific cylinder and is out of phase with respect to the crank angle reference signal. The operating position of each cylinder is determined on the basis of the crank angle reference signal and the cylinder identification signal so that the ignition of each cylinder is controlled based on these signals. The ignition control for the cylinders is stopped if there is an abnormality in the crank angle reference signal or in the cylinder identification signal. This improves reliability and stability in the control of the overall system.

Abstract: The device comprises a primary winding in which the spark energy is stored to be transferred rhythmically to a secondary winding with respective voltage step-up transformers acting between the secondary winding and the spark plugs. An amperometric resistor is arranged in series with the diode through which the current flows when the energy is transferred to the plugs. For each spark, there is a corresponding voltage peak across the terminals of the resistor, whereby a failure to detect the presence of the peak (which is usually converted into a square-wave signal) identifies the absence of a spark.

Abstract: A direct fire ignition system for an internal combustion engine having a coil assembly attachable to each spark plug. Each coil assembly has a high voltage transformer for producing a voltage sufficient to cause the spark plug to generate a spark, an integral capacitor parallel with the spark plug, and a spark plug sensor circuit coupling to the high voltage transformer for generating a spark confirmation signal when a spark is generated. The spark sensor circuit is responsive to a high frequency signal generated in the high voltage transformer within a predetermined frequency range to generate the spark confirmation signal. The direct fire ignition system is compatible with single strike or multi-strike modes of operation. The system can also generate a probe voltage across the spark plug to test for auto or pre-ignition.

Abstract: A high-voltage switch (10), which is usable particularly as an ignition voltage distributor for applying the ignition voltage to spark plugs of an internal combustion engine, comprises a cascade circuit of optoelectronic semiconductor elements (11) which are actuated by means of incident light radiation. A plurality of photo semiconductor elements (11) are controlled by a light-emitting element (12) via a biconvex cylinder lens (30). A distribution of the radiation by means of light guide fibers (37) is also possible. The light-emitting elements (12) which are operated with low voltage can be arranged in a housing (36) separate from the high-voltage side by means of the use of light guides (37), so that a complete galvanic separation is achieved.

Abstract: Methods for associating ignition signals with a reference cylinder in multiple-spark ignition systems of internal combustion engines with externally supplied ignition are proposed; different signal levels for the primary and supporting sparks are used in a first method, and the time offset between the primary and supporting spark onsets is used in a second method for the association.

Abstract: A method of and apparatus for enabling at least one spark plug of a internal combustion engine to provide a fuel igniting spark at a selectable time in the engine cycle is disclosed. Sensors provide a first engine rotation determined pulse train the repetition rate of which is the same as the number of revolutions per second of the engine and a second engine rotation determined pulse train the repetition rate of which is an integral multiple of that of the first pulse train. The reference pulse initiates a count of pulses in the second pulse train and, upon reaching a preselected count, initiates a count of pulses in a third independent pulse train having a much greater repetition rate. The spark plug is enabled when the third pulse train count reaches a preselected count.

Abstract: A distributorless ignition system for an internal combustion engine includes one spark coil for cylinder of the engine, a first reference signal generator for producing a first signal indicative of each revolution of the engine, a second reference signal generator for producing a second signal indicative of every second revolution of the engine, and a processor for evaluating the advance and dwell angles of an ignition pulse to a selected spark coil determined from a logical combination of the first and second signals. During starting, the processor is arranged to operate in a dual-spark mode for the first revolution of the engine and produce two ignition pulses simultaneously for each first signal, one to each of two cylinders which are 360.degree. out of phase with each other. During running of the engine, the second reference signal generator is monitored and, if found to be faulty, the processor changes from a one-spark mode to a dual-spark mode.

Abstract: A tachometer signal generating device comprises signal coils which generate pulse signals corresponding to predetermined crank angle positions in synchronism with revolution of an engine, and a microcomputer which generates ignition control signals or fuel control signals on the basis of the pulse signals and which generates a tachometer signal of 6 pulses/one revolution.

Abstract: A control device for a multi-cylinder engine comprises, in addition to a sensor 11 for detecting reference rotational positions of the crank shaft 1, an ionization current detector 41 for detecting the ionization current across a spark plug 33 of a cylinder. From the output of the sensor 11, the microcomputer 40 discriminates the group of cylinders which are in the compression and the exhaust stroke. For a short period after the start of the engine, the group of cylinders in the compression and the exhaust stroke are ignited simultaneously. During this short period, the cylinder in the compression stroke is discriminated from the group of cylinders in the compression and the exhaust stroke, on the basis of the output of the ionization current detector 41, and the number of succesive discriminations of the cylinder in the compression stroke is counted.

Abstract: A distributorless ignition system using a dual-spark ignition coil generates a signal indicative of which of the two cylinders associated with the dual-spark coil is operating in its power stroke by means of a single detector connected to a predetermined one of the cylinders. The output of the detector is fed to a sample and hold circuit which supplies the peak value from the detector to the control unit of the ignition system where the peak value is evaluated and identified by comparison to a previously obtained peak value. The control unit indicates that the predetermined cylinder is in its power stroke when the detected peak value signal is at its higher level. Conversely, when the peak value signal is at its lower level the control unit determines that it is the other of the two cylinders which is in its lower stroke and signals this accordingly.

