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8. Once limits have been set, re-apply dc power and adjust input test circuit (analog or
raise/lower) for range value above upper limit. When upper limit is reached, main gear
will stop rotating and output pressure will hold constant at value of desired limit.
Do not attempt to turn main gear or driveshaft by hand to
reach a limit. The force generated in this manner can
easily damage the gear teeth and limit tangs. Always use a
dc test input signal to drive the main gear through its
range.
9. If limit values are not at desired points, continue to experiment with tangs until correct
positions can be found.
10. When adjustments are complete, disconnect test setup and recheck board configuration
as required. Replace cover and restore unit to normal operating status.
5.4 CALIBRATION TEST SETUP
The calibration of the Remote Set Regulator will require a laboratory bench setup. The
setup of Figure 5-2 is used for Analog models, while that of Figure 5-3 is used for
Raise/Lower models.
In Figure 5-2, the Analog model uses a precision 1 - 5 volt test source to provide an ad-
justable input signal. In Figure 5-3, the Raise/Lower model uses a switch test circuit con-
sisting of two pushbutton switches that apply dc power to either the Raise or Lower inputs.
As long as a switch is pressed, the output will be raised or lowered assuming continuous dc
input configuration.
From this point on, the test setups of Figures 5-2 and 5-3 are identical. A digital multimeter
(DMM #1) is connected across test points TP3 and TP4 to monitor the voltage at the center
arm of the feedback potentiometer. The 250 ohm resistor and switch circuit is used to load
the current output circuit, while DMM #2,functioning as a milliammeter, measures the load
current.
On the pneumatic side, a constant supply pressure is applied to the pressure regulator as-
sembly. A precision test gauge monitors the pressure output signal. The pressure regulator
assembly of the unit does not have calibration adjustments. All adjustments are electrical.
5.5 CALIBRATION PRECAUTION
During calibration, the stepper motor will be driven to both ends of it operating range.
Since this movement is extremely slow, do not be tempted to run the unit up or down range
by manually forcing the main gear or driveshaft. Doing so can cause damage to the gear
teeth and the mechanical limit tangs. Always use a dc test input signal to reposition the
main gear and allow the Remote Set Regulator to balance itself out.
Service
** Caution **
5-4
CI-9110
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