SPRING AND DOOR OPEN POSITION
PULSE DISK
A pulse disk fitted to the drive shaft is used to detennine the door closed position. This
is achieved by the pulse counter calculating a series of holes around the circumference
of the disk, one of which is open. When the perimeter sensor locates the edge of the
notch the door operator stops the door.
PULSE COUNTER
The counter has three sensors. Two count the pulses and the disk direction, the other
senses the perimeter of the disk.
PULSE COUNTER
SPRING
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SPRING
When the power is switched on at the first time. the setting of the spring tension is made.
The spring tension detennines the torque on the shaft I.e. which is the force what keeps
the door closed. The torque needed depends on the weight and width of the door.
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