| 摘要 |
An electric motor 44a moves a suspension device 28 along a headrail 10 or pole towards and away from a stop 48 to open and close the blind or curtain. An automatic controller 12 is provided which detects a monotonic increase in current to the motor 44a associated with drive from the motor 44a being taken up by the springs 50 as the stop 48 is reached and interrupts current to the electric motor 44a when the increase in motor current is detected. The controller also stores the position of the suspension device 28 when the increase in current is detected and drive to the electric motor 44a during subsequent operation of the system is then regulated to interrupt current to the motor before the suspension device 28 hits the stop 48 again. |
