Abstract: A device for sensing an alternating current includes a circuit board on whose surface is arranged a planar conductor path in which a current to be measured flows. Applied on the opposite surface of the conductor path is a planar coil in which the change in the current to be measured induces a voltage. The device is advantageously used in a converter having a direct-current voltage link circuit.

Abstract: A drive device regulates a servomotor to one of a predefined position, a predefined speed, and a predefined current setpoint value. A control module is connected upstream from the drive device. A non-volatile memory where motor-specific data is stored is arranged in the housing of the servomotor. The housing has a data output through which the motor-specific data can be read. The motor-specific data is transmitted over a data line over which the feedback signals delivered by a sensor associated with the motor are also transmitted.

Abstract: A safety device for a drive is includes a monitoring system which evaluates a value describing the operating state of the drive in order to ascertain whether an emergency operation should be started for the protection of the drive instead of normal operation. The monitoring system generates at least one first output signal for an actuating element that influences the power supply to the drive. In normal operation an a.c. signal is used as the output signal and in emergency operation a d.c. signal is used.

Abstract: For driving each power transistor of a three phase bridge rectifier for utilizing d.c. electric power for the control and energization of a motor, each individual power transistor is provided with an individual driver circuit supplied an individual power supply. Each power transistor in such a rectifier has a reverse voltage free wheeling diode connected between emitter and collector. Each individual driver circuit has its input control signal supplied through a galvanic isolation stage in the form of an optical coupler and the power supply has its input connection to a source of power galvanically isolated by a transformer, supplying a relatively high frequency for powering the rectifier of the driver power supply. The final driver stage utilizes Darlington transistor combinations of complementary types, one Darlington combination being supplied with negative voltage and the other being supplied with positive voltage, by the power supply rectifier.