Abstract: 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.

Abstract: A circuit for providing a follow-on current between the electrodes of a traveling spark ignitor after an initial break down between the electrodes has occurred is disclosed. The circuit may include first and second portions which, respectively, provide first and second voltages to the ignitor. The first portion may be a conventional ignition circuit. The second portion provides the follow-on current. The second portion may provide the follow-on current as a single discharge or as a multi-stage discharge.

Abstract: In one embodiment, a system for providing electrical energy to a traveling spark ignitor operating in an internal combustion engine is disclosed. The system may include a conventional ignition system connected to the ignitor and a follow-on current producer which produces a follow-on current that travels between electrodes of the ignitor after an initial discharge of the conventional ignition system through the ignitor. The system may also include a disabling element that prevents the follow-on current from being transmitted to the ignitor. The disabling element may prevent the follow-on current from being transmitted to the ignitor based upon current operating conditions of the engine. When the disabling element prevents the follow-on current from being transmitted to the ignitor the system operates in a conventional manner.

Abstract: An ignitor and associated electronics for igniting a combustible mixture in a cylinder of an internal combustion engine are described. The ignitor includes at least two spaced-apart electrodes that define a discharge gap. The space between the electrodes is substantially filled with a dielectric material. The dielectric material is spaced-apart from at least one of the electrodes to provide an air gap over which an initial voltage breakdown between the electrodes will occur. The air gap serves to vary the location of the initial breakdown and as a barrier to a short circuit between the electrodes due to carbon and/or metal deposit buildup on the dielectric material. The associated electronics provide a first potential between the electrodes that generates a plasma between the electrodes. Then the volume of the plasma is increased by the application of a second potential that creates a current through the plasma.

Abstract: A plasma ignitor, or plasma source, for igniting a combustible mixture in an internal combustion engine. The ignitor includes at least two spaced apart electrodes dimensioned and arranged such that an outwardly moving plasma is formed when a voltage is applied across the electrodes. The present invention is characterized by its efficient use of input electrical energy for driving the plasma ignitor and by an ignition plasma kernel which is several orders of magnitude larger than that produced by conventional spark plugs. Outward motion and expansion of the plasma kernel is produced by a combination of Lorentz and thermal forces. Use of very lean combustible mixtures, in which the dilution of the mixture is achieved by use of exhaust gas recirculation, is made possible by the present ignition system. Improvement in engine efficiency, and a major reduction in exhaust gas pollutants are obtained.

Abstract: An high efficiency low energy ignitor and associated electrical systems for creating larger plasma ignition kernels to ignite a gaseous mixture of air fuel in a combustion engine is described. The apparatus has at least two spaced apart electrodes having a discharge gap between them. When a sufficiently high first potential is applied between the electrodes a plasma is formed from the air fuel. The volume of this plasma is increased by the application of a second voltage that creates a current through the plasma. The location where the current travels through the plasma is swept outward along with the plasma, due to the interaction of Lorentz and thermal expansion forces. This leads to a larger volume of plasma being created and thereby increases the efficiency of the burn cycle of the combustion engine. Also described are dimensioning characteristics related to the electrodes and the space between them that achieve optimal plasma formation and expulsion.