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Chapter 6   Principles of Operation
Epson AcuLaser C2900N
Revision B
Confidential
3.9 Electrical
3.9.1 Major functions
- FAN (PL8.1.1)
Dissipates heat out of the printer to prevent the printer from overheating.
-SWITCH
The SWITCH turns ON/OFF the AC power supply of the printer.
- Low Voltage Power Supply (LVPS:PL8.2.1)
The LVPS is provided in two types, 120V and 240V.
Supplies AC power from the power source to the Fuser Unit heater and generates and supplies sta-
ble low voltage DC power used for the logic circuit, etc.
LVPS contains control circuit for the heater of the Fuser Unit, in addition to the power circuit.
- Machine Control Unit (MCU:PL8.2.13)
Controls printing operation based on the communication with the print controller and information 
from the sensor/switch.
Major functions are as follows:
• Communication with the ESS.
• Receive of information from the sensors or switches.
• Control of Motor in DRIVE ASSY MAIN and DRIVE ASSY SUB.
• Distributing low voltage DC power output from LVPS to each component
• Control of ROS ASSY
- High Voltage Power Supply (HVPS:PL4.1.19)
Supplies high voltage to the following parts in the TRANSFER ASSY and Developer to perform 
charging, development, and primary transfer.
• BCR
• BTR
• Developer
- PWBA EEPROM (PL8.2.16)
Information unique to the printer is stored.
- Electronic Sub System (ESS:PL8.1.7)
The ESS connected to the MCU controls the entire system (Diagnostic, Interface and Image pro-
cessing).
- HUMIDITY SENSOR (SENSOR HUM:PL8.2.7)
HUMIDITY SENSOR reads the temperature/humidity within the printer and converts the values to 
voltage values.
- OPERATOR PANEL (CONSOLE ASSY PANEL:PL1.2.3)
OPERATOR PANEL displays the state of the printer using LED. 
- INTERLOCK SWITCH (HARN ASSY INTERLOCK:PL8.2.5)
INTERLOCK SWITCH is a switch that cuts the +24VDC power supply to the HVPS or Motor, etc. 
upon the opening of the Front Cover.