Canon Color imageRUNNER LBP5280, Service Manual, Page: 41 / 284

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Technical Reference > Controller System > Power Supply > Other function
Technical Reference > Controller System > Power Supply > Other function
Power Supply
■ Low-voltage power supply
The low-voltage power supply and the fixing power supply convert AC power from the power
receptacle into DC power to cover the DC loads.
• Low-voltage power supply:
Generates DC power required in the printer
• Fixing power supply:
Supplies AC power to the low-voltage power supply
Controls the fixing heater temperature in the fixing assembly
+3.3V
Protection
circuit
Rectifying
circuit
Zero
crossing
circuit
+24V
ZEROX
PSREM24V
Low-Voltage Power Supply
Power Switch
SW3001
AC input
+24V generation
circuit
Noise filter
Noise filter
Fuse
FU2801
DC Controller
Fixing power supply
Fixing
control
circuit
Fuse
FU2901
Power Supply Unit
+3.3V
generation
circuit
Power switch
control circuit
For low pressure power, insert the AC power in the inlet, switch the power ON, and it will
start. The AC power gen3.3V in the fixing power, +24V in the low pressure power,
and supplies to the host machine.
F-2-23
■
Other function
Protective function
The low-voltage power supply has a protective function against overcurrent and overvoltage
to prevent failures in the power supply circuit. If there flows an overcurrent or overvoltage, the
low-voltage system automatically cuts off the output voltage.
If the DC voltage is not being supplied from the low-voltage power supply, turn off the power
switch and unplug the AC power cord. Do not turn the power switch on again until the root
cause is found.
In addition, two fuses in the fixing power supply protect against overcurrent. If overcurrent
flows into the AC line, the fuses blow and cut off the AC power.
Power-save mode
The power-save mode reduces power consumption of the printer.
When the low-voltage power supply receives the POWER SAVE (REM24V) signal from the
DC controller, it stops the power supply from the +24V generation circuit.