An ignition apparatus for an internal combustion engine includes: a spark plug; a first ignition coil and a second ignition coil; a battery; a booster circuit that boosts a voltage supplied from the battery; a power transistor that conducts and interrupts a primary current flowing to a primary coil included in the first ignition coil; a MOSFET that applies and interrupts the voltage boosted by the booster circuit to a primary coil included in the second ignition coil; and an ECU that starts electric discharge by the spark plug by controlling the power transistor, and repeatedly applies and interrupts the voltage boosted by the booster circuit by the MOSFET so that the electric discharge that is started is maintained.

An ignition device includes a spark plug, a measurement value detector, an electrical breakdown determiner, an AC voltage applying section, and a first changing section. The measurement value detector includes primary and secondary coils, and detects at least one measurement value among an ignition coil, a primary current, a primary voltage, a secondary current, and a secondary voltage. The electrical breakdown determiner determines whether a discharge has become an electrical breakdown state based on the measurement value. The AC voltage applying section applies an AC voltage of a first predetermined frequency that causes voltage resonance to the primary coil. The first changing section changes the frequency of the AC voltage to a second predetermined frequency that can maintain the electrical breakdown state and is lower in frequency than the first predetermined frequency when it is determined that the discharge has become the electrical breakdown state.

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.

It is possible to adjust electromagnetic energy introduced from a low-voltage side of a primary winding 20 of an ignition coil 2 after start discharging to a spark plug 1 from the ignition coil 2 in the correct proportion by threshold-determining either one or both of a primary voltage V1 applied to a primary side of the ignition coil 2 and a secondary current I2 flowing in a secondary side of the ignition coil 2, and by opening and closing a discharging switch 32 disposed between an auxiliary power supply 3 including an energy storage coil 330 and a low-voltage side terminal 201 of the ignition coil 2.

It is possible to adjust electromagnetic energy introduced from a low-voltage side of a primary winding 20 of an ignition coil 2 after start discharging to a spark plug 1 from the ignition coil 2 in the correct proportion by threshold-determining either one or both of a primary voltage V1 applied to a primary side of the ignition coil 2 and a secondary current I2 flowing in a secondary side of the ignition coil 2, and by opening and closing a discharging switch 32 disposed between an auxiliary power supply 3 including an energy storage coil 330 and a low-voltage side terminal 201 of the ignition coil 2.

To provide an ignition control device of an internal combustion engine capable of reducing the number of adjustment steps required for adjustment such as matching of a MOS gate voltage or the like without being affected by device variation. A detection voltage is generated on the basis of a primary current flowing through a current detection resistor having a positive temperature dependent characteristic. A reference voltage is generated by a potential difference between a base and an emitter of a first bipolar transistor circuit and a multiple type second bipolar transistor circuit in which a plurality of bipolar transistors are connected in parallel, and a resistance value of a first resistor connected to the emitter side of the plurality of the bipolar transistor circuit, on the basis of a current having a positive temperature dependent characteristic similar to the current detection resistor.

To provide an ignition control device of an internal combustion engine capable of reducing the number of adjustment steps required for adjustment such as matching of a MOS gate voltage or the like without being affected by device variation. A detection voltage is generated on the basis of a primary current flowing through a current detection resistor having a positive temperature dependent characteristic. A reference voltage is generated by a potential difference between a base and an emitter of a first bipolar transistor circuit and a multiple type second bipolar transistor circuit in which a plurality of bipolar transistors are connected in parallel, and a resistance value of a first resistor connected to the emitter side of the plurality of the bipolar transistor circuit, on the basis of a current having a positive temperature dependent characteristic similar to the current detection resistor.

In an ignition control device for controlling operation of an ignition apparatus, an ignition section has first and second electrodes disposed in a combustion chamber of an internal combustion engine. A voltage application between the first and second electrodes enables a discharge to be generated between the first and second electrodes for igniting a gas mixture in the combustion chamber. A voltage application section performs at least one application of a determination voltage between the first and second electrodes. An occurrence ratio acquisition section acquires a discharge occurrence ratio at the ignition section for the at least one application of the determination voltage. A comparison section compares the discharge occurrence ratio acquired by the occurrence ratio acquisition section with a predetermined determination threshold to thereby determine a degree of wear of at least one of the first and second electrodes.

In an ignition control device for controlling operation of an ignition apparatus, an ignition section has first and second electrodes disposed in a combustion chamber of an internal combustion engine. A voltage application between the first and second electrodes enables a discharge to be generated between the first and second electrodes for igniting a gas mixture in the combustion chamber. A voltage application section performs at least one application of a determination voltage between the first and second electrodes. An occurrence ratio acquisition section acquires a discharge occurrence ratio at the ignition section for the at least one application of the determination voltage. A comparison section compares the discharge occurrence ratio acquired by the occurrence ratio acquisition section with a predetermined determination threshold to thereby determine a degree of wear of at least one of the first and second electrodes.

Provided is an ignition system including: a main primary coil; a sub primary coil; a secondary coil; a control unit configured to: drive a main IC to switch a main primary coil mode from a de-energization mode to an energization mode; stop the drive of the main IC to switch the main primary coil mode from the energization mode to the de-energization mode; drive the sub IC to switch a sub primary coil mode from a de-energization mode to an energization mode; and stop the drive of the sub IC to switch the sub primary coil mode from the energization mode to the de-energization mode; and a detection circuit configured to detect a state of the secondary coil. The ignition system is configured such that the drive of the sub IC is stopped when the state of the secondary coil detected by the detection circuit is a no-current supply state.