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.

The invention relates to an ignition device for triggering an ignition spark at a spark plug by way of an ignition generator. The latter includes a magnet wheel, which has two permanent magnets arranged at a spacing from each other in the peripheral direction and a magnetic yoke. The magnetic yoke carries a charging coil which charges an ignition capacitor, a primary coil and a secondary coil connected to the spark plug. During every passing of a permanent magnet, a voltage is induced in the coils, wherein, in order to trigger the ignition spark, the ignition capacitor is discharged via a switch element. In order to avoid an unwanted ignition at the bottom dead center of the piston, a device for reducing the voltage that occurs at the spark plug is provided.

A handheld engine-driven working machine comprises an internal combustion engine and an ignition control device; wherein the ignition control device can switch its control between a normal mode and a operation mode, wherein during the operation mode, the ignition timing within the high speed range is maintained at a second BTDC angle, and the ignition timing within the medium speed range is advanced more than a third BTDC angle between a first BTDC angle and the second BTDC angle, and wherein at any rotational speed within the medium speed range, the ignition timing during the operation mode is advanced more than the ignition timing during the normal mode.

A handheld engine-driven working machine comprises an internal combustion engine and an ignition control device; wherein the ignition control device can switch its control between a normal mode and a operation mode, wherein during the operation mode, the ignition timing within the high speed range is maintained at a second BTDC angle, and the ignition timing within the medium speed range is advanced more than a third BTDC angle between a first BTDC angle and the second BTDC angle, and wherein at any rotational speed within the medium speed range, the ignition timing during the operation mode is advanced more than the ignition timing during the normal mode.

An ignition control system performs discharge generation control, in which a discharge spark is generated, once or a plurality of times during a single combustion cycle. The ignition control system successively calculates an approximate energy density based on a secondary current and a discharge path length. During a predetermined period after blocking of a primary current is performed during a single combustion cycle, the ignition control system calculates an integrated value by integrating the discharge path length at this time, based on the approximate energy density being greater than a predetermined value. The ignition control system performs the discharge generation control again based on the calculated integrated value being less than a first threshold.

An ignition device for an internal combustion engine with a charging coil, in particular disposed on a yoke core, with a starter wheel to induce a charging voltage in the charging coil by its rotation, with a first energy store which is connected to the charging coil via a rectifier, as well as with an electrical load which for its power supply, in particular during the starting process of the internal combustion engine is connected to a second energy store, wherein the second energy store is connected to the first energy store via a voltage converter. Furthermore, the invention relates to an internal combustion engine with such an ignition device and a method for its operation.

In at least some implementations, a method of maintaining an engine speed below a first threshold, includes: (a) determining an engine speed; (b) comparing the engine speed to a second threshold that is less than the first threshold; (c) allowing an engine ignition event to occur during a subsequent engine cycle if the engine speed is less than the second threshold; and (d) skipping at least one subsequent engine ignition event if the engine speed is greater than the second threshold. In at least some implementations, the second threshold is less than the first threshold by a maximum acceleration of the engine after one ignition event so that an ignition event when the engine speed is less than the second threshold does not cause the engine speed to increase above the first threshold.

An ignition device for igniting an air/fuel mixture in at least one combustion chamber, having an ignition system with electrodes for each combustion chamber, a high-voltage source for generating an electrical high-voltage impulse at an output of the high-voltage source, and a high-frequency voltage source for generating an electrical high-frequency alternating voltage, wherein m ignition systems (10i) are provided with the formula (I) (natural numbers without zero) and m2, wherein K high-frequency voltage sources are provided with the formula (II), and K<m, wherein at least one power distributor device is provided which is electrically connected, on the one hand, to at least one high-frequency voltage source and, on the other hand, to n ignition systems, wherein formula (III) and 2nm, the power distributor device transmits the high-frequency alternating voltage or voltages from the high-frequency voltage source or sources to the ignition systems n.

A downlink communication data DND from a main control circuit section to a combination control circuit section is divided into first and second downlink data, high-speed communication using a downlink clock signal and a transmission start instruction signal is performed, a high-speed load which has been directly driven from the main control circuit section is indirectly driven at high speed from the combination control circuit section by the first downlink data, a low-speed analog input signal ANL which has been indirectly inputted to the combination control circuit section is inputted to a specific input channel of a multi-channel converter through an indirect multiplexer, and channel selection is made by the downlink communication data.

An ignition control apparatus according to one embodiment of the present invention is an ignition control apparatus which generates, in an ignition coil, a voltage to be supplied to a spark plug that is provided in an internal combustion engine on the basis of a pulse signal induced in the ignition coil of the internal combustion engine, wherein the ignition control apparatus comprises at least a switch element for passing current through and discharge the ignition coil, and a controlling unit that acquires the timing for discharge the ignition coil in response to a first pulse of the pulse signal, and controls the switch element so that a current flows through the ignition coil in response to a second pulse that follows the first pulse and the ignition coil is opened on the basis of the discharge timing acquired in response to the first pulse.