A booster circuit for use with an ignition system for an internal combustion engine is provided. The booster circuit includes a relay control circuitry disposed in parallel between the voltage source and the one or more ignition coils for igniting fuel in the engine in synchronism with engine operation; a controllable switching element for selectively completing a booster circuit for connecting the relay control circuitry in series with the voltage source and the one or more ignition coils; and the booster circuit having electronic circuitry including at least one output for providing booster energy at the at least one output, when the booster circuit is completed by the controllable switching element to assure producing of a suitable voltage applied to the one or more ignition coils.

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.

A barrier-discharge-type ignition apparatus that can accurately determine the application voltage, of a barrier ignition plug, that causes a non-ignition discharge to occur. In the barrier-discharge-type ignition apparatus, in a combustion assist control, the voltage difference between the one-period-prior application voltage and the present-period application voltage in the AC period is calculated based on an application voltage detected by a voltage detection circuit; then, it is determined whether or not a discharge exists in the barrier ignition plug, based on the comparison between the voltage difference and a preliminarily set discharge determination threshold value.

It is made possible to control ignition appropriately. An ignition device 1 for an internal combustion engine includes a spark coil 50 including: a primary side coil 51 connected to a direct current power supply 40 and a secondary side coil 52 magnetically connected to the primary side coil 51 and connected to an ignition plug 60; a switch element 30 that performs switching between energization and interruption of primary current I1 to the primary side coil 51; and a switch element controlling circuit 20 that controls the switch element 30 on the basis of an ignition controlling signal 51 supplied from an ECU 10. A turn-on delay adjustment circuit 22 that delays a control timing of the switch element 30 is disposed between the ECU 10 and the switch element 30 such that first resonance noise generated due to interruption of the primary current I1 to the primary side coil 51 is reduced.

Methods and systems are provided for multiplexing ignition signals in an engine system based on engine operating conditions, each cylinder of the engine system including a main chamber spark plug and a pre-chamber system. In one example, a method may include multiplexing spark signals to a first spark plug and a second spark plug, the first spark plug coupled to a pre-chamber of a first cylinder and the second spark plug coupled to a main chamber of a second cylinder. In this way, one ignition coil may be used to actuate two different spark plugs coupled to separate cylinders.

A system and method for detecting resonant frequency of a corona igniter concurrent with operation of the corona igniter is provided. The method includes providing a plurality of pulses of energy to the corona igniter, each having a pulse duration and spaced from one another by a deadtime duration during which no energy is provided to the corona igniter. Each pulse duration is ceased before current flowing in the corona igniter crosses zero, and each zero crossing of the current occurs during one of the deadtime durations. The next pulse of energy is provided to the corona igniter in response to the zero crossing of the current. A resonant frequency value is then obtained based on a sum of the pulse and deadtime durations of two consecutive cycles, or the time between zero crossings. The resonant frequency values become more accurate over time, and the drive frequency is adjusted accordingly.

An ignition device for igniting an air/fuel mixture in a combustion chamber, in particular of an internal combustion engine, having a spark plug which has a first electrode and a second electrode, having a high voltage source for generating an electrical high voltage pulse at an output of the high voltage source, and having a high frequency voltage source for generating an electrical high frequency alternating voltage at an output of the high frequency voltage source, wherein the output of the high voltage source is connected electrically to the first electrode of the spark plug via a first electrical conduction path in such a way that the high voltage pulse is present at the first electrode, wherein the output of the high frequency voltage source is connected electrically to the second electrode via a second electrical conduction path in such a way that the high frequency alternating voltage is present at the second electrode.

In at least some implementations, an auxiliary power supply in an ignition system for a light-duty combustion engine includes a first auxiliary winding and a second auxiliary winding coupled in parallel with the first auxiliary winding such that both windings are arranged to provide power to an auxiliary load. The first auxiliary winding may include a greater number of turns than the second auxiliary winding. A ratio of the number of turns in the first auxiliary winding to the number of turns in the second auxiliary winding may be between 1.5:1 and 10:1, the first auxiliary coil and the second auxiliary coil may have between 50 and 2,000 turns, and the first auxiliary coil and the second auxiliary coil are formed from wire between 25 and 45 gauge.

A booster circuit for use with an ignition system for an internal combustion engine is provided. The booster circuit includes a relay control circuitry disposed in parallel between the voltage source and the one or more ignition coils for igniting fuel in the engine in synchronism with engine operation; a controllable switching element for selectively completing a booster circuit for connecting the relay control circuitry in series with the voltage source and the one or more ignition coils; and the booster circuit having electronic circuitry including at least one output for providing booster energy at the at least one output, when the booster circuit is completed by the controllable switching element to assure producing of a suitable voltage applied to the one or more ignition coils.

Methods and systems are provided for multiplexing ignition signals in an engine system based on engine operating conditions, each cylinder of the engine system including a main chamber spark plug and a pre-chamber system. In one example, a method may include multiplexing spark signals to a first spark plug and a second spark plug, the first spark plug coupled to a pre-chamber of a first cylinder and the second spark plug coupled to a main chamber of a second cylinder. In this way, one ignition coil may be used to actuate two different spark plugs coupled to separate cylinders.