An electronic device for the ignition system of an engine, which may incorporate circuitry for voltage amplification via transformer action, while also containing circuitry for sensing operational parameters, circuitry for calculation of derived values from the sensed data or operational parameters, circuitry for storage of the data and derived values, circuitry for engine system control, and circuitry for the wireless communication of data and derived values.

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 system of a combustion engine has a start-up adjustment curve with a maximum rotational speed, an operating adjustment curve and a switch-over device for switching between curves. The start-up adjustment curve is selected in the case of a start-up of the combustion engine. A rotational speed curve is divided into adjacent cycles. The start of the first cycle is the point in time of the second ignition after the start-up and the start of the subsequent cycles is in each case the point in time of ignition at which the rotational speed is less than in the case of the subsequent point in time of ignition. The criterion for switching to the operating adjustment curve is whether the average of the rotational speeds of successive cycles differs by less than a first tolerance value.

An internal combustion engine according to the present invention has an ignition control device. When a rotational speed of the internal combustion engine increases beyond a predetermined rotational over speed, the ignition control device advances an ignition timing of the ignition plug to a first BTDC angle where proper combustion is performed. Further, the ignition control device performs a misfire stroke or strokes of the ignition plug in one rotation or rotations of the crankshaft after the proper combustion is performed by activating the ignition plug at the first BTDC angle.

A delayed ignition control device comprises a charging circuit and a delayed ignition control circuit. In the delayed ignition control circuit, the resistor R6 is connected between the positive electrode of the input end of the photo coupling IC and the initial end of the power coil N3; the shut-off switch S1 is connected between the negative electrode of the input terminal of the photo coupling IC and the ground; the collector electrode of the photo coupling IC is connected with the initial end of the power coil N3; the output end of the photo coupling IC is connected with the anode of the diode D5; the voltage holding capacitor C2 is connected between the negative electrode of the diode D5 and the ground; and the resistor R8 is connected with the negative electrode of the diode D5 and the controller electrode of the silicon controlled SCR2.

An ignition coil has a core with a longitudinal axis, a secondary winding extending around the core, a sleeve extending around the core, a primary winding wrapped around the sleeve, and a controller connected to the primary winding so as to oscillate alternating current to said primary winding. The secondary winding has a high-voltage end and a low-voltage end. The primary winding is in spaced longitudinal relationship from the secondary winding. Specifically, the primary winding is located longitudinally away from the high-voltage end of the secondary winding. A bobbin is positioned over and around the core. The secondary winding is wrapped around at least a portion of the bobbin.

A control system for a small engine operated device includes an emitter carried by the engine or a portion of the device spaced from the engine and a control circuit. The control circuit may include memory with which control data related to device conditions, engine conditions or both is stored, and a processor in electrical communication with the first emitter. The control circuit provides a signal corresponding to the control data to the emitter so that the emitter provides an output in response to device conditions, engine conditions, or both.

The detection of the switching state of a stop switch at a switch terminal of an ignition device for an internal combustion engine is provided, in which an ignition pulse for controlling an electronic ignition switch is generated and a first power storage device is discharged via an ignition coil and during this discharge a voltage signal having negative and positive voltage half waves is generated, which is used for synchronizing a sampling, representing the switch state of the stop switch, particularly its closed position, of a voltage value at the switch terminal.