Power Supply Pcbs; 1 ] Low-Voltage Power Supply Pcb - Brother IntelliFax-3550 Service Manual

3.6

Power Supply PCBs

[ 1 ] Low-voltage power supply PCB
The low-voltage power supply uses the switching regulation system to generate DC power
(+5V and +24V) from a commercial AC power supply for the driver circuits. The +5V source
is fed to the logic, control panel, sensors, CCD unit, etc.; the 24V source is fed to the motors,
solenoid, fans, LED array, and the high-voltage power supply PCB.
The low-voltage power supply also feeds AC power to the heater of the fixing unit.
Lightning
Fuse
Surge
Absorber
Line
Rectifier
Filter
Low-voltage Power Supply Circuit
III – 28
Heater
Circuit
Feedback
Switching
Circuit
24V
Detector
5V
Regulation
Circuit
(Heater)
Thermal
Fuse
FU lamp
(Driver circuits)
24V
5V