41
Ic
Current monitor scale (A/V) :
3.75
8.3Adjusting the motor speed (velocity mode only)
Adjusting the speed is done by adjusting the input gain trimmer of the tacho feedback:
- Increasing/decreasing the feedback gain will decrease/increase the speed.
It is also possible to increase/decrease the command gain (change the fix resistors of the differential amplifier) in order to increase/decrease the speed.
Best performance is achieved when the feedback gain is as close as possible to its maximum value. Therefore, the final adjustment should yield with Ki of the tacho input trimmer over 0.8.
8.4Adjustment of the IxR compensation
If you do not use this feature, skip this chapter.
After following all the instructions in 7.3, you may improve the speed stability in various load conditions by performing the following procedure:
a. Run motor at 2/3 of nominal speed. b. Apply nominal load.
c. Increase IxR compensation (CW rotation of gain 1 - trimmer T7) until motor's speed reaches the no load speed.
d. Notice that a high compensation may result in unstable operation of the amplifier.
Reducing the DC and AC gains of the error amplifier by increasing C1 and R5 is recommended. The final values depend on the type of motor and mechanical load, so optimum results will be achieved by the empirical method.
ISP - Rev 6/95
