Abstract: In a method for detecting an operating parameter of a power tool having an internal combustion engine with a cylinder, a piston delimiting a combustion chamber in the cylinder and driving a crankshaft supported rotatably in a crankcase, an intake supplying combustion air to the combustion chamber, an exhaust removing combustion gases from the combustion chamber, and a signal generator driven in rotation by the crankshaft emitting sequential alternating voltage signals, a period duration of the voltage signal is selected to correspond to the n-th portion of a crankshaft revolution with n greater than 2. The n-th portion of the crankshaft revolution provides a crankshaft angle interval. For each crankshaft angle interval at least one information is detected that represents a course plotted against the crankshaft angle. The course is scanned with regard to characteristic features that are correlated with an operating parameter of the power tool.

Abstract: An internal combustion engine has a combustion chamber having a spark plug arranged thereat. A crankcase supports a crankshaft. An intake for introducing fuel and combustion air into the combustion chamber is provided. An exhaust for exhausting combustion gases from the combustion chamber is provided. A piston is connected to the crankshaft and drives the crankshaft in rotation. A wheel member is connected to the crankshaft and rotates with the crankshaft. An alternator driven by the crankshaft supplies electric power to a consumer. The alternator is arranged within a radial boundary of the wheel member and external to the crankcase. The alternator has a stator and a rotor, wherein the crankshaft penetrates the stator and wherein the rotor is fixedly connected to the wheel member.

Abstract: An ignition device for a motor unit with an internal combustion engine provided with a piston, a combustion chamber with a spark plug, a crankshaft driven by the piston, an intake port supplying combustion air to the combustion chamber, an exhaust for removing combustion gases from the combustion chamber, a signal generator driven by the crankshaft and emitting for one crankshaft revolution an alternating voltage signal, has an ignition unit that triggers a spark at the spark plug at a preselectable timing. The ignition unit is a module separate from the motor unit. An alternating voltage signal generated by the signal generator is supplied to the ignition unit as an information signal sufficient for operating the internal combustion engine. The alternating voltage signal is supplied to a first unit for energy processing and to a second unit for processing information for control of the internal combustion engine.

Abstract: An ignition circuit is for an internal combustion engine in a handheld portable work apparatus. A combustion chamber (4) is configured in the cylinder (3) of the engine (1) which is delimited by a piston (5) driving a crankshaft (7). A pole wheel (10) revolves with the crankshaft (7) and is assigned to an induction loop (13). The pole wheel periodically changes the magnetic flux in the induction loop. An ignition capacitor (16) is charged by a charge coil (14) of the induction loop and is discharged via a discharge circuit (15) via an ignition coil (17). The ignition coil is connected to a spark plug (19) projecting into the combustion chamber. For achieving a powerful ignition spark, the discharge of the ignition capacitor is prevented by an rpm evaluation circuit (23) when the rpm curve (30) exhibits an rpm change (?n) which exceeds a pregiven threshold value.

Abstract: An ignition device for a motor unit with an internal combustion engine provided with a piston, a combustion chamber with a spark plug, a crankshaft driven by the piston, an intake port supplying combustion air to the combustion chamber, an exhaust for removing combustion gases from the combustion chamber, a signal generator driven by the crankshaft and emitting for one crankshaft revolution an alternating voltage signal, has an ignition unit that triggers a spark at the spark plug at a preselectable timing. The ignition unit is a module separate from the motor unit. An alternating voltage signal generated by the signal generator is supplied to the ignition unit as an information signal sufficient for operating the internal combustion engine. The alternating voltage signal is supplied to a first unit for energy processing and to a second unit for processing information for control of the internal combustion engine.

Abstract: An internal combustion engine has a combustion chamber having a spark plug arranged thereat. A crankcase supports a crankshaft. An intake for introducing fuel and combustion air into the combustion chamber is provided. An exhaust for exhausting combustion gases from the combustion chamber is provided. A piston is connected to the crankshaft and drives the crankshaft in rotation. A wheel member is connected to the crankshaft and rotates with the crankshaft. An alternator driven by the crankshaft supplies electric power to a consumer. The alternator is arranged within a radial boundary of the wheel member and external to the crankcase. The alternator has a stator and a rotor, wherein the crankshaft penetrates the stator and wherein the rotor is fixedly connected to the wheel member.

