Abstract: In an ignition semiconductor device, a self-shut down circuit forcibly turns off an IGBT when an input signal is continuously applied. The self-shut down circuit is formed of a main-current gradual-reduction circuit having a timer circuit, a capacitor, a resistor, and an FET. When the timer circuit, which is actuated when the input signal is input, counts out, the FET is turned on to cause a capacitor, which is connected parallel to a resistor for producing a reference voltage for a current-limiting circuit, to discharge slowly through the resistor, thereby gradually reducing the reference voltage. Correspondingly, the current-limiting circuit reduces the main current to turn off the IGBT. The slow turn-off operation of the IGBT prevents a high voltage from being generated in the ignition coil.

Abstract: An ignition apparatus for an internal combustion engine has an arrangement comprising a power part and a control part which are accumulated in a one-chip in an IGBT monolithic silicon substrate. The control circuit part has current limiting function of prevent the flowing of any current which is above a predetermined value as well as function of detecting malfunction heat generation by which a primary electric current is blocked compulsorily. The secondary voltage of an ignition coil is generated repeatedly below a plug discharge voltage so as not to generate spark discharge in the sparking plug when the electric current compulsory blocking is carried out, and energy charged in the ignition coil is emitted or discharged. With this arrangement, the one-chip ignition apparatus with high reliability can be achieved.

Abstract: A method and an arrangement for energy control on an ignition system for an internal combustion engine are presented having an ignition coil or an ignition transformer whose primary winding can be short circuited by means of a switch, called a short-circuit switch, the ignition coil forming the ignition voltage and having a primary winding and a secondary winding, and, an ion current can be measured with the secondary winding of the ignition coil by means of one or several spark plugs, the primary current in the short-circuit phase of the short-circuit switch is detected with a suitable means and is transmitted to the control unit, the measurement quantity is processed in the form of a function or filtering in the control unit after actuation of the short-circuit switch and an energy control via closure time or closure angle is built up with the obtained feature.

Abstract: A mesh structure portion is provided at a part of a stripe structure IGBT chip, gate resistance of a respective minute IGBT is reduced and in a gate portion chip a filter is constituted by a resistor and a condenser. Under a severe environment such as an integrated ignition coil, a small size and a low cost ignitor which can use without a necessity for a protection circuit by a peripheral circuit can be provided. An ignition apparatus having IGBT which is strong against serge resistant performance and noise resistant performance can be obtained.

Abstract: A current on the primary side of an ignition coil is subjected to repeated conduction/cutoff control in accordance with an ignition control signal of an ECU to thereby generate a high voltage for ignition twice or more in one combustion stroke. In such a multiple ignition system for an internal combustion engine, the primary current of the ignition coil is detected by a resistor to thereby make the ECU recognize the fact that the primary current has reached a value not smaller than a set value through a signal line when the primary current becomes not smaller than the set value. The ECU determines cutoff timing in the second-time et seq. in the repeated conduction/cutoff control on the basis of the recognition.

Abstract: An ignition system, of the type having ignition coils supplying energy to spark plugs in an internal combustion engine, includes apparatus to measure an electrical characteristic indicative of spark duration and generate a representative spark duration signal therefrom, or alternately to directly measure spark duration and generate a representative spark duration signal. Computational circuitry receives the spark duration signal and a spark duration setpoint signal, computes the error between the setpoint and the actual spark duration on a real-time basis, and modulates the energy in the high energy power supply to the ignition coils for maintaining a constant spark duration.

Abstract: An apparatus is described for regulating the flow of current through a load in which the flow of current is monitored in the form of a reference voltage by an analog input and a digital input of an arithmetic and logic unit. The voltage measured at the analog input is used to regulate the flow of current. The voltage measured at the digital input either as a low or as a high signal is used to switch off the flow of current when there is a low signal.

Abstract: The diagnosis of an open-circuit fault or of a short-circuit in an ignition system is effected by performing asynchronous periodic extraction of samples of current in a switch. A check is made to ensure the satisfaction of certain temporal conditions in respect to a moment of extraction of the samples and comparing the samples, on the basis of that the temporal conditions are satisfied, with predetermined fault threshold values.

