Andreas Stihl Ag Co. Kg

Franz Mandl

Georg Maier

Eberhard Schieber

Heinrich Leufen

Robert Boeker

Joerg Praeger

The invention relates to an ignition device for triggering an ignition spark at a spark plug by way of an ignition generator. The latter includes a magnet wheel, which has two permanent magnets arranged at a spacing from each other in the peripheral direction and a magnetic yoke. The magnetic yoke carries a charging coil which charges an ignition capacitor, a primary coil and a secondary coil connected to the spark plug. During every passing of a permanent magnet, a voltage is induced in the coils, wherein, in order to trigger the ignition spark, the ignition capacitor is discharged via a switch element. In order to avoid an unwanted ignition at the bottom dead center of the piston, a device for reducing the voltage that occurs at the spark plug is provided.

Ignition device for a two-stroke engine

The invention relates to an arrangement for identifying a switching position of a switch (on an internal combustion engine in a handheld work apparatus. An energy source for supplying power to an inductive electrical load is provided, it being possible to connect the load to the energy source in order to be switched on and off via a controller. The switch is arranged in a voltage branch which is connected in parallel with the inductive load and in which a zener diode is also connected. The zener diode is activated or inactivated via the switch as a function of the switching position of the switch. The amplitude of the switch-off voltage, which is induced when the inductive load is disconnected, is limited by the zener diode, so that it is possible to read from the magnitude of the amplitude whether the switch is closed or open.

Arrangement for identifying a switching position of a switch on an internal combustion engine in a handheld work apparatus

The invention relates to a portable hand-guided work apparatus having an internal combustion engine () for driving a work tool (). A combustion chamber () is formed in a cylinder () of the engine () and is delimited by a piston () which drives a crankshaft () in rotation. A spark plug () is held in the cylinder () and is driven by an ignition module () to ignite a compressed air/fuel mixture in the combustion chamber () to drive the piston (). A short circuit line () is provided on the ignition module () for switching off the ignition. The short circuit line () is configured as a bus line () in order to make available, in a simple manner, a plurality of further operating parameters to the ignition module. An external control apparatus () and/or sensors () are connected to the bus line (). The ignition module (), as master, controls data traffic on the bus line () and permits a data communication on the bus line () only when a minimum crankshaft angular distance (A, B) is present at an ignition time point (Z, Z) of the ignition module ().

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Fellbach, Germany

Franz Mandl