Abstract: A method for operating a permanently excited synchronous motor of a hand-held working device includes the steps of: sensorlessly determining a position variable representative of a position of a rotor of the synchronous motor at a standstill; determining a direction variable for a continuous rotation of the rotor from standstill in a direction on the basis of the determined position variable such that an absolute value of an attainable torque that can be generated by the synchronous motor during its sensorless actuation for the rotation in the direction is greater than an absolute value of a breakaway torque limit of the working device; and sensorlessly actuating the synchronous motor on the basis of the determined direction variable for the rotation in the direction.

Abstract: Benzoylamides of the general formula (I) are described as herbicides. In this formula (I), B, X1 and X2 represent N, O or S(O)n. R, Ra, Rb and Rx represent radicals such as hydrogen, halogen, (C1-C6)-alkyl, halo-(C1-C6)-alkyl, (C1-C6)-alkyloxy and cyano.

Abstract: A method for ascertaining, without an encoder, a rotational angle position of the rotor of a brushless DC motor, includes the steps of: detecting a voltage induced in a stator of the brushless DC motor; checking whether the voltage induced in the stator is lower than a threshold value; and if the induced voltage is lower than the threshold value, then ascertaining an initial rotational angle position of the rotor based on an Indirect Flux detection by Online Reactance Measurement, and subsequently updating the rotational angle position proceeding from the calculated initial rotational angle position using at least one continuous test signal.

Abstract: A ceramic component is formed of at least one stack of two or more layers of one-directional non-woven carbon fiber fabrics embedded in a ceramic matrix containing silicon carbide and elemental silicon. All adjacent layers within the at least one stack directly adjoin each other. The at least one stack has a minimum thickness of 1.5 mm perpendicularly to the plane of the layers. The ceramic matrix permeates substantially the entire component.

Abstract: The present invention provides a method and a device to determine the rotor field angle of an asynchronous machine even during the magnetising phase, in which the rotor field of a rotor of the asynchronous machine is built up. The asynchronous machine can then be actuated in a controlled operating mode even during the magnetising phase. The startup properties of the asynchronous machine can thus be improved, the magnetising phase of the asynchronous machine is shortened and it is possible to set a desired torque even during the magnetising phase.

Abstract: The invention relates to a welding robot for resistance welding, which exhibits a welding tongs (21), a welding current generator (1) connected to the welding electrodes (24, 25) of the welding tongs (21), for supplying the welding electrodes (24, 25) with electric energy during the resistance welding, and an industrial robot. The industrial robot comprises a robot arm (2) and a robot control device (9) for moving the robot arm (2). The welding tongs (21) is connected to the robot arm (2) and the robot control device (9) is connected to the welding current generator (1) and a tongs drive (26, 27) of the welding tongs (21).

Abstract: A method for determining state variables of an electric motor for driving a motor vehicle, comprising the procedural steps: measuring (102, 104) data (103, 105) which comprise information about a current state of vehicle components (10, 12, 30, 40); converting (110) the measured data (103, 105) into data (111) related to the electric motor (10) using a vehicle model of the motor vehicle (1); evaluating (120) the data (111) related to the electric motor (10) using a machine model of the electric motor (10) for determining at least one first state variable (121) of the electric motor (10); determining (130) at least one second state variable (131) of the electric motor (10) using a sensorless method; comparing and assessing for plausibility (140) the at least one first and the at least one second state variable (121, 131).

Abstract: A method for determining state variables of an electric motor for driving a motor vehicle, comprising the procedural steps: measuring (102, 104) data (103, 105) which comprise information about a current state of vehicle components (10, 12, 30, 40); converting (110) the measured data (103, 105) into data (111) related to the electric motor (10) using a vehicle model of the motor vehicle (1); evaluating (120) the data (111) related to the electric motor (10) using a machine model of the electric motor (10) for determining at least one first state variable (121) of the electric motor (10); determining (130) at least one second state variable (131) of the electric motor (10) using a sensorless method; comparing and assessing for plausibility (140) the at least one first and the at least one second state variable (121, 131).