Abstract: An ignition control system for an internal combustion engine includes a control circuit, an ignition coil, a switch, and a sensing circuit. The control circuit is configured to interrupt a primary current, thereby establishing a secondary current which is discharged to cause a spark plug coupled to the secondary winding to produce a first spark. The sensing circuit is configured to generate a secondary current signal representative of a level of secondary current. The control circuit is responsive to the secondary current signal to terminate the discharge by closing the switch to cause the primary current to again flow in preparation of a second spark. The termination of the discharge occurs when the secondary current level reaches a secondary current threshold which is determined as a function of engine speed and ambient temperature.

Abstract: An electric ignition device for an internal combustion engine having a primary and a secondary circuit coupled together by a transformer. The secondary circuit includes a spark gap. The primary circuit includes a capacitor that can be discharged. The voltage discharged by the capacitor is coupled by the transformer to the secondary circuit where it produces an ignition spark across the spark gap. The primary circuit is a resonant circuit that is repeatedly excited keeping the ignition spark burning as an arc. Current or voltage in the secondary circuit are detected to control the energy introduced into the spark gap.

Abstract: In order to reduce the bulk and weight of the upper igniter case division of the armor case, and to lower the center of gravity of the total apparatus so as to provide an igniter which is tough to oscillate, the igniter for the internal combustion engine has the armor case equipped with the coil department and igniter unit therein, and said armor case has the igniter case having the coil department case and the connector department. Furthermore, the coil department case is inserted in the plug hole of the internal combustion engine. The igniter unit is mounted in the igniter case. Furthermore, the igniter unit has a semiconductor device of a simple substance silicon chip having integrated therein a semi-conductor for switching and a current limiting circuitry. The semi-conductor for switching consists of an insulated bipolar transistor (IGBT) or a power transistor.

Abstract: A resonance transducer ignition system for an engine includes a voltage source, a semiconductor circuit-breaker, a resonance capacitance, an energy recovery diode, an open- and closed-loop control unit, a spark plug and an ignition transformer. The resonance capacitance is part of a first resonant circuit. A second resonant circuit is composed of a secondary capacitance. The secondary capacitance is composed of a spark plug capacitance and a stray capacitance. The two resonant circuits are coupled to one another via the ignition transformer, the coupling coefficient, k, being >0.65.

Abstract: An ignition system for internal combustion engines with spark ignition comprising an ignition coil, a spark plug connected to the secondary winding, an electric supply circuit associated with the primary winding of the coil, where the said circuit includes a semiconductor device controlled by an electronic control unit programmed to produce a charging cycle in the course of which the instantaneous current flowing in the primary winding gradually increases from a minimum value to a maximum value and then returns brusquely to the minimum value. The electronic control unit is programmed to produce a succession of charging cycles during one and the same engine cycle. Each of the said charging cycles is separated from the previous cycle by a time interval (W) of a duration that is either equal to or greater than the duration (DA) of a discharge cycle.

Abstract: A combustion engine comprises at least two combustion chambers and an ignition system having a spark device (11, 13) forming an electrode gap and a charging member (20) for accumulating the electrical energy necessary for generating a spark in the electrode gap. The combustion chambers are in the compression stroke according to a predetermined sequence. During a first engine revolution, high voltage pulses are supplied at a high frequency to all spark devices (11, 13). The spark voltage in the electrode gap of each spark device (11, 13) is measured for each spark. Based on the measured spark voltage of the different spark devices, the combustion chamber that first will be in the compression stroke is determined by means of an electronic control unit (3). Based on the predetermined sequence and the knowledge of the combustion chamber that first is in the compression stroke, fuel is injected in the combustion chamber that next will be in the compression stroke.

Abstract: A circuit is provided in which a voltage due to a minute current is applied to a gate terminal from a collector terminal when a collector voltage is higher than a gate voltage in an operation of current limitation. Thus, an increase in the collector voltage immediately after the operation of current limitation starts serves to boost the gate voltage. The boosted voltage suppress an abrupt increase in the collector voltage. When the collector voltage is reduced by oscillation, the action of boosting the gate voltage is lowered to suppress the reduction of the collector voltage.

