Power Supply Unit - Kyocera FS-1900 Service Manual

(4) Power supply unit

The power supply unit produces DC power outputs from the AC input. The high voltage bias
generator circuit is mounted on a separate unit.
A simplified schematic diagram is shown below.
Power
Current
AC
switch
fuse
input
Heater
lamp
Thermal
cutout
Thermistor
Figure 4-3-15 Power supply unit circuit block diagram
Power supply unit
Rectifier
Noise
circuit
filter
circuit
+
FET
Zero cross
signal
generation
circuit
Triac
Paper full
sensor
Transformer
Enargy-
saving
circuit
Switching
control
5 V DC
circuit
rectifier/
smoothing
circuit
Photo-
coupler
Photo-
coupler
Photo-
Triac
+5V1
Exit sensor
4-37
24 V DC
rectifier/
smoothing
Over
circuit
voltage/
current
detection
circuit
EXITPAP*
+24V Fuser
board
Engine
board
SLEEP*
+24V1
GND
+5V1
GND
ZCROSS
HEATON*
THERM
FDFUL
FDDR
FUDR
Face up/down
solenoid
FS-1900