In at least some implementations, a method of controlling spark events in an engine includes determining for at least two engine revolutions in a four-stroke engine at least one characteristic of the primary coil voltage for a spark event, determining, based upon the characteristic of the primary coil voltage, which of the spark events is associated with a compression phase and which of the spark events is associated with an exhaust phase of engine operation, and providing spark events in subsequent engine revolutions that are associated with the compression phase of engine operation but not in revolutions associated with the exhaust phase of engine operation. In at least some implementations, the characteristic is the duration of the spark event as determined by changes in the primary coil voltage, and the characteristic may be that the duration that the primary coil voltage is above a threshold voltage.

The present invention provides a batteryless engine system comprising a first detection unit configured to detect a rotation speed of an internal combustion engine, a second detection unit configured to detect a voltage of a capacitor in which charges are accumulated, and a control unit operated by a power supplied from a generator and configured to control supply of a power from the generator to an injector, a fuel pump, and an ignition device based on the rotation speed detected by the first detection unit and the voltage detected by the second detection unit in a starting period of the internal combustion engine by a recoil starter.

In an ignition device, a proportion of a yoke end width defined as a distance from one end to another end of an end portion of each of a pair of yokes in the circumferential direction to a magnet width defined as a distance from one end to another end of a permanent magnet disposed on the outer circumferential surface of a flywheel, in the circumferential direction is in a range of 60% to 100%. Moreover, a proportion of the magnet width to a yoke interval between the pair of yokes is in a range of 95% to 100%.

A failure diagnosis device for an ignition circuit, comprising: an ignition plug; an ignition coil; a capacitor series connection including a high side capacitor and a low side capacitor; a switching-element series connection including a high side switching element and a low side switching element; an inter-terminal voltage detection unit for detecting an inter-terminal voltage of the capacitor series connection; an intermediate voltage detection unit for detecting an intermediate voltage at the connection point of the high side capacitor and the low side capacitor; and a determination unit for determining a failure location of the ignition circuit based on at least one of the inter-terminal voltage and the intermediate voltage.

A portable power generator with power monitor and control. The portable generator may include an alternator powered by an engine and configured to generate an alternator output, a first output receptacle coupled to the alternator output through a first switch, and a second output receptacle coupled to the alternator output through a second switch. The portable generator may further include a sensor unit configured to detect at least one output parameter of the first output receptacle. An electronic processor of the portable generator may be configured to receive first sensor signals indicating a measured quantity of the at least one output parameter of the first output receptacle and determine that the measured quantity exceeds a predetermined threshold. The processor may also be configured to disable the first output receptacle in response to determining that the measured quantity exceeds the predetermined threshold.

Provided is a device that detects a rotational speed variation amount of a multi-cylinder four-cycle engine, a rotation signal corresponding to each of the cylinders are generated once per one rotation of a crankshaft, an amount of time elapsed from a previous generation to a current generation of the rotation signal corresponding to each of the cylinders is detected as a rotation signal generation interval for each of the cylinders every time the rotation signal is newly generated, a difference between newly detected rotation signal generation interval for each of the cylinders and previously detected rotation signal generation interval for the same cylinders is calculated as a rotation signal generation interval change amount every time the rotation signal generation interval is detected, and a rotational speed variation amount of the engine is detected on the basis of the rotation signal generation interval change amount.

An ignition device includes a case having an opening and a bottom wall, a coil bobbin arranged in the case having a through hole, a first end and a second end, an ignition coil wound around the coil bobbin, a core made of magnetic material and projecting from the opening and from the bottom wall, and extending through the coil bobbin, a retainer having a ring portion and multiple leg portions extending from the ring, and a filling resin in the case. The core extends through the ring portion and the leg portions extend in between an inner surface of the coil bobbin and an outer peripheral surface of the core toward the bottom wall, and the case is filled with the filling resin in a manner that at least a part of the ring portion is not covered by the resin.

An ignition system includes a primary coil, a secondary coil, a first switch, a second switch, a third switch, a diode, and a switch control section. In the primary coil, a power supply is connected to a contact point between a first winding and a second winding. The secondary coil is magnetically coupled to the primary coil. The first switch is connected in series with the first winding. The second switch is connected in series with the second winding on the opposite side from the contact point. The third switch is connected in series with the second switch. The diode includes an anode connected between the second switch and the third switch and a cathode connected to the contact point. The switch control section controls opening and closing of each switch.

The present invention provides a batteryless engine system comprising a first detection unit configured to detect a rotation speed of an internal combustion engine, a second detection unit configured to detect a voltage of a capacitor in which charges are accumulated, and a control unit operated by a power supplied from a generator and configured to control supply of a power from the generator to an injector, a fuel pump, and an ignition device based on the rotation speed detected by the first detection unit and the voltage detected by the second detection unit in a starting period of the internal combustion engine by a recoil starter.

An ignition system for an internal combustion engine that utilizes a single primary coil and a single secondary coil to drive a pair of spark plugs. Current flowing in both a first direction and a second direction passes through the primary coil. The current flowing through the primary coil induces corresponding current in the secondary coil, which flows from the secondary coil to one of two spark plugs. Each spark plug is coupled to the secondary coil such that each of the two spark plugs receives current flowing only in a single direction. The current flowing through the ignition system can be from either a power source or created by the rotation of a flywheel having a series of magnet clusters.