Abstract: An ignition apparatus includes: sparking coil supplying a sparking plug with a high voltage; an energy supply device supplying the sparking coil with energy; a first switch disposed therebetween; and a control device controlling the first switch's conduction. The energy supply device has a DC power supply, a resonance coil connected to the DC power supply, a sparking capacitor connected to the resonance coil, and a second switch disposed between the sparking capacitor and an earth, and charges the sparking capacitor to have a voltage value larger than that of the DC power supply in absolute value by making the resonance coil and the sparking capacitor generate an LC resonance when the second and first switches are turned ON and OFF, respectively, according to an instruction from the control device whereas supplying the sparking coil with energy when the second and first switches are operated inversely according to another instruction.

Abstract: The ion current detector includes: an ion bias circuit for supplying a bias voltage to an electrode of the ignition plug so as to cause the ignition plug to generate a spark discharge; and an ion current detection circuit for detecting an ion current generated in a combustion chamber by the spark discharge and for amplifying the detected ion current to output an ion current detection signal. The ion current detection circuit amplifies the ion current at an ion current amplification factor switched between a time when an ignition signal is supplied and a time when the ignition signal is not supplied. Specifically, when the ignition signal is supplied, the ion current amplification factor is set to a low value (approximately 50). When the ignition signal is not supplied, the ion current amplification factor is set to a high value (250 or more).

Abstract: A resonance inductor is connected with a charging path through which an ignition condenser is charged; a first switching device controls charging of the ignition condenser; discharging of the ignition condenser is controlled by a second switching device whose collector terminal is connected with the other end of the primary coil of an ignition coil unit and whose emitter terminal is connected with the negative-polarity terminal of the ignition condenser; a clamp diode is connected between the one end of the primary coil and the collector terminal of the second switching device.

Abstract: A resonance inductor is connected with a charging path through which an ignition condenser is charged; a first switching device controls charging of the ignition condenser; discharging of the ignition condenser is controlled by a second switching device whose collector terminal is connected with the other end of the primary coil of an ignition coil unit and whose emitter terminal is connected with the negative-polarity terminal of the ignition condenser; a clamp diode is connected between the one end of the primary coil and the collector terminal of the second switching device.

Abstract: A power circuit, which supplies plasma energy to a spark plug, includes a DC/DC converter which charges a tank capacitor, a voltage limiting circuit which restricts an output voltage of the converter to a predetermined value, a PJ capacitor which is connected to the output side of the converter and is charged by the tank capacitor, and a high breakdown voltage switch which is connected between the PJ capacitor and the DC/DC converter and controls a charging time period of the PJ capacitor in response to operating conditions of an internal combustion engine; and the power circuit switches a voltage limiting value of the tank capacitor for charging the PJ capacitor in synchronization with a driving signal of the high breakdown voltage switch.

Abstract: A plasma ignition device comprising: an ignition plug; an ignition circuit applying a high voltage to the plug to start discharge; a power supply circuit including a battery section for supplying an electric energy to a discharge space of the plug having impedance reduced by discharge start, and a charging section charging the battery section with a boosted voltage by a booster circuit, wherein the power supply circuit including: a first means 610 for stopping a boosting operation of the booster circuit when the charging section voltage is equal or higher than a first reference for high-voltage abnormality; a second means 630 for detecting the charging section abnormal voltage by comparison with a second reference for low-voltage abnormality for detecting ground to conduct a given control on the power supply circuit; a third means 600 for invalidating the control of the second means until the charging section is sufficiently charged.

Abstract: An ignition apparatus includes: sparking coil supplying a sparking plug with a high voltage; an energy supply device supplying the sparking coil with energy; a first switch disposed therebetween; and a control device controlling the first switch's conduction. The energy supply device has a DC power supply, a resonance coil connected to the DC power supply, a sparking capacitor connected to the resonance coil, and a second switch disposed between the sparking capacitor and an earth, and charges the sparking capacitor to have a voltage value larger than that of the DC power supply in absolute value by making the resonance coil and the sparking capacitor generate an LC resonance when the second and first switches are turned ON and OFF, respectively, according to an instruction from the control device whereas supplying the sparking coil with energy when the second and first switches are operated inversely according to another instruction.