Abstract: According to the invention, a primary winding of an ignition coil is coupled with an insulated-gate bipolar transistor (IGBT). The IGBT is controlled by a current restriction circuit, which includes a control transistor for performing the on-off operation of the IGBT such that the IGBT is made conductive upon occurrence of an ignition control signal, and nonconductive, when a primary current of the ignition coil reaches a certain value depending on a reference voltage determined by a bias circuit. The bias circuit has a condenser, which is charged by a base current of the control transistor to change the base potential of the transistor slowly, when the transistor is made nonconductive.

Abstract: In order to reduce the bulk and weight of the upper igniter case division of an armor case, and to lower the center of gravity of the total apparatus so as to provide an igniter which is tough to oscillate, the igniter for the internal combustion engine has the armor case equipped with a coil compartment and igniter unit. The armor case has the igniter case having the coil case and connector. Furthermore, the coil compartment case is inserted in the plug hole of the internal combustion engine. The igniter unit is mounted in the igniter case. Furthermore, the igniter unit has a semiconductor device of a single substance silicon chip having integrated therein a semi-conductor for switching and a current limiting circuitry. The semi-conductor for switching consists of an insulated bipolar transistor (IGBT) or a power transistor.

Abstract: An apparatus controls an ignition timing in association with rotation of an engine. The engine has an ignitor, an ignition coil and a spark plug. The ignitor provides the ignition coil with primary current to actuate the ignition coil. The ignition coil provides the spark plug with secondary current to actuate the spark plug when the primary current is cut off. A sensor detects the rotation of the engine by a predetermined angle and outputs a first signal based on the detection. An electronic control unit (ECU) computes an ignition timing of the ignition coil based on the first signal and driving state of the engine. The ECU outputs a second signal to the ignitor to control the primary current provided to the ignition coil. The ECU prohibits a provision of the primary current to the ignition coil when the primary current is provided to the ignition coil for a first predetermined time period.

Abstract: An alternating current ignition system which can be used in one of two ways for ion current measurement. On the one hand, an oscillating circuit at the primary end of the ignition coil can be driven such that, after ignition has taken place, an alternating current signal is generated at the primary end; the amplitude of the alternating current signal must be sufficiently low so as not to cause any sparks at the secondary end, but lead to an alternating voltage signal which is modulated in relation to the ionisation degree of the ignition spark gap and thus represents an ion current measurement signal. On the other hand, however, if an auto transformer is used as an ignition coil, the intermediate circuit voltage applying at the primary end will be modulated in the medium-high voltage range of, e.g, 180 V in relation to the degree of ionisation, so that this supply voltage is used as a measurement signal.

Abstract: An igniter for an internal combustion engine includes a switching element performing flow and break control for a primary current flowing through an ignition coil depending upon a spark control signal output from an electronic engine control unit and a current limiting circuit limiting a current flowing through the switching element. The switching element is formed with an insulated gate bipolar transistor. The igniter further comprises a current detecting load element for detecting current flowing through the insulated gate bipolar transistor, and a diode being provided between the current detecting load element and the self-isolation N-MOS transistor, which diode having an opposite temperature coefficient to that of the current detecting load element.

Abstract: An electronic ignition system for an internal combustion engine is so controlled that an ignition current or secondary current caused by an ignition spark at the respective spark plug in the secondary coil of an ignition transformer is evaluated for initiating, if necessary, follow-up charges of the primary coil to thereby generate further ignition impulses. The initial loading or charging impulse is provided by a respective control circuit. The total sparking time at the respective spark plug thus corresponds to a sequence of individual impulses, each of which causes an ignition spark. The detection of the ignition current in the secondary coils is performed with an ignition current measuring circuit arrangement connected to the secondary coils. This measuring circuit (SC) generates a signal representing the secondary or ignition current represented as a voltage drop across a measuring resistor (R.sub.2).

Abstract: A circuit for use with an ignition system to enable detection of an overvoltage condition in the primary winding of an ignition coil caused by opening of a power switch connected to the primary winding. The circuit senses the overvoltage condition by comparing the voltage on the primary winding to a first threshold voltage and produces a signal at an output terminal indicative of the presence of the overvoltage condition. The output terminal is maintained at a high logic level upon detection of an overvoltage condition and throughout the time duration of the overvoltage condition, and drops to a low logic level when the voltage on the primary winding falls to a second threshold voltage, which is lower than the first threshold voltage. Comparison circuitry is provided for sensing the overvoltage condition by reference to fixed voltage values. Logic circuitry responds to the comparison circuitry to produce the appropriate logic levels at the output terminal.

