KB Electronics KBRG-212D - Manual (Page 29)

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10.7 Offset (OFFSET) - This trimpot determines the amount of bias in the forward or reverse
direction. The trimpot is factory set to provide approximately zero offset, which means
neither the forward nor the reverse speed is favored. See Figures 26A and 26B.
FIGURE 26A –
OFFSET TRIMPOT POSITION
FIGURE 26B –
OFFSET TRIMPOT ADJUSTMENT
a
(%)
MAIN SPEED
POT
ROTATION -100
-100
(%) SPEED
100 b
100
c
CURVE OFFSET
(a) None (b) Forward (c) Reverse
10.8 Scale (SCALE) – The Scale potentiometer is used in conjunction with jumper J8
(Section 7.5, on page 22) and the MAX Trimpot (Section 10.2, on page 26). This allows
for fine adjustments of the analog input signal within the 0 – 10V or 0 – 15V ranges. In
addition, the trimpot has an adjustment range of ±5 to ±25V. See Figures 27A and 27B.
,
Example: Using a 90 V DC motor, and with jumper J8 to the 10V position. Adjust the
Main Speed Potentiometer (Section 6.8, on page 16) to maximum clockwise (CW)
position. At this point, the motor will be running at full speed. Adjust the SCALE trimpot,
3 turns in a counter-clockwise (CCW) position, until the voltmeter reads approximately
87 V DC (Production voltage setup).
FIGURE 27A –
SCALE TRIMPOT POSITION FIGURE 27B – SCALE TRIMPOT ADJUSTMENT
Note: Factory setting for this
Potentiometer will be equivalent to
87 V DC for a 90 V DC motor.
Refer to the example below.
INPUT VOLTAGE
5 10 25
VOLTS
180/90