The present disclosure relates to gas turbine engine operation in which an igniter assembly is provided with an electrical energy input (e.g., an electrical waveform) that is configured to increase a likelihood of igniting a fuel-air mixture surrounding the igniter assembly. In certain embodiments, the igniter assembly is supplied with an augmented electrical waveform that may reduce a quantity of sparks generated by the igniter assembly before successful light-off (e.g., ignition) of the fuel-air mixture is achieved (e.g., as compared to a quantity of sparks generated to achieve ignition by an igniter assembly that receives an electrical energy input in the form of a conventional electrical waveform). Accordingly, the augmented electrical waveform may reduce wear (e.g., via oxidation) on electrodes of the igniter assembly, such as a primary electrode (e.g., a center electrode) and a secondary electrode (e.g., an outer shell electrode) disposed about the primary electrode.

The present disclosure relates to gas turbine engine operation in which an igniter assembly is provided with an electrical energy input (e.g., an electrical waveform) that is configured to increase a likelihood of igniting a fuel-air mixture surrounding the igniter assembly. In certain embodiments, the igniter assembly is supplied with an augmented electrical waveform that may reduce a quantity of sparks generated by the igniter assembly before successful light-off (e.g., ignition) of the fuel-air mixture is achieved (e.g., as compared to a quantity of sparks generated to achieve ignition by an igniter assembly that receives an electrical energy input in the form of a conventional electrical waveform). Accordingly, the augmented electrical waveform may reduce wear (e.g., via oxidation) on electrodes of the igniter assembly, such as a primary electrode (e.g., a center electrode) and a secondary electrode (e.g., an outer shell electrode) disposed about the primary electrode.

The present invention provides spark plug that can improve detection accuracy of pre-ignition caused by flame kernel occurring inside spark plug. Terminal is located at a rear end side with respect to thread portion of metal shell. Detector electrode is provided at a portion located at a top end side with respect to a top end of contact portion between reduced diameter portion and shelf portion or packing in a space formed between outer periphery of insulator and inner periphery of the metal shell. The detector electrode and the terminal are connected by conductor. The detector electrode and the conductor are insulated from center electrode, the metal shell and ground electrode. Since the detector electrode is located in the space between the outer periphery of the insulator and the inner periphery of the metal shell, an early detection of the flame kernel occurring in this space can be possible.

Disclosed is an ignition apparatus for an internal combustion engine. The ignition apparatus includes a spark plug, an ignition coil and a controller. The spark plug has an auxiliary combustion chamber in which a discharge gap is arranged. The ignition coil is configured to apply a voltage to the spark plug. The controller is configured to perform a multiple-discharge mode in which discharge is generated at least twice, with a discharge pause period intervening therebetween, across the discharge gap within a period from a compression stroke to an expansion stroke of the internal combustion engine.

A Marx configuration has a housing surrounding an interior, and a Marx generator arranged in the interior. The Marx generator has a plurality of capacitor stages connected in series, each having at least one first and one second voltage terminal, and respective cross branches. Each two adjacent capacitor stages between the first terminal of the preceding and the second terminal of the following capacitor stage are connected by one of the cross branches. Each of the cross branches contains a spark gap, a sealed gas space for an insulating gas for the spark gaps which are arranged in the interior and at least two of the spark gaps. All spark gaps are arranged in a respective gas space, and the interior contains a sealed fluid space for a cooling fluid for the Marx generator. A base support disposed in the interior and surrounds the gas space partially.

A Marx configuration has a housing surrounding an interior, and a Marx generator arranged in the interior. The Marx generator has a plurality of capacitor stages connected in series, each having at least one first and one second voltage terminal, and respective cross branches. Each two adjacent capacitor stages between the first terminal of the preceding and the second terminal of the following capacitor stage are connected by one of the cross branches. Each of the cross branches contains a spark gap, a sealed gas space for an insulating gas for the spark gaps which are arranged in the interior and at least two of the spark gaps. All spark gaps are arranged in a respective gas space, and the interior contains a sealed fluid space for a cooling fluid for the Marx generator. A base support disposed in the interior and surrounds the gas space partially.

A plasma assisted spark ignition system includes an ignitor and a power supply. The first ignitor includes: a casing having a first end, a second end that forms a first electrode, and a longitudinally extending passage, a second electrode which protrudes longitudinally outward from an opening at the second end of the casing and laterally spaced inwardly to form a spark gap, and an electrical insulator (dielectric) surrounding a portion of the second electrode, and which has a terminus that is at least closely spaced to an interior surface of the end of the casing. The power supply supplies a plurality of voltage pulses to the ignitor per ignition event to generate a flash over on the dielectric. Subsequent pulses in an ignition event may be at lower amplitude than an initial pulse in the ignition event. Pulses may, for example, have a duration on the order of a nanosecond.

A plasma assisted spark ignition system includes an ignitor and a power supply. The first ignitor includes: a casing having a first end, a second end that forms a first electrode, and a longitudinally extending passage, a second electrode which protrudes longitudinally outward from an opening at the second end of the casing and laterally spaced inwardly to form a spark gap, and an electrical insulator (dielectric) surrounding a portion of the second electrode, and which has a terminus that is at least closely spaced to an interior surface of the end of the casing. The power supply supplies a plurality of voltage pulses to the ignitor per ignition event to generate a flash over on the dielectric. Subsequent pulses in an ignition event may be at lower amplitude than an initial pulse in the ignition event. Pulses may, for example, have a duration on the order of a nanosecond.

An ignition device for an internal combustion engine includes: an ignition plug; a primary coil; a secondary coil magnetically linked to the primary coil and connected to the ignition plug; a main ignition circuit causing a spark discharge to occur in the ignition plug; an energy supply circuit that supplies and stops electrical energy to the predetermined winding of the primary coil to accordingly cause the spark discharge to continue; a recirculation circuit that permits and prohibits current recirculation through a recirculation path including the predetermined winding; and a controller configured to: control the main ignition circuit, and determine a start time of a permission of the current recirculation by the recirculation circuit using, as a trigger, the interruption signal which causes the main ignition circuit to interrupt the current through the primary coil, and end the permission after a predetermined time period has elapsed since the start time.

An ignition device for an internal combustion engine includes: an ignition plug; a primary coil; a secondary coil magnetically linked to the primary coil and connected to the ignition plug; a main ignition circuit causing a spark discharge to occur in the ignition plug; an energy supply circuit that supplies and stops electrical energy to the predetermined winding of the primary coil to accordingly cause the spark discharge to continue; a recirculation circuit that permits and prohibits current recirculation through a recirculation path including the predetermined winding; and a controller configured to: control the main ignition circuit, and determine a start time of a permission of the current recirculation by the recirculation circuit using, as a trigger, the interruption signal which causes the main ignition circuit to interrupt the current through the primary coil, and end the permission after a predetermined time period has elapsed since the start time.