The objective is to obtain an internal-combustion-engine ignition apparatus that raises the ignitability at a time when a smolder occurs. An internal-combustion-engine ignition apparatus having a main combustion chamber and a subsidiary combustion chamber includes an ignition plug, an ignition coil having a primary coil, a secondary coil, and a tertiary coil, a first switching circuit that turns on or off energization of the primary coil, a second switching circuit that turns on or off energization of the tertiary coil, and a control apparatus that estimates a combustion state, that performs on/off-control of the first switching circuit so that a spark discharge is produced in the ignition plug and that performs on/off-control of the second switching circuit so that magnetic flux in the tertiary coil is changed so as to increase a secondary current, when deterioration of a combustion state has been estimated.

The objective is to obtain an internal-combustion-engine ignition apparatus that raises the ignitability at a time when a smolder occurs. An internal-combustion-engine ignition apparatus having a main combustion chamber and a subsidiary combustion chamber includes an ignition plug, an ignition coil having a primary coil, a secondary coil, and a tertiary coil, a first switching circuit that turns on or off energization of the primary coil, a second switching circuit that turns on or off energization of the tertiary coil, and a control apparatus that estimates a combustion state, that performs on/off-control of the first switching circuit so that a spark discharge is produced in the ignition plug and that performs on/off-control of the second switching circuit so that magnetic flux in the tertiary coil is changed so as to increase a secondary current, when deterioration of a combustion state has been estimated.

In a method for creating a spark across a spark gap, in particular for igniting a flammable liquid to measure its flash point, by means of a spark generator which comprises an ignition transformer, wherein the spark generator, on the primary side of the ignition transformer, comprises at least one DC voltage source and, on the secondary side of the ignition transformer, comprises two electrodes delimiting the spark gap to be formed, wherein voltage pulses from the DC voltage source are applied to the ignition transformer on the primary side thereof, which voltage pulses generate ignition voltage pulses on the secondary side, the ignition transformer is operated in a first phase according to the flyback converter principle and in a subsequent, second phase according to the forward converter principle.

A current flowing in a sub-primary coil can be limited in an ignition apparatus in which a voltage, generated in a secondary coil at a timing when a current in a main primary coil is cut off, generates a secondary current, and then the sub-primary coil is energized so that a superimposition current is generated in the secondary coil and in which a sub-IC connected in series with the sub-primary coil is pulse-controlled so that a current flowing in the sub-primary coil is controlled and hence the superimposition current is controlled.

A current flowing in a sub-primary coil can be limited in an ignition apparatus in which a voltage, generated in a secondary coil at a timing when a current in a main primary coil is cut off, generates a secondary current, and then the sub-primary coil is energized so that a superimposition current is generated in the secondary coil and in which a sub-IC connected in series with the sub-primary coil is pulse-controlled so that a current flowing in the sub-primary coil is controlled and hence the superimposition current is controlled.

In a method for creating a spark across a spark gap, in particular for igniting a flammable liquid to measure its flash point, by means of a spark generator which comprises an ignition transformer, wherein the spark generator, on the primary side of the ignition transformer, comprises at least one DC voltage source and, on the secondary side of the ignition transformer, comprises two electrodes delimiting the spark gap to be formed, wherein voltage pulses from the DC voltage source are applied to the ignition transformer on the primary side thereof, which voltage pulses generate ignition voltage pulses on the secondary side, the ignition transformer is operated in a first phase according to the flyback converter principle and in a subsequent, second phase according to the forward converter principle.