In an implementation, a method of operating an ignition circuit can include enabling a charge path control circuit and a switch circuit to charge a primary winding of an ignition coil of the ignition circuit until a threshold current is reached in the primary winding. After reaching the threshold current in the primary winding, the method can include maintaining a current in the primary winding of the ignition coil in correspondence with a current limit by alternatively activating and deactivating the charge path control circuit complementary to alternative activation and deactivation of a circulating-current path control circuit. During the maintaining the current in the primary winding, the method can include initiating a spark in a spark plug included in the ignition circuit, the initiating the spark including controlling an amount of energy delivered from the primary winding to a secondary winding of the ignition coil.

An embodiment system for controlling an ignition coil includes a first ignition coil including a first primary coil and a first secondary coil, a second ignition coil including a second primary coil and a second secondary coil, a spark plug including a pair of electrodes configured to generate a spark discharge by a discharge current generated by the first ignition coil and the second ignition coil, and a controller configured to selectively perform a multi-stage ignition through the first ignition coil and the second ignition coil or a single-stage ignition through the first ignition coil or the second ignition coil depending on an operation region of an engine and, in response to a misfire occurring in the engine while performing the multi-stage ignition, to adjust a number of ignitions or a dwell time.

In an internal combustion engine which performs a homogeneous lean combustion mode and a stratified lean combustion mode, there is provided a new internal combustion engine control device capable of obtaining a stable combustion state by decreasing influences of delay of an air flow and a degree of change of a transient state and smoothly performing switching between the homogeneous lean combustion mode and the stratified lean combustion mode. Accordingly, in the present invention, when switching between the stratified lean mode in which a compression stroke injection is performed by a direct injection injector 7 and the homogeneous lean combustion mode in which an intake stroke injection is performed by the direct injection injector 7 is performed, a predetermined delay time t is provided from at least a switching operation of a tumble control valve 6, a switching operation between the compression stroke injection and the intake stroke injection is performed, and the delay time t is set so as to correspond to a magnitude of the degree of change L of the transient state. A switching timing between the compression stroke injection and the intake stroke injection is controlled according to the flow delay of an air control system such as the tumble control valve 6 and the degree of change L of the transient state, and thus, it is possible to improve combustion stability in a combustion chamber.

A drive circuit that operates stably and has a small circuit size. Provided is a switch apparatus including a power semiconductor element connected between a first terminal on a high potential side and a second terminal on a low potential side; a capacitor; a charging section that charges the capacitor for at least a portion of an interval during which the power semiconductor element is OFF; a discharging section that causes the capacitor to gradually discharge, in response to the power semiconductor element becoming ON; and a cutoff section that sets the power semiconductor element to an OFF state, in response to a voltage of the capacitor becoming lower than a threshold voltage.

An ignition control system performs discharge generation control, in which a discharge spark is generated, once or a plurality of times during a single combustion cycle. The ignition control system successively calculates an approximate energy density based on a secondary current and a discharge path length. During a predetermined period after blocking of a primary current is performed during a single combustion cycle, the ignition control system calculates an integrated value by integrating the discharge path length at this time, based on the approximate energy density being greater than a predetermined value. The ignition control system performs the discharge generation control again based on the calculated integrated value being less than a first threshold.

Various embodiments of the present technology comprise a method and apparatus for an ignition system. In various embodiments, the ignition system activates a soft shutdown of an ignition coil in the event of an over dwell condition. The apparatus comprises first and second voltage-to-current converters and utilizes a difference of the converter outputs to control the current through the ignition coil. During the soft shutdown, the current decreases non-linearly during a first period and decreases linearly during an immediately following second period.

A controller for a spark plug of an engine is provided. The controller is configured to receive a signal indicative of an operational parameter of the engine. The controller is configured to define a breakdown time duration for the spark plug. Further, the controller is configured to determine an optimum amount of energy required to generate a spark for the spark plug based on the defined breakdown time duration and the operational parameter. The controller is further configured to cause the optimum amount of energy to be supplied to the spark plug to cause the spark to be generated for the spark plug.

An ignition coil control system includes: a plurality of ignition coils that respectively include a primary coil and a secondary coil; a spark plug that generates a spark discharge by a discharge current generated by the plurality of ignition coils and that includes a center electrode and a ground electrode; a sensing part measuring a current applied to the primary coil; and an ignition controller that adjusts a reference duty signal based on an amount of the current applied to the primary coil sensed by the sensing part to adjust discharge energy generated between the center electrode and the ground electrode through the secondary coil.

An electronic ignition system for an internal combustion engine comprises an ignition coil (2) provided with at least a primary winding (3) and a secondary winding (4), a switch (6) connected to the primary winding (3) and drivable in an open and/or closed position according to the value of a driving signal, a control unit (7) associated to the switch (6) and configured to drive it in open and/or closed position according to the value of the driving signal (G). Such system also comprises a voltage changing electronic element (8) connected to the electrical connection (5), operatively interposed between the electrical connection (5) and the primary winding (3), and configured to change the voltage value of the primary winding (3) according to the value of a control signal between at least a first (V1) and a second (V2) voltage value. The system also comprises a ionization measuring device (20) around said discharge gap (100a) of the spark plug (100) associated with the secondary winding (4) and arranged to detect a current value in the secondary winding (4) and to send a signal representative of said value to the control unit (7), wherein the control unit (7) is configured to activate said measuring device (20) upon the shutdown of the electric arc or spark.

A combustion control apparatus for an internal combustion engine includes a spark plug for performing spark ignition of an air-fuel mixture in the combustion chamber, a plurality of coil pairs for generating spark discharge in the spark plug, and a fuel injection valve capable of injecting atomized fuel. Atomized fuel is injected into the intake passage, and a homogeneous lean air-fuel mixture is formed in the combustion chamber. The air-fuel ratio of the air-fuel mixture in the combustion chamber is controlled to be leaner than a predetermined lean air-fuel ratio. A spark discharge start timing and a spark discharge continuation time period are controlled using the plurality of coil pairs. The spark discharge start timing is set to a timing advanced from the spark discharge start timing for igniting a stratified lean mixture, such that the air-fuel ratio in the vicinity of the spark plug is relatively small.