Abstract: A hand-held power tool has an electric drive motor having a drive shaft and a tool connected to the drive shaft and rotatably driven by the drive shaft. The drive motor has a control device that has correlated therewith at least a first operating curve and a second operating curve. The control device operates the electric drive motor in idle according to the first operating curve and operates the electric drive motor under load according to the second operating curve. The first operating curve covers the low power range at low speed and the second operating curve covers a large power range at high speed.

Abstract: A two-stroke engine has a cylinder with a combustion chamber delimited by a reciprocating piston, wherein the piston drives in rotation a crankshaft, and wherein a spark plug projects into the combustion chamber and ignites a fuel/air mixture. The two-stroke engine further has devices for supplying fuel and combustion air to the combustion chamber and a control unit that determines the ignition timing based on an ignition map. The ignition map indicates the ignition timing as a function of the engine speed for at least one first and one second operating states and for at least one first and one second engine speed ranges. The engine is controlled in that for an engine cycle the ignition timing is set in the second operating state at least within the first engine speed range based on the engine speed and on the number of engine cycles since the last combustion.

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 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: A power tool has a drive unit arranged in a tool housing. The drive unit has an internal combustion engine with a cylinder provided with a combustion chamber. A spark plug is arranged at the cylinder. A piston is connected to a crankshaft and reciprocates within the cylinder and delimits the combustion chamber. A central control unit controls the drive unit and has a microprocessor and an ignition control unit, wherein the central control unit is connected by the ignition control unit to the spark plug and triggers a spark at the spark plug as a function of a rotary speed of the crankshaft at an appropriate ignition timing. A data storage device is connected to the central control unit. An energy supply unit provides electric energy. An interface enables, from outside the tool housing, external data access to data of the central control unit.

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: A hand-held power tool has a drive motor driving a tool and a generator. One or more heating devices having one or more heating elements are provided. The generator supplies the one or more heating devices with energy. A control device controls a power supplied to the one or more heating elements as a function of at least one operating parameter of the drive motor.

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: A hand-held power tool has an electric drive motor having a drive shaft and a tool connected to the drive shaft and rotatably driven by the drive shaft. The drive motor has a control device that has correlated therewith at least a first operating curve and a second operating curve. The control device operates the electric drive motor in idle according to the first operating curve and operates the electric drive motor under load according to the second operating curve. The first operating curve covers the low power range at low speed and the second operating curve covers a large power range at high speed.

Abstract: A magnet wheel (1) for an internal combustion engine, especially a drive motor (2) for a portable handheld work apparatus includes a hub (4) for fixing to a crankshaft (5) of the drive motor (2) and a magnet carrier (6) having at least one magnet holder (7) provided peripherally on the magnet wheel (1). The magnet carrier (6) is a sheet-metal packet (9) of lamella-like layered plates (8). The sheet-metal packet (9) is layered modular-like from at least two differently configured profiled sheet-metal piece types (10, 11, 12). At least one profiled sheet-metal piece type (10) is configured as an arm plate (13) with a hub section (14) as part of the hub (4) as well as an arm section (15) which extends from the hub section (14) radially outwardly up to the region of the magnet carrier (6). At least one additional profiled sheet-metal piece type (11) is configured as a centrifugal mass sheet-metal piece (16) which lies essentially radially outwardly in the peripheral region of the magnet carrier (6).

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: A magnet wheel (1) for an internal combustion engine, especially a drive motor (2) for a portable handheld work apparatus includes a hub (4) for fixing to a shaft (5) of the drive motor (2) and a magnet carrier (6) having at least one magnet holder (7) provided peripherally on the magnet wheel (1). The magnet carrier (6) is a sheet-metal packet (9) of lamella-like layered plates (8). The sheet-metal packet (9) is layered modular-like from at least two differently configured profiled sheet-metal piece types (10, 11, 12). At least one profiled sheet-metal piece type (10) is configured as an arm plate (13) with a hub section (14) as part of the hub (4) as well as an arm section (15) which extends from the hub section (14) radially outwardly up to the region of the magnet carrier (6). At least one additional profiled sheet-metal piece type (11) is configured as a centrifugal mass sheet-metal piece (16) which lies essentially radially outwardly in the peripheral region of the magnet carrier (6).

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: A hand-held work tool has a housing with a carburetor heater and a grip heater. An internal combustion engine is mounted in the housing and has a crankshaft and an ignition system. The ignition system has a pole wheel with permanent magnets fastened sequentially at a periphery of the pole wheel in the circumferential direction. Charge armatures are mounted in the housing and close the magnetic circuit between neighboring permanent magnets. The charge armatures have legs and excitation coils mounted on the legs. Upon rotation of the pole wheel, the permanent magnets generate an electric current in the excitation coils, wherein a first set of excitation coils is combined to a first partial generator and connected to an electric circuit of the carburetor heater and a second set of the excitation coils is combined to a second partial generator and connected to an electric circuit of the grip heater such that the electric current is supplied respectively to the carburetor heater and the grip heater.