Service manual

Section I: Imagesetter
Functional Analysis 2-37
The voltage comparator is structured as an oscillator with the frequency controlled
by the sensor. This sensor, a capacitor, varies its capacitance in relation to the
amount of moisture in its environment. As the moisture level increases, the sensor
capacitance also increases causing the oscillator frequency to decrease.
2.15.5 Interface Connections
The controller module connects by cable to the imagesetter through the supply
sensor driver module (SSDM) board. The cable connects three humidifier functions
(sensing and controlling) to the SSDM.
2.15.6 Software Functionality
The humidifier option enables and disables via the operator contol panel (OCP)
configuration screen (also see user documentation). Pressing the humidifier icon on
this screen displays an expanded view of both the option’s current and alternate
state (i.e., enabled or disable). The screen highlights (bold type) the current state.
When the humidifier option is not installed, the humidifier key shows the humidi-
fier disabled icon.
2.15.7 Humidifier PC Board: LED Descriptions
CR1 +24 V to the fan. LED “On” = module enabled
CR3 This LED should be on whenever power is applied to the humidifier PC
board.
CR7 This LED comes on when the water value solenoid is energized, opening
the water value and allowing the water reservoir to fill.
Figure 2-21 Humidifier PC board, with connectors (J1 and J2)
and LED’s (CR1, CR3, and CR7)
J1 J2
CR1
CR3
CR7