Switching between full-speed rotation and half-speed rotation is controlled as described below.
1) Full-speed control
When the CPU on the DC controller outputs a fan full speed signal (FAN_FULL), the fan drive voltage switching circuit supplies a +24 V fan drive voltage to turn
the heat exhaust fan at the full speed.
2) Half-speed control
When the CPU on the engine controller outputs a fan half speed signal (FAN_HALF), the fan drive voltage switching circuit supplies a +16 V fan drive voltage to
turn the heat exhaust fan at the half speed.
Fan Control Sequence
E805-0000 (Main body fan error)
When the cooling fan of the main body starts, the fan lock detection signal (FAN_LOCK) has been held at the "H" level for longer than the prescribed time.
9.3 Power Supply System
9.3.1 Power Supply
When the main power switch (SW1) is turned on, AC power is supplied to the low-voltage power supply circuit in the power supply PCB.
The low-voltage power supply circuit supplies +3.3 V, +5 V, and +24 V to operate the machine.
+24 V is supplied to the motors, fan, electromagnetic clutch, solenoid, etc. +5 V and +3.3 V are supplied to the sensor, etc.
There are two types of +24 V voltages: +24 V which is normaly supplied from the low voltage power supply and +24 VR which is cut off when the front cover or
the left door is opened. The +24 VR also plays the role of a door open detection signal (DOPEN). This signal allows the CPU to detect that the front cover or the
left door has opened.
Power supply PCB
Option power supply PCB (option)
Main power switch (SW1)
Front cover switch (SW2)
Left door switch (SW3)
Power switch ON/
Copy start key ON
Going out of sleep mode
Heat Discharge Fan
Fixing Drive Motor
Generates DC power from AC power.
Generates DC power from AC power for the options.
Supplies AC power to the power supply PCB.
Detects opening/closing of the front cover and cuts off +24 VR.
Detects opening/closing of the left door and cuts off +24 VR.
: Full speed (+24V)
: Half speed (+16V)
Power switch OFF/
Going into sleep mode