An igniter includes a switch element and a switch control apparatus. An ignition signal IGT is input to an input line of the switch control apparatus. A high-frequency filter removes high-frequency noise from the input line. A voltage comparator compares an output voltage V.sub.FIL of the high-frequency filter with a reference voltage V.sub.REF, so as to generate a judgment signal S.sub.DET. A driving stage controls an on/off switching operation of the switch element according to the judgment signal S.sub.DET. An off-state dead-time circuit prohibits the switch element from turning off during a predetermined dead time after the judgment signal S.sub.DET transits to a negated level that corresponds to the off state of the switch element.

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.

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.

A method of controlling an engine is provided, which includes the steps of injecting main fuel by a fuel injector during an intake stroke or a compression stroke, providing a mixture gas containing fuel and air inside a cylinder, applying by an ignition device a high voltage between electrodes of a spark plug at a timing when the mixture gas is not ignited, detecting a parameter related to a current value of an electric-discharge channel generated between the electrodes, determining by a controller whether the detected parameter is within a range between a first threshold and a second threshold to determine a flowing state of a vortex inside the cylinder, operating the spark plug to carry out a supplemental ignition when the parameter is determined to be outside the range, and igniting the mixture gas by operation of the spark plug after the supplemental ignition.

A spark plug heat up method via transient control of the spark discharge current. The high temperature plasma channel is used to heat up the central electrode, and the temperature and energy of the plasma channel are realized via transient control of the discharge current. The heating up process takes place before firing the engine, using discharge current to actively heat up the spark plug from inside. By monitoring the discharge current amplitude and discharge duration, the temperature change of the central electrode and the ceramic insulator can be carefully measured and controlled within a proper window. This method can be used to measure the heating range of the spark plug, and to prevent or remove the carbon deposit on the central electrode and the ceramic insulator generated under various engine operation conditions, such as engine cold start, full load operation, and heavy EGR condition, as well as realize self-cleaning.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

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.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.