Abstract: A method for operating a machine tool (1), in particular an angle grinder, comprising a tool (3) that can be rotatably brought into operative connection with a driven shaft (7), the machine tool (1) having a drive device (4) for actuating the driven shaft (7), a control device (8) for actuating the drive device (4) and at least one sensor device (9, 10) operatively connected to the control device (8). The sensor device (9, 10) is used to determine whether a device (3, 11) is operatively connected in a defined manner to a defined region of the machine tool (1), the control device (8) enabling operation of the drive device (4) only if the query result is positive. A machine tool (1) for carrying out a method of this kind is also described.

Abstract: An abrasive disk has one or more layers in which abrasive grains are embedded. Embedded in one layer is a sensor for detecting an original periphery of the abrasive disk that has been altered by wear. The sensor has at least one closed conductor loop which is arranged at a radial distance from the original periphery such that, when the original periphery is worn by more than the radial distance, the conductor loop is interrupted. A transponder emits a radio signal indicative of whether the conductor loop is closed or interrupted.

Abstract: 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.

Abstract: RNA encoding an immunogen is co-delivered to non-immune cells at the site of delivery and also to immune cells which infiltrate the site of delivery. The responses of these two cell types to the same delivered RNA lead to two different effects, which interact to produce a strong immune response against the immunogen. The non-immune cells translate the RNA and express the immunogen. Infiltrating immune cells respond to the RNA by expressing type I interferons and pro-inflammatory cytokines which produce a local adjuvant effect which acts on the immunogen-expressing non-immune cells to upregulate major histocompatibility complex expression, thereby increasing presentation of the translated protein to T cells. The effects on the immune and non-immune cells can be achieved by a single delivery of a single RNA e.g. by a single injection.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a portable hand-guided work apparatus having an internal combustion engine (10) for driving a work tool (5). A combustion chamber (12) is formed in a cylinder (11) of the engine (10) and is delimited by a piston (13) which drives a crankshaft (14) in rotation. A spark plug (16) is held in the cylinder (11) and is driven by an ignition module (20) to ignite a compressed air/fuel mixture in the combustion chamber (12) to drive the piston (13). A short circuit line (21) is provided on the ignition module (20) for switching off the ignition. The short circuit line (21) is configured as a bus line (30) in order to make available, in a simple manner, a plurality of further operating parameters to the ignition module. An external control apparatus (23, 24) and/or sensors (25, 26) are connected to the bus line (30).

Abstract: The invention relates to a portable hand-guided work apparatus having an internal combustion engine (10) for driving a work tool (5). A combustion chamber (12) is formed in a cylinder (11) of the engine (10) and is delimited by a piston (13) which drives a crankshaft (14) in rotation. A spark plug (16) is held in the cylinder (11) and is driven by an ignition module (20) to ignite a compressed air/fuel mixture in the combustion chamber (12) to drive the piston (13). A short circuit line (21) is provided on the ignition module (20) for switching off the ignition. The short circuit line (21) is configured as a bus line (30) in order to make available, in a simple manner, a plurality of further operating parameters to the ignition module. An external control apparatus (23, 24) and/or sensors (25, 26) are connected to the bus line (30).