Abstract: A method and system for detecting a predefined level of resistance in motor activated drive systems for activating devices such as roller shutters, rolling gates, jalousies, awnings and movie screens in a predetermined direction or path. The method includes means for sensing predetermined characteristics of the electric motor when the electric motor is activated to move the drive in the predetermined path and detecting a predefined change in the motor characteristics due to the blockage or resistance. The electric motor is deactivated when a predefined level of resistance is detected along the predetermined path which blocks movement of the drive by the electric motor in the predetermined direction for a predetermined time period.
Type:
Grant
Filed:
November 13, 1995
Date of Patent:
April 10, 2001
Assignee:
Elero Antriebs- Und Sonnenschutz-Technik GmbH