Abstract: An ignition device for an internal combustion engine in which an iron coil is easily and securely grounded. In the ignition device, an ignition coil includes an iron core formed by laminating a plurality of cut steel plates; a primary coil wound around the iron core; a secondary coil wound around the primary coil; and a conductive plate being arranged between the iron core and a primary bobbin of the primary coil, having a contact surface with which sections of the steel plates are in contact and being electrically connected to a ground terminal of an external terminal.

Abstract: An ignition circuit IG converts a battery voltage into a high spark plug discharge voltage. A resistor R1 inserted into the power supply path L detects the current flowing through the ignition circuit by converting the current into a voltage, and a level shift circuit LS shifts the potential level at both terminals of the detection resistor. A level deviation detection circuit regulates the level of a deviation voltage developed across the detection resistor, which is caused when an electric current flows from the battery to the ignition circuit, and outputs the deviation voltage. A reference voltage generation portion sets a reference voltage to be compared with the deviation voltage by a comparator COM. A clamping circuit CL suppresses variations in the power supply voltage corresponding to the level deviation detection circuit and the comparator, and protects the level deviation detection circuit.

Abstract: An ignition coil control circuit for controlling a current flowing to a primary coil of an ignition coil, comprises a switching circuit for switching the primary coil of the ignition coil, a driving circuit for driving the switching circuit, a control signal output circuit for generating and outputting a driving control signal to the driving circuit in accordance with a signal from an ECU, and a current limiting circuit for detecting a value of the current fed to the primary coil by the switching circuit and controlling the switching circuit to make the current value not larger than a predetermined value and wherein the control signal output circuit uses the signal from the ECU as its power source, and the current limiting circuit uses a switching driving signal output from the driving circuit for driving the switching circuit as its power source.

Abstract: A respective power semiconductor switch (M1, M2, M3) is provided for each ignition coil (20) of an internal combustion engine. Each such switch (M1, M2, M3) has a first main electrode (C) for coupling the primary winding (20a) of the associated ignition coil (20) to a first voltage supply line (1), and a control electrode (G) coupled to an respective ignition control line (Ign1, Ign2, Ign3) for rendering these switches (M1, M2, M3) conducting in a given sequence. A further semiconductor device (M4) has first and second main electrodes (d and s) coupled between second main electrodes (E) of the power semiconductor switches (M1, M2, M3) and a second voltage supply line (2), and a control electrode (g) for a drive signal controlling the current flow through the device (M4). A current sensing arrangement (Rs) senses the current flowing through this further device (M4).

Abstract: A method is proposed for monitoring operations of an internal combustion engine to detect combustion misses for internal combustion engines having dual spark coils. A method is provided for the primary-side monitoring of the spark voltage and/or of the spark duration, and a method is provided for detecting irregular operations. If a faulty ignition is detected in one cylinder at one spark plug by monitoring the spark voltage and/or the spark duration, the second spark plug in this cylinder is then cut off (de-energized) and the reaction to this cut-off is monitored by means of the method for detecting irregular running. If the irregular running detection confirms faulty operation of the internal combustion engine, then the faulty ignition at the first spark plug of a cylinder was correctly recognized and appropriate emergency measures are introduced.

Abstract: An IGBT driving circuit includes an IGBT connected in series with a primary winding of an ignition coil and a current detecting resistor. A transistor is connected to the gate of the IGBT to apply a gate voltage in response to an ignition signal. A comparator compares a voltage produced across the current detecting resistor with a comparison voltage. An NPN transistor connected to the gate of the IGBT turns on and off in response to the comparison result of the comparator to adjust the gate voltage. The gate voltage is fed back to the detection terminal side of the comparator for oscillation suppression through an oscillation suppressing resistor. A charge/discharge control resistor is connected between the gate of the IGBT and the oscillation suppressing resistor and a diode is connected in parallel with the charge/discharge control resistor, so that the electric current flowing to the IGBT is maintained constant.

