Electronic brush switch-off unit for network-dependent braked electric motor, has electric motor disconnected from network by semiconductor switch when predetermined braking time is exceeded

摘要

The unit has a control electronics system (5) with a controller for monitoring a braking operation. Braking time is monitored during the braking operation such that the pressure of brushes (6) on a collector and the current flow via the collector are not sufficient for a predetermined braking time during placing of a brush pressure spring on a brush holder. An electric motor is disconnected from a network by a semiconductor switch (3) when the predetermined braking time is exceeded. The controller has a program for monitoring the run-down time of the motor during the braking operation.