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18
Date: 2018-11-28
Duty-cycle
When the unit is continually operated for more than 30 minutes at full load, speed and high
ambient temperatures, the below duty-cycle (DC) limitation will need to be considered.
The duty-cycle (DC) is the fraction of a period where the motor is active. The duty-cycle is
commonly expressed as a percentage or ratio. Its described as the period it takes for a system to
complete an on-and-off cycle.
Thus, a 10% duty-cycle means the system is on 10% of the time and off 90% of the time
. The “on
time”
for a duty-cycle is normally related with a cycle length in time. E.g. a max duty-cycle of 50%
(30 min. ON / 30 min. OFF), means that the motor may not be active for more than 30 minutes
every hour, or after 5s ON the motor must be OFF for 5s if continually operated for more than 30
minutes.
Synchronized movements of multiple Mini Roll Downs
If several Mini Roll Downs are installed to perform synchronized movements, the best result is
achieved by using a fading 16 bit position. By nature, there is a slight deviation in performance of
the motors, and some motors have a slightly higher maximum speed than others.
Like when fading light, the positions of the different Mini Roll Downs should be faded, and the
Mini Roll Downs will tend to follow that fade. When fading the positions:
1.
The speed channel should be a set to 100 % to gain the highest possible speed.
2.
The position channel should be added as a 16 bit channel and not just the MSB on channel
1.
3.
The speed of the fade needs to be slower than the maximum speed, so the motors have
speed enough to perform the movement.
If the fade of the positions is too fast, the Mini Roll Downs will move at the maximum speed, and
you will see the difference in the motor speed.
If the fade is to slow the Mini Roll Downs will move
–
stop
–
move
–
stop, when the position
changes, thus giving a discontinuous movement.
