An ignition coil control system may include first and second ignition coils, and a spark plug including a pair of electrodes in which generates spark discharge by discharge currents of the first ignition coil and the second ignition coil, a DC-DC converter connected to a primary coil of the first ignition coil, a primary coil of the second ignition coil and a battery; in which converts current magnitude supplied to a primary coil of the first ignition coil and a primary coil of the second ignition coil from a battery, and a controller in which controls the spark discharge of the electrodes by adjusting an amount and a duration of the discharge current of the first ignition coil and the second ignition coil base on a pulse signal, wherein the controller is configured to selectively execute a multi-state ignition through the first ignition coil and the second ignition coil and a single-stage ignition through one of the first ignition coil and the second ignition coil according to an operation region of an engine.

An ignition device for an internal combustion engine includes a switching circuit and a control circuit. The control circuit monitors a voltage level inputted to a switching device which is installed in the switching circuit and connected to a primary winding of an ignition coil. The control circuit includes an overvoltage protection circuit which outputs an energization inhibit signal to inhibit energization of the switching device when the monitored voltage level is higher than an overvoltage threshold level. When the monitored voltage level exceeds the overvoltage threshold level in an output duration in which the energization control signal is outputted, the overvoltage protection circuit stops output of the energization inhibit signal until the output duration expires. This enables the switching device to be protected from damage and an ignition operation to be executed at a correct timing to eliminate a risk of damage to the internal combustion engine.

The invention relates to a device for controlling a multiple spark operation of an internal combustion engine, wherein an ignition transformer can be switched off and back on again for delivering or interrupting an ignition spark energy based on at least one current threshold. The invention proposes that the at least one current threshold be programmable.

The internal combustion engine ignition device has a core, a coil part that is wound over the core, and a secondary coil that is wound on the outer peripheral side of the coil part. A switching element switches an induced current, which is generated via the rotation of a permanent magnet, of a primary coil on and off. A resistor and a microcomputer are connected to the switching element, and a rotation detection circuit is connected to the microcomputer. The microcomputer drives the switching element so as to rapidly change the current flowing through the primary coil and generate a high voltage in the secondary coil, and generate a spark discharge in a spark plug connected to the secondary coil. In the coil part, one coil is divided by an intermediate tap, forming the primary coil and a charging coil.

An ignition apparatus includes a spark plug having a high voltage electrode and an external electrode facing each other across a gap and being configured to generate a spark discharge in the gap to ignite a combustible fuel mixture in a combustion chamber of an internal combustion engine, an ignition coil device configured to generate a predetermined high voltage and supply the high voltage to the high voltage electrode to form a path for the spark discharge in the gap, a high frequency power supply having a band-pass filter and being configured to supply an alternating current to the spark discharge path, and a control device configured to control operation timing of the high frequency power supply. The band-pass filter passes a frequency of from 1 MHz to 4 MHz.

An ignition device for an internal combustion engine includes a switching circuit and a control circuit. The control circuit monitors a voltage level inputted to a switching device which is installed in the switching circuit and connected to a primary winding of an ignition coil. The control circuit includes an overvoltage protection circuit which outputs an energization inhibit signal to inhibit energization of the switching device when the monitored voltage level is higher than an overvoltage threshold level. When the monitored voltage level exceeds the overvoltage threshold level in an output duration in which the energization control signal is outputted, the overvoltage protection circuit stops output of the energization inhibit signal until the output duration expires. This enables the switching device to be protected from damage and an ignition operation to be executed at a correct timing to eliminate a risk of damage to the internal combustion engine.

In an ignition apparatus, a deterioration determination circuit performs a deterioration determination task of (i) monitoring an absolute increase in a temperature parameter during a predetermined deterioration detection period that has been started since an energization command signal being inputted to a control circuit, and (ii) performing a comparison between the absolute increase in the temperature parameter and a predetermined deterioration detection threshold to thereby determine whether a level of deterioration of a switching circuit is within an acceptable level.

An internal combustion engine ignition device includes an ignition coil, an ignition plug, a main ignition circuit, and an energy input circuit. A first switching element of the main ignition circuit performs energization and interruption of energization to a first coil part of a primary coil to generate an induced electromotive force using a DC voltage. A second switching element of the energy input circuit performs energization and interruption of energization to a second coil part of the primary coil to keep a discharge current in a secondary coil within an intended range directly using the DC voltage, after the induced electromotive force has been generated. A soft-off circuit of the energy input circuit slows a turn-off speed of the second switching element. The energy input circuit is configured to, when decreasing a signal voltage added to a gate of the second switching element, execute a first decreasing stage of decreasing the signal voltage until it reaches the vicinity of a gate-source threshold voltage and a second decreasing stage of gradually decreasing the signal voltage in the vicinity of the threshold voltage.

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.

An ignition apparatus for internal combustion engine includes an ignition coil in which a main primary coil and an auxiliary primary coil are magnetically coupled with a secondary coil that is connected to a spark plug. In the ignition apparatus, a main ignition circuit unit controls energization of the main primary coil and performs a main ignition operation in which a spark discharge is generated in the spark plug. An energy supply circuit unit controls energization of the auxiliary primary coil and performs an energy supply operation in which a current that has the same polarity as a secondary current that flows through the secondary coil as a result of the main ignition operation is superimposed on the secondary current. The auxiliary primary coil includes a plurality of auxiliary-primary-coil portions. The energy supply circuit unit performs the energy supply operation using one or more of the plurality of auxiliary-primary-coil portions.