An ignition device includes: a primary coil including a first winding and a second winding connected in series to the first winding; a secondary coil connected to a spark plug and magnetically coupled to the primary coil; a first switch that opens or closes the electrical path between the first terminal and the ground; a second switch that opens or closes the electrical path between the power source and the second terminal; a third switch that opens or closes the electrical path between the power source and the connection point; a fourth switch that opens or closes the electrical path between the second terminal and the ground; and a switch control unit that controls the opening and closing of each switch to open or close each electrical path.

An ignition device includes: a primary coil including a first winding and a second winding connected in series to the first winding; a secondary coil connected to a spark plug and magnetically coupled to the primary coil; a first switch that opens or closes the electrical path between the first terminal and the ground; a second switch that opens or closes the electrical path between the power source and the second terminal; a third switch that opens or closes the electrical path between the power source and the connection point; a fourth switch that opens or closes the electrical path between the second terminal and the ground; and a switch control unit that controls the opening and closing of each switch to open or close each electrical path.

A control device is provided for a compression ignition engine, which controls so that partial compression ignition combustion of A/F-lean mixture gas is carried out in a specific range where an engine load is low. In a first range of the specific range, a normal ignition in which sparks are generated in a late period of compression stroke or an early period of expansion stroke to start SI combustion, and a preceding ignition in which sparks are generated at a timing included in intake stroke or compression stroke and earlier than the normal ignition by a given amount or more are performed, and fuel is injected at a timing where fuel is present before the preceding ignition inside the combustion chamber. In a high-load side second range of the specific range, at least the normal ignition is performed and the execution of the preceding ignition is limited.

An ignition system including a spark plug control unit adapted to control at least two coil stages to provide a current to a spark plug, including two stages including a first transformer including a first primary winding inductively coupled to a first secondary winding; a second transformer including a second primary winding inductively coupled to a second secondary winding; the control unit enabled to simultaneously switch on and off two corresponding switches to maintain a continuous ignition fire, and includes a step-down converter stage with a switch and a diode. The method includes i) switching off the switch; and ii) toggling the two corresponding switches.

An ignition system including a spark plug control unit adapted to control at least two coil stages to provide a current to a spark plug, including two stages including a first transformer including a first primary winding inductively coupled to a first secondary winding; a second transformer including a second primary winding inductively coupled to a second secondary winding; the control unit enabled to simultaneously switch on and off two corresponding switches to maintain a continuous ignition fire, and includes a step-down converter stage with a switch and a diode. The method includes i) switching off the switch; and ii) toggling the two corresponding switches.

A control method of an internal combustion engine including a spark plug and a fuel injection valve includes starting electric discharge of the spark plug after a gas flow in a direction from a side of the fuel injection valve toward a side of the spark plug is generated at a position of an electric discharge gap of the spark plug due to spray of the fuel injected from the fuel injection valve.

An ignition control device is provided with an ignition coil including a primary coil and a secondary coil, a main ignition circuit performing a main ignition operation, an energy input circuit that performs an energy input operation for superposing a current having the same polarity to a secondary current, in which a signal generation circuit is provided to generate, based on a main ignition signal that controls the main ignition operation, at least one of an energy input signal controlling the energy input operation and a target secondary current command signal commanding a target secondary current value.

In an ignition control device for an internal-combustion engine, signal separation circuitry receives and separates an ignition control signal that is an integrated signal of a main ignition signal for controlling the main ignition operation, an energy input signal for controlling the energy input operation, and a target secondary current command signal. The ignition control signal is formed of a first signal and a second signal that are pulsed signals. The signal separation circuitry is configured to generate, from the ignition control signal, the main ignition signal based on rising edges of the first signal and the second signal as pulse-waveform information of the first signal and the second signal, generate the energy input signal based on a pulse width of the second signal as pulse-waveform information of the second signal, and generate the target secondary current command signal based on pulse-waveform information of the first signal.

An ignition system includes a primary coil, a secondary coil, a first switch, a second switch, a third switch, a fourth switch, and a switch control section. The primary coil includes a first winding, and a second winding which is connected in series with the first winding. The secondary coil is connected to an ignition plug and is magnetically coupled to the primary coil. The first switch connects and disconnects an electrical path between a first terminal and a ground. The second switch connects and disconnects an electrical path between a power supply and a second terminal. The third switch connects and disconnects an electrical path between the power supply and the first terminal. The fourth switch connects and disconnects an electrical path between a contact point and the ground. The switch control section controls opening and closing of each switch to connect and disconnect the associated electrical path.

An ignition system includes a primary coil, a secondary coil, a first switch, a second switch, a third switch, a fourth switch, and a switch control section. The primary coil includes a first winding, and a second winding which is connected in series with the first winding. The secondary coil is connected to an ignition plug and is magnetically coupled to the primary coil. The first switch connects and disconnects an electrical path between a first terminal and a ground. The second switch connects and disconnects an electrical path between a power supply and a second terminal. The third switch connects and disconnects an electrical path between the power supply and the first terminal. The fourth switch connects and disconnects an electrical path between a contact point and the ground. The switch control section controls opening and closing of each switch to connect and disconnect the associated electrical path.