23
GLENTEK Inc. 208 Standard Street, El Segundo, California 90245, U.S.A. (310) 322-3026
SMA7215 MANUAL
9.
Do not adjust Tach Gain or Compensation for the rest of the calibration procedure.
10. With battery box still connected at J1-3 and J1-4 for single-ended input, set battery box for a
known DC voltage. Adjust Signal Gain (RV7) to obtain the desired motor velocity.
11. If the motor is rotating in the wrong direction for a given input polarity, remove power and
reverse both the motor leads and the tach leads.
12. Remove battery box, and repeat step 3.
13. Calibration complete. Reconnect signal wires.
6.4 Calibration of the Current Mode Amplifier:
The amplifier in this configuration, receives an analog, bi-polar input command which is
proportional to the required motor current(motor torque). The following potentiometers (pots) will
be set during calibration: (Note: RV1-RV5 are single turn pots and RV6-RV13 are 12-turn pots.)
Pots
Name of Pot
Notes
RV1
Loop Gain
LOOP GAIN
Used to shut off uncalibrated amplifiers. When the loop gain is
fully CCW, no current is delivered to the motor.
RV6
Differential Gain
DIFF SIG GAIN
Sets the input voltage to current ratio for differential signal input.
RV7
Signal Gain
SIG GAIN
Sets the input voltage to current ratio for single-ended signal input.
RV8
Balance
BAL
Used to null any offsets in system.
RV13
Current Limit
I LIMIT
Sets maximum motor current. Shipped set at full CCW
(minimum current limit).
Note: RV2, RV3, RV4 and RV5 are factory set and should not be adjusted. Adjusting these pots
voids warranty.
PROCEDURE:
1.
Apply main power and fan power.
2.
Slowly turn Loop Gain(RV1) pot CW. Motor should be stopped or turning slowly. Set Balance
(RV8) for 0V at J1-6 (MTR I).
3.
Connect oscilloscope to J1-6 (MTR I) and battery box to J1-3 (J1-4 is common for both). The
voltage on J1-6 is a function of motor current: 1V=5A. While applying a step input voltage,
adjust Current Limit (RV13) for desired peak current. If desired peak current cannot be
achieved with Current Limit pot full CW, increase either the input signal or Signal Gain (RV7)
for single-ended input.
