Abstract: An ignition circuit for a combustion engine has an ignition coil and a control unit for the coil. The coil and the control unit are included in a common component as an ignition module. The module is supplied with voltage by a generator driven by the engine. A spark plug and the coil form a power circuit which includes a line segment to a reference potential outside the module. A sensor detects data of the engine and the output of the sensor is supplied to the module. The sensor is supplied with voltage via a sensor circuit. The sensor circuit and the power circuit use the line segment as a common connection to the reference potential, so that for a defect of the line segment, a missing connection to the reference potential in the high voltage circuit is recognized via the change of the sensor output signals.

Abstract: In a method for operating a power tool with a diagnostic device, wherein the power tool has an internal combustion engine, a generator as an energy supply, and an electronic control unit, wherein a diagnostic device is connectable to the electronic control unit, and wherein the electronic control unit has an operating mode and a diagnostic mode, a non-uniform voltage signal is supplied by the generator as an energy supply and a uniform voltage signal is supplied by the diagnostic device as an energy supply. The electronic control unit evaluates the voltage signal that is being supplied as an energy supply and switches to diagnostic mode when the voltage signal is the uniform voltage signal supplied by the diagnostic device.

Abstract: A hand-held working apparatus has an internal combustion engine having a crankshaft which is driven in rotation. The crankshaft drives at least one tool of the working apparatus via a centrifugal clutch. The working apparatus has a device for determining the speed of the internal combustion engine and a control device which controls the internal combustion engine. It is provided that the profile of the speed of the internal combustion engine is evaluated by the control device, and that the engagement speed of the centrifugal clutch is determined from the profile of the speed of the internal combustion engine. A method of operation is also provided.

Abstract: A connector system (1) includes a plurality of connectors (39 to 45) which each have a plug and a counter plug. Each plug has a plurality of receptacles (29, 30) for contacts and each counter plug has a plurality of receptacles (29, 30) for counter contacts. In at least one receptacle (29, 30) of each plug, a contact is arranged and in at least one allocated receptacle (29, 30) of each counter plug, an allocated counter contact is arranged. In at least one of the connectors (39 to 45), at least one receptacle of a plug does not have a contact. In the allocated receptacle (29, 30) of the counter plug, a coding element is arranged which prevents the insertion of a contact into this receptacle (29, 30) of the counter plug.

Abstract: In a method for operating a power tool with a diagnostic device, wherein the power tool has an internal combustion engine, a generator as an energy supply, and an electronic control unit, wherein a diagnostic device is connectable to the electronic control unit, and wherein the electronic control unit has an operating mode and a diagnostic mode, a non-uniform voltage signal is supplied by the generator as an energy supply and a uniform voltage signal is supplied by the diagnostic device as an energy supply. The electronic control unit evaluates the voltage signal that is being supplied as an energy supply and switches to diagnostic mode when the voltage signal is the uniform voltage signal supplied by the diagnostic device.

Abstract: A connector system (1) includes a plurality of connectors (39 to 45) which each have a plug and a counter plug. Each plug has a plurality of receptacles (29, 30) for contacts and each counter plug has a plurality of receptacles (29, 30) for counter contacts. In at least one receptacle (29, 30) of each plug, a contact is arranged and in at least one allocated receptacle (29, 30) of each counter plug, an allocated counter contact is arranged. In at least one of the connectors (39 to 45), at least one receptacle of a plug does not have a contact. In the allocated receptacle (29, 30) of the counter plug, a coding element is arranged which prevents the insertion of a contact into this receptacle (29, 30) of the counter plug.