High Speed Length Controllers Instruction Manual
Model: 315D | 322D
© Aurora Scientific, 2020 VER. 1.00
page 11
4.3
Tuning
1.
Ensure the power switch located on the front panel of the electronics box is turned OFF. Attach
the power cable to the back of the box and to the appropriate power.
2.
Firmly attach the cable between the electronics box and motor using the captured screws on the
cable. Place the arm on the motor such that it swings about the same distance to either side of
the motor centerline. Tighten the arm's clamp. For model 315D the arm is factory installed.
*** CAUTION: Lethal voltages are exposed during this procedure. ***
Use caution whenever the top cover of the electronics box is removed.
3.
Remove the Phillips-head screw located on the back panel along the top edge of the electronics
box. Slide the top cover back and remove it from the box. Connect oscilloscope CH1 to LENGTH
OUT and connect oscilloscope CH2 to TP17 (Current). Connect the function generator to LENGTH
IN.
** Note: If only a slight adjustment to the dynamic tuning of the
system is required then skip down to step (10) below. **
4.
Locate potentiometers R25, R28, R31 and R59 and then turn them counter clockwise (CCW) 25
turns or until a click is heard.
5.
Turn the front panel LENGTH OFFSET to the center of its range (5 turns from either stop).
6.
Disable servo by moving the Inhibit switch to the STOP position. Turn on the power switch.
7.
Observe LENGTH OUT while moving the arm back and forth. LENGTH OUT should change
positively for clockwise (CW) rotation.
8.
Turn R25 and R59 2 turns CW.
9.
While holding the motor and arm such that the arm is prevented from moving an excessive
amount, move the Inhibit switch to the RUN position. The FAULT lamp may light up for a few
seconds and then turn off. When it does the arm should now want to sit close to the center of
the range.
10.
Apply a 1-volt peak-to-peak square wave to LENGTH IN at 75Hz. While carefully monitoring
LENGTH OUT with the oscilloscope synced to the function generator, slowly turn R28 CW until
the motor begins to respond to the signal input. Continue to turn R28 CW until the waveform
looks under damped. Monitoring both the LENGTH OUT signal and the motor current signal
during the tuning procedure makes it easier to tune the system because small oscillations tend to
be amplified on the current trace.