Abstract: In an ignition apparatus for an internal combustion engine, an ECU produces an ignition signal to an igniter/coil circuit with an igniter and ignition coil, which in turn sends back a monitor signal for ignition failure determination in the ECU. The ignition signal and the monitor signal are sent through a single signal line. The monitor signal is produced based on a primary current or a secondary current of the ignition coil.

Abstract: In an engine and associated ignition energy and breakdown voltage circuit, the engine having at least one spark plug and an associated ignition coil having a primary and secondary winding, the secondary winding in communication with at least one spark plug. The ignition energy and breakdown voltage circuit comprising the ability to sense an arcing current generated by the spark plug, and also includes the ability for probing a spark plug breakdown voltage. A multiplier is provided for multiplying the spark plug arcing current by the arcing voltage and thereby producing a power signal. The ability to store the breakdown voltage of the spark plug for a period of time is provided, and further the ability to produce an energy signal in proportional representation of an amount of energy delivered to the spark plug. A method is also provided for adaptively changing spark plug energy in response to feedback from the ignition energy circuit.

Abstract: An ignition system for internal combustion engines is provided which has a control device (7) for triggering a sequential spark ignition, which measures the primary current (I.sub.p) of each individual ignition of said sequential spark ignition upon the reconnecting of the flow of current, and which compares it with a reference value. The result of this comparison makes predictions possible concerning the conditions in the combustion chamber, and action, e.g. , increasing the primary disconnection current, can be taken by the control device so that for example any shunts which, are present can be eliminated.

Abstract: An ignition system for internal combustion engines with sequential spark ignition is provided which serves to ensure that the last individual spark (EZ) of a sequential spark ignition does not lead to damage to the internal combustion engine, for instance damage caused by ignition during the exhaust stroke. A closing time corresponding to a charging process (AL) for an individual ignition is subtracted from a distribution limit (VG) to obtain a calculated limit (11). Once this limit is reached, the current charging process proceeds unimpeded to trigger the individual ignition, but no new charging process will be started.

Abstract: An ignition system for internal combustion engines serves as a bracket circuit arrangement (10, 11, 12, 16) to limit the primary voltage, in order to protect parts energized with high voltage from being destroyed. The ignition system comprises a voltage bracketing of the ignition transistor (3), the bracketing voltage being variable in dependence upon a secondary-side load. The primary voltage (U.sub.P) is acquired by an evaluation unit (9) and, given a high secondary load, a high bracketing voltage is used and, given a low secondary load, a low bracketing voltage is used.

Abstract: The ignition system for a four-cycle gasoline engine having at least one cylinder includes a spark plug for each cylinder and an ignition coil for each spark plug so that each spark plug has its own ignition coil with a primary and secondary side as well as a control device for controlling the timing of the firing of the spark plugs via the individual ignition coils according to a predetermined firing sequence connected to each of the ignition coils.

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: A misfire-detecting system for an internal combustion engine detects a value of the sparking voltage generated by the igniting device after generation of the ignition command signal, determines the duration of a discharge of a spark plug, based upon the detected sparking voltage, and determines whether or not a misfire has occurred in the engine, based upon the determined duration of the discharge. For example, the misfire-detecting system measures the duration of the discharge from the time of generation of the ignition command signal, based upon the detected sparking voltage, compares the measured duration of the discharge with a predetermined time period. When the measured duration is shorter than the predetermined time period, it is determined that a misfire has occurred in the engine.

Abstract: The present invention encompasses an ignition system with an ignition dwell signal (207) having charge and discharge states for driving at least one energy storage device (105) and at least one spark plug (103). This system applies an essentially periodic switching device (107, 209, 211, 215) for discharging excess energy in the energy storage device (105).

Abstract: An ignition device for a multi-cylinder engine includes a plurality of integral ignition device units 9A and 9B associated with respective cylinders. A single ignition detector circuit 8, inserted between the battery 1 and the primary coil of the ignition coil 5 of respective units 9A and 9B, generates an ignition confirmation signal upon detecting a current exceeding a predetermined level.

Abstract: A device for generating a trigger signal from ignition pulses of an ignition system, in which each one of the ignition pulses occurring in the ignition system is represented regardless of whether the ignition process is suppressed or not. The device can be connected to an ignition system which has at least one ignition coil with a primary winding and at least one secondary winding, where the first terminal of the primary winding is connected to the first terminal of a voltage source and the second terminal of the primary winding is connected by means of a controllable switch with a second terminal of the voltage source.

