An ignition device for igniting an air-fuel mixture in a combustion chamber, in particular an internal combustion engine, having a spark plug, which has a first electrode and a second electrode, and 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 electrically connected to the first electrode of the spark plug via a first electrical conductor path such that the high voltage pulse is applied to the first electrode, wherein the second electrode is electrically connected to an electrical ground potential, wherein the spark plug has a third electrode, wherein the output of the high frequency voltage source is electrically connected to the third electrode via a second electrical conductor path, such that the high frequency alternating voltage is applied to the third electrode.

An ignition system includes a primary coil, a secondary coil, a first switch, a second switch, a third switch, a fourth switch, and a switch control section. The primary coil includes a first winding, and a second winding which is connected in series with the first winding. The secondary coil is connected to an ignition plug and is magnetically coupled to the primary coil. The first switch connects and disconnects an electrical path between a first terminal and a ground. The second switch connects and disconnects an electrical path between a power supply and a second terminal. The third switch connects and disconnects an electrical path between the power supply and the first terminal. The fourth switch connects and disconnects an electrical path between a contact point and the ground. The switch control section controls opening and closing of each switch to connect and disconnect the associated electrical path.

An ignition device for an internal combustion engine, having a housing in which a crankshaft sensor is accommodated for detecting the rotational speed and/or the position of a crankshaft, which is in particular provided with a toothed position sensor and in which at least one ignition transformer with a primary winding is accommodated, and a secondary winding for generating a spark for the internal combustion engine is accommodated, wherein a number of input ports, in particular for the connection of an electrical energy source for supplying the or each ignition transformer and/or for supplying sensor and/or control signals, and in which a plurality of output ports, in particular for connecting at least one spark plug and/or for emitting control signals, are provided.

An ignition apparatus of an internal combustion engine is provided with an ignition plug, an AC (alternating current) voltage application unit configured to apply AC voltage to the center electrode of the ignition plug, and an application voltage control unit that controls an operation of the AC voltage application unit. The application voltage control unit is configured to control the AC voltage application unit to apply the center electrode with a first AC voltage having an amplitude smaller than that of a required voltage of the ignition plug in a first period which is before an ignition timing, and to apply the center electrode with a second AC voltage having an amplitude smaller than that of the first AC voltage or to stop applying the center electrode with the AC voltage during a second period which is before the ignition timing after the first period has elapsed.

In a general aspect, an ignition circuit can include a control circuit that is coupled with an engine control unit (ECU) to receive a command signal from the ECU. The control circuit can include a multi-pulse generator configured to, in response to the command signal, generate a multi-pulse drive signal. The multi-pulse drive signal can include a first pulse cycle having a first duty cycle, a second pulse cycle having a second duty cycle, and a dwell period during which the multi-pulse drive signal continuously remains at a logic high value. The control circuit can be configured to provide the multi-pulse drive signal to an ignition switch coupled with the control circuit to receive the multi-pulse drive signal.

An internal combustion engine ignition system includes: a primary coil provided with a center tap; a third switching element that interrupts and conducts a primary current flowing from a voltage application unit to the center tap; a first switching element connected to one end on a first winding side; a second switching element connected to the other end on a second winding side; an ignition control circuit that controls operation of each of the above switching elements, thereby performing discharge generation control that allows an ignition plug to generate a spark discharge, and thereby interrupting and conducting the primary current flowing to the second winding to perform discharge maintenance control that maintains the spark discharge generated in the ignition plug; and a current circulation path that circulates a current flowing from the second winding to the second switching element.

The present invention relates to a gas heat pump and a control method therefor and, according to the present invention, the method for controlling a gas heat pump, which comprises an ignition plug and a gas engine having an engine combustion unit including a plurality of combustion spaces, may include: a target setting step of setting a target ignition energy amount on the basis of a refrigerant load amount determined according to a driving condition of the gas heat pump; an ignition step of igniting fuel injected into the combustion spaces; a comparison step of comparing an output energy amount emitted in the ignition step with a target ignition energy amount set in the target setting step; and a step of changing an energy amount required to ignite the fuel when the output energy amount and the target ignition energy amount do not coincide in the comparison step.

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 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 determining an in-cylinder pressure by analyzing a secondary current detected by a secondary current detection resistor, an engine controller is configured to detect an engine revolution speed and a discharge duration during which the secondary current flows. The discharge duration is correlated with a gas pressure between electrodes of a spark plug at ignition timing, that is, an in-cylinder pressure, and is different depending on the engine revolution speed. The engine controller is further configured to estimate the in-cylinder pressure at ignition timing based on the engine revolution speed and the discharge duration. An amount of time-dependent change in mechanical compression ratio, caused by accumulation of deposits, is detected based on the estimated in-cylinder pressure at ignition timing.