Abstract: An ignition timing control system for an engine provides a counter-measure for an abnormal condition of a signal.

Abstract: An apparatus is provided for controlling ignition in an internal combustion engine having N cylinders and a capacitor discharge ignition system. The capacitor discharge system includes an ignition capacitor which is maintained at a predetermined electrical potential by a charging circuit. N transformers are provided, each having a primary coil and a secondary coil. The primary coils include first and second terminals and the secondary coils are electrically connected in parallel with the spark gap in an associated one of the cylinders. Selector switches are connected between the ignition capacitor and an associated one of the primary first terminals. The selector switches are normally biased open and are adapted to close in response to receiving cylinder select signals. The cylinder select signals are produced in response to a desired ignition sequence and for a period of time corresponding to a desired spark duration in an associated cylinder.

Abstract: A method and apparatus is disclosed for controlling the duration of ionization of spark plugs in an internal combustion engine. Generally, the ionization times of the spark plugs are individually measured and compared against a reference ionization time to develop an error signal representing an undesired deviation from the reference ionization time. Then, the duration of current dwell time in the engine's ignition coil is adjusted so as to change ionization time and reduce the size of the error signal.

Abstract: A cylinder recognition apparatus for a multi-cylinder internal combustion engine capable of recognizing a specific reference cylinder as well as the remaining cylinders of the engine by use of only a single signal. A signal generator generates a single output signal in synchrony with the rotation of the engine, the output signal including a plurality of positional pulses each representative of prescribed rotational positions of a corresponding cylinder, and a cylinder recognition pulse at a location near a specific one of the positional pulses corresponding to a specific cylinder. A microcomputer discriminates the cylinder recognition pulse among the signal generator output pulses so as to recognize the specific positional pulse corresponding to the speicfic cylinder.

Abstract: Upon starting or in the event of a malfunction of the sensor for detecting the stage of the engine, the ignition in the various cylinders is controlled according to a sequence different from that used during normal operation. In the case of engines with odd numbers of cylinders, the sequence is completed in a rotation of the driving shaft through 360.degree. and acts on only one cylinder at a time; in the case of engines with even numbers of cylinders, the sequence is completed in a rotation of the driving shaft through 720.degree. and involves a pair of cylinders at a time.

Abstract: This specification discloses an electronic distribution type ignition system wherein at least two ignition coils are provided, and wherein the secondary voltage of the ignition coils is directly supplied to spark plugs. An ignition system according to this invention comprises switching circuits for controlling the supply of a primary voltage to said, ignition coils, a resistance element wherein a current flows selectively which corresponds to a primary current for each of two ignition coils, supplied through two of said switching circuit, current control circuits for detecting a terminal voltage of said resistance element and for controlling, according to said terminal voltage, the primary current flowing through each said igniton coil so as to be at a target value, and a board having said resistance element formed thereon.

Abstract: Fuel is sequentially injected directly into each cylinder of a an engine that has at least three cylinders. Then, an ignition potential is applied to all cylinders simultaneously, but at an angle that ensures that only a selected one of the cylinders experiences combustion. This technique is repeated for each remaining cylinder, so as to fire one cylinder at a time even through an ignition potential is applied to all cylinders simultaneously.

Abstract: A repetitive spark distributorless ignition system stops ignition current before the complete discharge of magnetic energy in the ignition coil supplying the spark plug. The ignition coil is then recharged so an additional spark can be applied to the spark plug.

Abstract: A system and method for controlling ignition timing for an internal combustion engine having cylinder bank rows are disclosed in which the ignition timings for the cylinders belonging to one of the cylinder banks determined according to engine load and engine revolution speed and are corrected according to differences in the ignition timings for the cylinders of both cylinder bank rows so as to eliminate variations in the ignition timings between each cylinder bank row. The crank angle sensor of the ignition timing control system is installed on at least one camshaft for either exhaust or suction valves on an overhead cam at one of the cylinders belonging to either of the cylinder bank rows.

Abstract: The device essentially comprises an auxiliary coil for storing the ignition energy, and a transformer for each spark plug. It is thus possible to prepolarize each transformer in the proper sequence with a current opposite that applied during discharge, whereby a transformer of smaller dimensions can be associated with each spark plug while the performance remains unchanged from that of conventional systems.

Abstract: A crank angle detecting system for a multicylinder engine includes a disc formed with a large number of slits to detect one-degree crank angular positions and a small number of slits to detect a predetermined piston stroke for each cylinder. Since the widths of a small number of slits are different from each other, it is possible to separately discriminate each cylinder in crank angular position on the basis of the crank angle signals obtained by a large number of slits. In the case where the detecting system is incorporated with a group-ignition system, it is possible to detect a predetermined piston stroke for each cylinder immediately after the engine is started, thus preventing the engine from erroneous ignition.