Abstract: A power circuit, which supplies plasma energy to a spark plug, includes a DC/DC converter which charges a tank capacitor, a voltage limiting circuit which restricts an output voltage of the converter to a predetermined value, a PJ capacitor which is connected to the output side of the converter and is charged by the tank capacitor, and a high breakdown voltage switch which is connected between the PJ capacitor and the DC/DC converter and controls a charging time period of the PJ capacitor in response to operating conditions of an internal combustion engine; and the power circuit switches a voltage limiting value of the tank capacitor for charging the PJ capacitor in synchronization with a driving signal of the high breakdown voltage switch.

Abstract: A plasma power supply circuit includes a DC/DC converter connected to a DC power supply and outputting a DC voltage, a voltage limit circuit limiting an output voltage from the DC/DC converter to a predetermined value, a PJ capacitor connected to an output end of the DC/DC converter and charged with electric energy used to generate a plasma in a discharge space of the spark plug, and a high-voltage switch connected between the PJ capacitor and the DC/DC converter and controlled to switch ON and OFF so that a charge period of the PJ capacitor is controlled according to running conditions of the internal combustion engine. Hence, the plasma ignition device can prevent damage on an electronic component incorporated therein even at the occurrence of a short and lessen damage on the internal combustion engine caused by an erroneous plasma jet ejection, wearing of the spark plug, and power consumption.

Abstract: To provide a plasma ignition system that can prevent damage on an internal combustion engine due to erroneous ejection of a plasma jet, and further, even when the required voltage of an ignition plug becomes lower, can prevent erroneous ignition by the charged voltage of a PJ capacitor. A plasma power supply circuit of the plasma ignition system includes a voltage-limiting circuit having a first set voltage having an absolute value lower relative to the discharge voltage of the ignition coil, and a second set voltage having an absolute value higher relative to the discharge voltage of the ignition coil, and the first set voltage and the second set voltage are selectively switched according to an operation condition of the internal combustion engine.

Abstract: A plasma power supply circuit includes a DC/DC converter connected to a DC power supply and outputting a DC voltage, a voltage limit circuit limiting an output voltage from the DC/DC converter to a predetermined value, a PJ capacitor connected to an output end of the DC/DC converter and charged with electric energy used to generate a plasma in a discharge space of the spark plug, and a high-voltage switch connected between the PJ capacitor and the DC/DC converter and controlled to switch ON and OFF so that a charge period of the PJ capacitor is controlled according to running conditions of the internal combustion engine. Hence, the plasma ignition device can prevent damage on an electronic component incorporated therein even at the occurrence of a short and lessen damage on the internal combustion engine caused by an erroneous plasma jet ejection, wearing of the spark plug, and power consumption.

Abstract: To provide a plasma ignition system that can prevent damage on an internal combustion engine due to erroneous ejection of a plasma jet, and further, even when the required voltage of an ignition plug becomes lower, can prevent erroneous ignition by the charged voltage of a PJ capacitor. A plasma power supply circuit of the plasma ignition system includes a voltage-limiting circuit having a first set voltage having an absolute value lower relative to the discharge voltage of the ignition coil, and a second set voltage having an absolute value higher relative to the discharge voltage of the ignition coil, and the first set voltage and the second set voltage are selectively switched according to an operation condition of the internal combustion engine.

Abstract: A plasma ignition device comprising: an ignition plug; an ignition circuit applying a high voltage to the plug to start discharge; a power supply circuit including a battery section for supplying an electric energy to a discharge space of the plug having impedance reduced by discharge start, and a charging section charging the battery section with a boosted voltage by a booster circuit, wherein the power supply circuit including: a first means 610 for stopping a boosting operation of the booster circuit when the charging section voltage is equal or higher than a first reference for high-voltage abnormality; a second means 630 for detecting the charging section abnormal voltage by comparison with a second reference for low-voltage abnormality for detecting ground to conduct a given control on the power supply circuit; a third means 600 for invalidating the control of the second means until the charging section is sufficiently charged.

