The drive system uses a thyristor current regulator (1) for revs regulation of an asynchronous drive motor (4), with controlled braking provided by supplying the stator winding with a DC signal. A current rectifier (2) connected in an AC bridge circuit acts as an active filter in the driving mode of the drive motor and provides the braking energy in the DC braking mode.

Drive system for lifting gears and tool machines

A braking circuit for machine tools, which is fitted with a plurality of AC motors, particularly fast-running AC motors, contains a rectifier (9), to whose input AC is applied, an electronic switch (1), connected in series with at least one field winding (13) of the AC motor, and a freewheeling diode (12), connected in parallel with the field winding (13). In this arrangement, the DC voltage supplied by the rectifier (9) is applied to the field winding (13) through the electronic switch, in a controlled on/off mode. In order to increase the possible power factor of the current flowing through the field winding (13) with a defined root-mean-square level, a transformer (2) is connected to the input side of the rectifier (9) and the output voltage emitted to the rectifier (9) is smaller than that which is supplied into the transformer (2).

Schroecker Rainer Dipl Ing

Papers

Braking circuit for tool machines fitted with several alternating current motors, especially high speed alternating current motors

Bremsschaltung fuer mit mehreren wechselstrommotoren, insbesondere schnellaufenden wechselstrommotoren ausgeruesteten werkzeugmaschinen