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. One end of the comparator is connected to the module signal input end, and the other end is connected to a comparison resistance R that is grounded. The ignition drive module further comprises a maximum dwell timer module connected to the comparator, a logical judgment module connected to the comparator, and an IGBT module connected to the logical judgment module which receives the signals from the maximum dwell timer module and the comparator to determine whether to activate the IGBT module. The output end of the IGBT module is connected to the module signal output end.

In at least some implementations, a method of operating an ignition system for a combustion engine includes charging an energy storage device during at least a portion of the time when the engine is operating, permitting the level of energy stored on the charge storage device to decrease over time after the engine ceases to operate, determining the energy level on the energy storage device when the engine is restarted after having ceased operating, and setting at least one engine operational parameter as a function of the determined energy level. In at least some implementations, the at least one engine operational parameter may include one or more of: richness of a fuel and air mixture to be delivered to the engine, ignition timing, desired engine idle speed.

Provided is a stroke determination device which detects a secondary output from an ignition coil without using a high breakdown voltage element, and is capable of accurately establishing the stroke being carried out during an ignition operation of a four-stroke engine from the waveform of the detected secondary output. In the present invention, a secondary coil of an ignition coil is constituted from a first coil portion, and a second coil portion wound so as to have fewer windings than does the first coil portion and connected in series to the first coil portion. A tap is drawn out from a boundary part between both coil portions, the voltage at both ends of the second coil portion or the current flowing through the second coil portion is detected through the tap, and a parameter to be used in stroke determination is detected from the waveform of the detected voltage or current.

An igniter includes a switch element with input, output control electrodes, a first lead in contact with the input electrode and connected to a primary coil of an ignition coil, a second lead that is grounded, a third lead spaced apart from the first and second leads, a first bonding wire connecting the output electrode and the third lead, a second bonding wire connecting the third lead and the second lead, and a control IC that drives the switch element based on an ignition instruction signal from an engine control unit. The control IC generates an ignition confirmation signal based on the voltage of the third lead, and outputs the signal to the engine control unit.

An igniter includes a switch element with input, output control electrodes, a first lead in contact with the input electrode and connected to a primary coil of an ignition coil, a second lead that is grounded, a third lead spaced apart from the first and second leads, a first bonding wire connecting the output electrode and the third lead, a second bonding wire connecting the third lead and the second lead, and a control IC that drives the switch element based on an ignition instruction signal from an engine control unit. The control IC generates an ignition confirmation signal based on the voltage of the third lead, and outputs the signal to the engine control unit.

The subject matter of this specification can be embodied in, among other things, a method that includes receiving a collection of measurements of electric current amplitude in a primary winding of an engine ignition system having the primary winding and a spark plug, identifying an ignition start time, identifying an inflection point based on the plurality of measurements, determining an inflection point time representative of a time at which the identified inflection point occurred, determining a spark start time based on an amount of time between the ignition start time and the inflection point time, and providing a signal indicative of the spark start time.

To provide an ignition apparatus which can turn on and off the sub primary coil according to extension degree of the discharge path of the spark discharge. An ignition apparatus is provided with an ignition coil that is provided with a main primary coil, a sub primary coil which generates energization magnetic flux of a direction opposite to the energization magnetic flux of the main primary coil, and a secondary coil which is magnetically coupled with the main primary coil and the sub primary coil and supplies spark discharge energy to a spark plug; and after turning off energization to the main primary coil, based on a detection value of terminal voltage of the main primary coil, turns on and off the sub switch circuit to turn on and off energization to the sub primary coil and additionally supply spark discharge energy to the secondary coil.

To provide an ignition apparatus which can turn on and off the sub primary coil according to extension degree of the discharge path of the spark discharge. An ignition apparatus is provided with an ignition coil that is provided with a main primary coil, a sub primary coil which generates energization magnetic flux of a direction opposite to the energization magnetic flux of the main primary coil, and a secondary coil which is magnetically coupled with the main primary coil and the sub primary coil and supplies spark discharge energy to a spark plug; and after turning off energization to the main primary coil, based on a detection value of terminal voltage of the main primary coil, turns on and off the sub switch circuit to turn on and off energization to the sub primary coil and additionally supply spark discharge energy to the secondary coil.

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.