An ignition coil control system may include a first ignition coil including a primary coil and a secondary coil; a first switch that selectively electrically-connects the primary coil of the first ignition coil; a second ignition coil including a primary coil and a secondary coil; a second switch that selectively electrically-connects the primary coil of the second ignition coil; a pair of electrodes generating spark discharge by a discharge current generated in the first ignition coil and the second ignition coil; and an ignition controller that controls spark discharge of the pair of electrodes by adjusting an amount and a duration of the discharge current of the first ignition coil and the second ignition coil by turning the first switch and the second switch on or off according to a single pulse signal having a constant voltage including different voltages transmitted from an engine control unit (ECU).

A switch control circuit controls a switch element connected to a primary coil of an ignition coil in accordance with an ignition signal. The switch element includes a transistor and a protection element connected between a collector and gate of the transistor. The switch control circuit uses a voltage at a gate terminal controlling the transistor or a voltage corresponding to a collector current of the transistor as a detection voltage and generates a status detection signal corresponding to a change in the detection voltage.

Disclosed is an ignition drive module with stable performance and reliable function, which comprises a module signal input end, a voltage input end, a module signal output end, a comparator connected to the module signal input end a maximum dwell timer module connected to the comparator, a logical judgment module connected to the comparator, and an insulated gate bipolar transistor connected to the logical judgment module. The logical judgment module receives signals from the maximum dwell timer module and the comparator to determine whether to activate the insulated gate bipolar transistor. The output end of the insulated gate bipolar transistor is connected to the module signal output end.

Disclosed is an ignition drive module with stable performance and reliable function, which comprises a module signal input end, a voltage input end, a module signal output end, a comparator. One end of the comparator is connected to the module signal input end, and the other end is connected to a comparison resistance R that is grounded. The ignition drive module further comprises a maximum dwell timer module connected to the comparator, a logical judgment module connected to the comparator, and an IGBT module connected to the logical judgment module which receives the signals from the maximum dwell timer module and the comparator to determine whether to activate the IGBT module. The output end of the IGBT module is connected to the module signal output end.

An ignition coil control system may include a first ignition coil including a primary coil and a secondary coil; a first switch that selectively electrically-connects the primary coil of the first ignition coil; a second ignition coil including a primary coil and a secondary coil; a second switch that selectively electrically-connects the primary coil of the second ignition coil; a pair of electrodes generating spark discharge by a discharge current generated in the first ignition coil and the second ignition coil; and an ignition controller that controls spark discharge of the pair of electrodes by adjusting an amount and a duration of the discharge current of the first ignition coil and the second ignition coil by turning the first switch and the second switch on or off according to a single pulse signal having a constant voltage including different voltages transmitted from an engine control unit (ECU).

An ignition coil control system includes: a first ignition coil; a second ignition coil; a spark plug generating spark discharge by a discharge current generated in the first ignition coil and the second ignition coil; and an ignition controller that controls spark discharge of the electrode by adjusting an amount and duration of the discharge current of the first ignition coil and the second ignition coil based on a step pulse signal including different voltages transmitted from an engine control unit (ECU).

An igniter includes a switch element with input, output control electrodes, a first lead in contact with the input electrode and connected to a primary coil of an ignition coil, a second lead that is grounded, a third lead spaced apart from the first and second leads, a first bonding wire connecting the output electrode and the third lead, a second bonding wire connecting the third lead and the second lead, and a control IC that drives the switch element based on an ignition instruction signal from an engine control unit. The control IC generates an ignition confirmation signal based on the voltage of the third lead, and outputs the signal to the engine control unit.

Provided is an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more advanced when an in-cylinder temperature specified by an in-cylinder temperature specification section is high than when the in-cylinder temperature is low.

Provided is an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more advanced when an in-cylinder temperature specified by an in-cylinder temperature specification section is high than when the in-cylinder temperature is low.

The subject matter of this specification can be embodied in, among other things, a method that includes receiving a collection of measurements of electric current amplitude in a primary winding of an engine ignition system having the primary winding and a spark plug, identifying an ignition start time, identifying an inflection point based on the plurality of measurements, determining an inflection point time representative of a time at which the identified inflection point occurred, determining a spark start time based on an amount of time between the ignition start time and the inflection point time, and providing a signal indicative of the spark start time.