Manual Number 9018205 Revision F, April 1, 2021
16
Display Dimming Adjustment (Type 2 units)
For Type 2 units, the brightness range of the clock can be adjusted before or after installation
using the control buttons on the front of the unit. With the unit in either LOCAL or UTC mode,
simply pressing the
–
or
+
buttons will adjust the brightness setting. The CH93 will
automatically detect and adjust the brightness control method that is currently active. If the
automatic photocell is active, ADJ1 is displayed. It is recommended to set the photocell
adjustment level in a dark or night-time cockpit environment. If the unit is receiving a dimming
input voltage, ADJ2 is displayed. If used, both should be set to the appropriate preference.
Once set, the photocell and lighting bus adjustments will be saved in the clock configuration.
If the brightness of the clock needs to be increased or decreased during flight, this can be
performed in either LOCAL or UTC mode using the same procedure previously described.
Refer to Figure 4.3 for detailed instructions on adjusting dimming for Type 2 units (for both
photocell and lighting bus display dimming modes).
Figure 4.1
Figure 4.2
Photocell Dimming Adjustment
Bus Voltage Dimming Adjustment
(-5 unit shown)
(-5 unit shown)
Figure 4.3
Dimming Adjustment (Type 2 units only)