External And Controls System; Power Supply; Protective Functions - Canon MF4500 Series Service Manual

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Technical Overview > External And Controls System > Power Supply > Protective Functions

External And Controls System

Power Supply

■ Power Supply
Protection
Power
Circuit
Supply
Assembly
24V
5V
Generating
Circuit
Engine Controller PCB
24V 3.3V
3.3V
5.5V
DC/DC
Converter
1.0V
Main Controller PCB
2 Technical Overview > External And Controls System > Power Supply > Protective Functions
3.3V
Fixing Assembly
5V
Laser Scanner Unit
24V
Motor Driver PCB
3.3V
5.5V
FAX-NCU PCB
24V
24V
Solenoid
3.3V
LAN
3.3V
Control Panel Unit
5.5V
3.3V
ADF Unit
5.5V
+Reader Unit
F-2-41

■ Protective Functions

● Power protective function
Low voltage power circuit carries the overcurrent preventive function against and overvoltage
preventive function that block the voltage output automatically to prevent the power circuit
brokerage when the overcurrent or overvoltage occur due to load errors such as short circuit
etc.
Thus, when the DC power cannot be output from the low voltage circuit, the protective
function against overcurrent or overvoltage may be working. Turn OFF the power switch (SW1)
to fix load errors and turn ON the switch again (see note 1).
Also the circuit carries the 2 fuses (FU101, FU102) as a preventive function (see note 2). The
fuses blow to block the power supply when overcurrent occurs in AC line.
1. When restoring the low voltage power after protective function is activated, leave it for
2 minutes or more from turning off the switch or plugging out before turning ON.
2. 200V series products carry FU101 fuse only.
● Safety function
The host machine equips the function of stopping 24V of fixing assembly and the high voltage
power unit to avoid users and engineers from getting burned or electric shock.
When the cartridge door is opened, the interlock switch (SW501) is turned off and 24V
supplied to fixing assembly and the high voltage power unit is shut.
Engine controller CPU determines the door open when each interlock switch is turned OFF.
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