| 摘要 |
<p>A door, comprising articulated slats 10 raisable into tracks 14, is moved by cables winding on or off drum 12 rotated via belt 16 by electric motor 18. The motor is slidable at 30 to adjust belt tension or to slacken the belt to remove drive. Disclosed motor control includes monitoring of the rate of change in the motor load in response to an obstruction, counting the number of door operations, and the connection of stand-by batteries across a power supply when charging and in series when powering the motor.</p> |
