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CHAPTER 2
2 - 12
D. Low-Voltage Power Supply Circuit
1. Outline
The AC voltage input from the inlet is converted into the DC voltage in the rectification circuit, transformer, and power
supply circuits. Then, the DC voltage is supplied to the printer as +24VDC, +5VDC, and +3.3VDC.
When the cartridge door is opened, the door switch (SW301) is turned OFF. This cut OFF the +24VU supplied to
the high-voltage circuit. At the same time, the DOSNS signal goes “L”, causing the CPU to determine that the cartridge
door is opened and to stop the printer.
The AC voltage is supplied to the fixing heater through the fuse (FU101), noise filter, relay, and triac.
The +3.3VDC is supplied to the ICs on the engine controller PCB, BD PCB, and interface controller PCB.
The +5VDC is supplied to the ICs on the engine controller PCB, laser/scanner driver PCB, interface controller PCB,
and sensors.
The +24VDC is supplied to the high-voltage power supply circuit, main motor, scanner motor, and solenoids.
Figure 2-2-6
+24VU
+5V
+5V
+5V
+24V
+24V
+5V
+24V
+5V
+24V
+24V
+3.3V
+3.3V
Inlet
Fixing heater
Main motor
Solenoid
High-voltage
power supply
circuit
Noise
filter
Interface
controller
PCB
Laser/scanner
unit
+24V
power
supply
circuit
+5V
power
supply
circuit
Engine Controller PCB
Sensors
DOSNS
+3.3V
power
supply
circuit
Sensor
(T501)
Main
motor
drive
circuit
Noise
filter
Rectifi-
cation
circuit
Transformer
Overvoltage
detection
circuit
Overcurrent
detection
circuit
Door switch
(SW301)
CPU
Relay
Triac
(IC501)
Control IC
Fuse
(FU101)
Fuse
(FU102:100-127V only)
Summary of Contents for Laser Shot LBP-1120
Page 4: ...PREFACE P 2 ...
Page 54: ...2 35 CHAPTER 2 Figure 2 6 1 4 1 3 2 J1 2 1 20 19 J2 IC2 IC1 IC3 IC4 ...
Page 107: ...APPENDIX A 2 ...