Patent ID: 6541930
Filing Date: 2003-04-01
Classification: E05F,E05Y,H02H,Y10S

Abstract:
A method for regulating an electric-motor-driven adjusting device having a safety circuit for reversing or stopping a drive motor, comprising the steps of:regulating an actual value via a closed-loop control circuit to a set-point value, the actual value and set-point value being signals proportional to actual and set-point of the rpm or load of the drive motor; said regulating including detecting a deviation of the actual value from the set-point value by a comparison member of the control circuit to change the rpm or load of the drive motor to reduce the deviation; and sensing a value of the detected deviation exceeding a threshold value to activate the safety circuit to reverse or stop the drive motor; said actual value being a signal having an actual frequency proportional to the rpm of the drive motor and which is compared with a set-point frequency as the set-point value to produce a signal representing the phase difference between the set-point frequency and the actual frequency by which the safety circuit is activated when the phase difference signal exceeds the threshold value.