Abstract: A device for cleaning interdental spaces includes a housing that forms a handle. The device also includes a brush holder for holding an interdental brush, and a drive device which is configured to generate rotational and translational movement of the brush holder and/or of an interdental brush held in the brush holder.

Abstract: The combining of two technically contrasting functions of “safe stopping” and “braking by armature short-circuiting” is served by using two means for pulse inhibition to block the respective current valves in the event of a fault by interrupting respective supply voltages for driving the control valves of the upper bridge arm and those of the lower bridge arm. For the purpose of braking by armature short-circuiting, the stator winding of a three-phase AC motor is short circuited in the event of a fault, or else operationally, by virtue of the fact that all current valves of a bridge arm can be switched on, a voltage being provided for switching on these current valves via a logic unit when the respective supply voltage for driving the current valves of this bridge arm are interrupted by the means for pulse inhibition.

Abstract: The present invention makes possible a safety function for speed monitoring in the case of all induction machines operated on an inverter without a sensor system, in that a determined setpoint stator frequency value (&phgr;5*) is limited and monitored in a two-channel mode in two systems with approximate redundancy, deriving from this in each system respective sets of control signals for the electrical valves of the inverter, which can be compared with one another in two systems of monitoring electronics. In the event of fault detection, two-channel switching off takes place. The circuit arrangement according to the invention can additionally be subjected to enforced dynamization.

Abstract: The combining of two technically contrasting functions of “safe stopping” and “braking by armature short-circuiting” is served by using two means for pulse inhibition to block the respective current valves in the event of a fault by interrupting respective supply voltages for driving the control valves of the upper bridge arm and those of the lower bridge arm. For the purpose of braking by armature short-circuiting, the stator winding of a three-phase AC motor is short circuited in the event of a fault, or else operationally, by virtue of the fact that all current valves of a bridge arm can be switched on, a voltage being provided for switching on these current valves via a logic unit when the respective supply voltage for driving the current valves of this bridge arm are interrupted by the means for pulse inhibition.

Abstract: The present invention makes possible a safety function for speed monitoring in the case of all induction machines operated on an inverter without a sensor system, in that a determined setpoint stator frequency value (&phgr;S*) is limited and monitored in a two-channel mode in two systems with approximate redundancy, deriving from this in each system respective sets of control signals for the electrical valves of the inverter, which can be compared with one another in two systems of monitoring electronics. In the event of fault detection, two-channel switching off takes place. The circuit arrangement according to the invention can additionally be subjected to enforced dynamization.

Abstract: Disclosed is an apparatus for operating a converted-fed asynchronous electric motor which comprises a flux computer for determining the position of the flux vector from the input values for the stator voltage provided by said motor by solving all the electrical quantities of the Park equations describing said motor in a given position of the rotor axis, taking into account the parameter values corresponding to the rotor resistance and the stator resistance of said motor whereby signals corresponding to the position of the flux vector and belonging to a solution, can be tapped from said flux computer; a converter control unit coupled to said flux computer and said convertor rectifier respectively, forming the control quantities for driving the converter rectifier from the determined position of the flux vector and from the nominal input values which fix the components of the stator current vector parallel and perpendicular to the flux vector.