A method and a system for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft are disclosed. An absolute angular position of the crankshaft related to a top dead center position of a piston in a combustion chamber of the ICE is determined. Electric power is delivered to the ETM at a first level to rotate the crankshaft. Electric power is then delivered to the ETM at a second level greater than the first level when the piston reaches a predetermined position before the TDC position. Fuel is injected in the combustion chamber after the piston has passed beyond the TDC position. The fuel is then ignited. In an implementation, the ICE is started in less than 110 degrees of rotation of the crankshaft.

An electric turning machine (ETM) operatively connected to an internal combustion engine (ICE) is operated as a motor with a first control strategy and as a generator with a second control strategy. In the first control strategy, electric power is delivered from a power source to the ETM selectively through at least one transistor of an electrical converter. After switching from the first control strategy to the second control strategy, the ETM delivers electric power to an accessory selectively through the at least one transistor of the electrical converter.

An electric turning machine (ETM) operatively connected to an internal combustion engine (ICE) is operated as a motor with a first control strategy and as a generator with a second control strategy. In the first control strategy, electric power is delivered from a power source to the ETM selectively through at least one transistor of an electrical converter. After switching from the first control strategy to the second control strategy, the ETM delivers electric power to an accessory selectively through the at least one transistor of the electrical converter.

A hand-held power tool comprising an internal combustion engine (4), a working tool (6), a centrifugal clutch (8), and a control system (10) is disclosed. The engine (4) has a clutch-in speed, above which the engine (4) drives the working tool (6). The control system (10) comprises a rotation speed sensor (12), and a speed limitation controller (14), which is configured to limit an engine speed at a limitation speed below the clutch-in speed. It is active or activated during a starting procedure of the internal combustion engine (4). The control system (10) is configured to deactivate the speed limitation controller (14) upon sensing at least one acceleration at a level above the limitation speed and sensing at least one deceleration at a level above the limitation speed, such that the engine (4) is rotatable above the limitation speed to drive the working tool (6).

In at least some implementations, an auxiliary power supply in an ignition system for a light-duty combustion engine includes a first auxiliary winding and a second auxiliary winding coupled in parallel with the first auxiliary winding such that both windings are arranged to provide power to an auxiliary load. The first auxiliary winding may include a greater number of turns than the second auxiliary winding. A ratio of the number of turns in the first auxiliary winding to the number of turns in the second auxiliary winding may be between 1.5:1 and 10:1, the first auxiliary coil and the second auxiliary coil may have between 50 and 2,000 turns, and the first auxiliary coil and the second auxiliary coil are formed from wire between 25 and 45 gauge.

A starting device for a combustion engine includes a housing relative to which a rope pulley, a spring housing and an entrainer can rotate about a rotation axis. A coupling unit produces a rotationally-fixed connection between the rope pulley and the spring housing in response to a rotational movement of the rope pulley in a starting direction. The spring housing has a spring receiving space for a tension spring and is connected to an entrainer by the spring. The coupling unit has a first coupling element and a second coupling element, which interact at a contact location which is at a spacing (d) to the rotation axis and is at least as large as the maximum spacing (c) of the tension spring to the rotation axis.

A starting device for a combustion engine includes a housing relative to which a rope pulley, a spring housing and an entrainer can rotate about a rotation axis. A coupling unit produces a rotationally-fixed connection between the rope pulley and the spring housing in response to a rotational movement of the rope pulley in a starting direction. The spring housing has a spring receiving space for a tension spring and is connected to an entrainer by the spring. The coupling unit has a first coupling element and a second coupling element, which interact at a contact location which is at a spacing (d) to the rotation axis and is at least as large as the maximum spacing (c) of the tension spring to the rotation axis.

A startup assistance device, which assists startup of an internal combustion engine in which fuel is supplied from an electronically controlled fuel injection device and ignition is performed by an ignition device, includes a recoil starter which is driven by manpower and which performs cranking for starting up the internal combustion engine, an electric rotary machine which adds torque to a crankshaft of the internal combustion engine during at least one of a startup period of the internal combustion engine using the recoil starter and a standby period before the startup period, a power source unit which supplies power to the electric rotary machine, and a control unit which controls the magnitude and time of the torque output by the electric rotary machine.

A method for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft comprises energizing an absolute position sensor adapted for providing an indication of an angular position of a rotor of the ETM and applying a current to the ETM to generate a sufficient torque to rotate the crankshaft.

A method for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft comprises energizing an absolute position sensor adapted for providing an indication of an angular position of a rotor of the ETM and applying a current to the ETM to generate a sufficient torque to rotate the crankshaft.