Abstract: In a method for detecting an operating parameter of a power tool having an internal combustion engine with a cylinder, a piston delimiting a combustion chamber in the cylinder and driving a crankshaft supported rotatably in a crankcase, an intake supplying combustion air to the combustion chamber, an exhaust removing combustion gases from the combustion chamber, and a signal generator driven in rotation by the crankshaft emitting sequential alternating voltage signals, a period duration of the voltage signal is selected to correspond to the n-th portion of a crankshaft revolution with n greater 2. The n-th portion of the crankshaft revolution provides a crankshaft angle interval. For each crankshaft angle interval at least one information is detected that represents a course plotted against the crankshaft angle. The course is scanned with regard to characteristic features that are correlated with an operating parameter of the power tool.

Abstract: The invention is directed to a method for operating a two-stroke engine having a cylinder in which a combustion chamber is formed and which includes devices for metering fuel and supplying combustion air as well as an ignition device for igniting a mixture in the combustion chamber. In the method, fuel and combustion air are supplied to the engine and the mixture in the combustion chamber is ignited. The combustion chamber is delimited by a piston which drives a crankshaft rotatably journalled in a crankcase. A control is provided which controls the metering of fuel and the ignition of the mixture in the combustion chamber. In the method, the two-stroke engine is controlled in at least one operating state so that the number of combustions is less than the number of revolutions of the crankshaft in the same time interval.

Abstract: An ignition circuit is for an internal combustion engine in a handheld portable work apparatus. A combustion chamber (4) is configured in the cylinder (3) of the engine (1) which is delimited by a piston (5) driving a crankshaft (7). An electromagnetic induction loop (13) and a pole wheel (10) are provided. The pole wheel (10) revolves with the crankshaft (7) and is assigned to the induction loop (13). The pole wheel (10) periodically changes the magnetic flux in the induction loop (13). An ignition capacitor (16) is charged by a charge coil (14) of the induction loop (13) and is discharged via a discharge circuit (15) via an ignition coil (17). The ignition coil (17) is connected to a spark plug (19) projecting into the combustion chamber (4). For achieving a powerful ignition spark, the discharge of the ignition capacitor (16) is prevented by an rpm evaluation circuit (23) when the rpm curve (30) exhibits an rpm change (?n) which exceeds a pregiven threshold value.

Abstract: The invention is directed to a method for operating a two-stroke engine having a cylinder in which a combustion chamber is formed and which includes devices for metering fuel and supplying combustion air as well as an ignition device for igniting a mixture in the combustion chamber. In the method, fuel and combustion air are supplied to the engine and the mixture in the combustion chamber is ignited. The combustion chamber is delimited by a piston which drives a crankshaft rotatably journalled in a crankcase. A control is provided which controls the metering of fuel and the ignition of the mixture in the combustion chamber. In the method, the two-stroke engine is controlled in at least one operating state so that the number of combustions is less than the number of revolutions of the crankshaft in the same time interval.

Abstract: An internal combustion engine is provided, and has a throttle element mounted in the intake channel of the engine so as to be pivotable, via a throttle shaft, between an idling position and a full-load position. An abutment is fixedly connected with the throttle shaft. In the idling position, the abutment rests against a stop element that is fixed in position on the intake channel. The stop element is adjustable and establishes the idling position of the throttle element. The abutment forms, with the stop element, a switch that is actuated in the idling position of the throttle element.

Abstract: An internal combustion engine is provided, and has a throttle element mounted in the intake channel of the engine so as to be pivotable, via a throttle shaft, between an idling position and a full-load position. An abutment is fixedly connected with the throttle shaft. In the idling position, the abutment rests against a stop element that is fixed in position on the intake channel. The stop element is adjustable and establishes the idling position of the throttle element. The abutment forms, with the stop element, a switch that is actuated in the idling position of the throttle element.

Abstract: A heating device is provided for a handle of a portable implement, especially a chain saw, a brush cutter, trimmer or the like. At least one heating element is disposed in the handle for heating the handle. The heat-conducting element is connected to the heating element and serves for a distribution of heat within the handle and for a transfer of heat to the handle.

Abstract: The invention is directed to a handheld, portable tool such as a chain saw equipped with an internal combustion engine mounted in an engine housing. The engine has a carburetor defining an air-intake channel. A heating element is provided which is electrically connected to the generator of the chain saw and mounted on the carburetor in the region of the air-intake channel. The heating element has a positive temperature coefficient and a predetermined temperature region thereby preventing the carburetor housing and the throttle flap from heating to a temperature above a predetermined value. The heating element and the way it is mounted prevents icing at the carburetor in cold weather thereby enabling the engine to run uninterruptedly and uniformly especially when the engine idles.