Abstract: The ion current detector includes: an ion bias circuit for supplying a bias voltage to an electrode of the ignition plug so as to cause the ignition plug to generate a spark discharge; and an ion current detection circuit for detecting an ion current generated in a combustion chamber by the spark discharge and for amplifying the detected ion current to output an ion current detection signal. The ion current detection circuit amplifies the ion current at an ion current amplification factor switched between a time when an ignition signal is supplied and a time when the ignition signal is not supplied. Specifically, when the ignition signal is supplied, the ion current amplification factor is set to a low value (approximately 50). When the ignition signal is not supplied, the ion current amplification factor is set to a high value (250 or more).

Abstract: An internal combustion engine ignition device is provided in which an ECU (200) includes a pulse generation circuit (201) that outputs pulse signals (Igt1 and Igt2) and an ion-signal detection/control circuit (300), and a coil driver (400) includes a pulse detection circuit (7) that recognizes a signal received from the pulse generation circuit (201) and an ion-current detection circuit (9); when the pulse signals are not outputted, an ion current is detected and a signal is outputted at the same line as a coil-driver input signal line.

Abstract: An internal combustion engine ignition device is provided in which an ECU (200) includes a pulse generation circuit (201) that outputs pulse signals (Igt1 and Igt2) and an ion-signal detection/control circuit (300), and a coil driver (400) includes a pulse detection circuit (7) that recognizes a signal received from the pulse generation circuit (201) and an ion-current detection circuit (9); when the pulse signals are not outputted, an ion current is detected and a signal is outputted at the same line as a coil-driver input signal line.

Abstract: An ignition device, including: an ignition coil (1) having a primary coil and a secondary coil; a switching element (5) for causing a primary current to be conducted through and shut off from the primary coil of the ignition coil; a waveform shaping circuit (6) for shaping a waveform of an ignition signal transmitted from an outside through a signal line to supply a conduction signal thus obtained to the switching element; ion current detecting means (8, 9) connected to the secondary coil of the ignition coil, for detecting an ion current flowing through the secondary coil; and ion signal generating means (10, 11, 12) for outputting an ion signal, which indicates the ion current detected for a predetermined period after the conduction signal of the waveform shaping circuit has been turned off, to the outside through the signal line while invalidating the conduction signal from the waveform shaping circuit.

Abstract: An ignition apparatus for an internal combustion engine can be produced at low cost and small size by preventing the generation of a spark at a spark plug due to a turn-on voltage with a simple ignition coil construction having no energy loss. The apparatus include an ignition coil having a primary coil and a secondary coil, a spark plug to which a high voltage from the secondary coil is impressed, and a coil driver for driving the ignition coil. The coil driver has a switching element for controlling the primary current, an IC for driving the switching element, and a turn-on voltage prevention circuit inserted between a secondary coil low-voltage side terminal and ground. The turn-on voltage prevention circuit is composed of a parallel circuit comprising a diode in the form of a bare chip and a thick film resistor, and is mounted on the same substrate together with the IC.

Abstract: An ignition device, including: an ignition coil (1) having a primary coil and a secondary coil; a switching element (5) for causing a primary current to be conducted through and shut off from the primary coil of the ignition coil; a waveform shaping circuit (6) for shaping a waveform of an ignition signal transmitted from an outside through a signal line to supply a conduction signal thus obtained to the switching element; ion current detecting means (8, 9) connected to the secondary coil of the ignition coil, for detecting an ion current flowing through the secondary coil; and ion signal generating means (10, 11, 12) for outputting an ion signal, which indicates the ion current detected for a predetermined period after the conduction signal of the waveform shaping circuit has been turned off, to the outside through the signal line while invalidating the conduction signal from the waveform shaping circuit.

Abstract: An ignition apparatus for an internal combustion engine can be produced at low cost and small size by preventing the generation of a spark at a spark plug due to a turn-on voltage with a simple ignition coil construction having no energy loss. The apparatus include an ignition coil having a primary coil and a secondary coil, a spark plug to which a high voltage from the secondary coil is impressed, and a coil driver for driving the ignition coil. The coil driver has a switching element for controlling the primary current, an IC for driving the switching element, and a turn-on voltage prevention circuit inserted between a secondary coil low-voltage side terminal and ground. The turn-on voltage prevention circuit is composed of a parallel circuit comprising a diode in the form of a bare chip and a thick film resistor, and is mounted on the same substrate together with the IC.