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: The ignition performance monitoring method and apparatus determines the time period during which the current generated in the primary winding of an ignition coil by a pulse from a capacitive discharge ignition system takes the decay to a zero ampere level and uses this determined period to calculate and indicate the firing voltage required to fire a spark plug. The apparatus includes a current sensor connected to sense the current in the primary winding of the ignition coil and a comparator to compare the sensed current with a reference indicative of a zero ampere current level. The comparator provides an output signal having a pulse width indicative of the time the sensed current was above the zero ampere level to a processor which uses the output signal and data values unique to the ignition coil employed to determine a firing voltage for a spark plug fired by the ignition coil.

Abstract: An igniter for an internal combustion engine comprising a power transistor (4), a current regulating circuit (7) and a current detection resistor (12) connected between the power transistor (4) and the ground for detecting the current flowing through an ignition coil. The current detection resistor (12) is trimmed to provide a controlled resistance between the power transistor (4) and the ground. The current detection resistor (12) may be disposed within or outside the mold resin package (10) for hermetically sealing the power transistor (4) and the current regulating circuit (7).

Abstract: An ignition current conduction time control apparatus, comprising power transistors for producing a spark for ignition at the ignition plugs, and a controller for applying ignition signals to the power transistors, wherein the saturated state of the power transistors is eliminated by controlling the start time of current conduction time of said ignition signals applied to the power transistors according to the internal resistance values of the ignition coils, thereby eliminating the heat generation of the ignition coils.

Abstract: A current limiter in an ignition apparatus for an internal combustion engine including a differential amplifier 20 is able to limit a primary winding current of an ignition coil to a prescribed limit value which is independent of a voltage as sensed by a current sensing resistor 11, thus providing a highly stable operating characteristic. The factor of current amplification of the differential amplifier can be increased without accompanying oscillations of the current limiter. The current sensing resistor senses a voltage corresponding to a current flowing from the primary winding of the ignition coil to a power transistor 4 which turns on and off the power supply to the ignition coil. A reference voltage source 12 generates a reference voltage for comparison with the voltage sensed by the current sensing resistor.

Abstract: An ignition system has a plurality of primary and secondary coils, ignition timing means for providing an ignition timing signal and current supply means for supplying a current to the primary coils in response to an ignition timing signal. A current is supplied to a plurality of the primary coils at the same time to charge the coils so that a charge time is shortened.

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 coil unit comprising within an electrically insulating casing (31) an ignition coil (A) and a packaged power switch circuit (E). The packaged power switch circuit (E), which comprises a plurality of electric and electronic components (F) hermetically sealed within a mold resin (G) to form a single compact unitary piece, is disposed within a power switch cavity (31d) of the casing (31). An aluminum heat dissipating plate (30) may be attached at its first end (30a) to said packaged power switch circuit (E) in a thermally conductive relationship and exposed at its second end (30b) to the exterior of said casing (31).

Abstract: An ignition apparatus for an internal combustion engine includes a current limiter for limiting a current supplied from a power source to an ignition coil to a predetermined maximum value irrespective of temperature variations. A current sensing resistor is connected between the power transistor and ground for sensing the magnitude of a primary winding current. A first constant current supply is connected at one end thereof to the base of the power transistor and at the other end to one end of the current sensing resistor through a first transistor. A second constant current supply is connected at one end thereof to the base of the power transistor and at the other end to the other end of the current sensing resistor through a second transistor.

Abstract: A snowmobile electrical system having a battery conservation circuit. The system is designed to conserve battery power after deactivation of the engine using the kill switch, even if the key switch is left on. Battery power is normally consumed by continued connection of the microprocessor-based electronic engine control unit (ECU) to the battery after kill switch activation. To prevent battery consumption, the ECU monitors the electrical output of the ignition system at a position within the system wherein the output is dependent on engine speed. If the output drops to a specified level, a signal generator in the ECU is activated. Signals from the signal generator are directed to a solid state switching system which disconnects the battery from the ECU. As a result, battery consumption is controlled.