Kyocera FS-1900 - Power Supply Unit

4-37
FS-1900
(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.
Figure 4-3-15 Power supply unit circuit block diagram
FET
Switching
control
circuit
Zero cross
signal
generation
circuit
Power
switch
Current
fuse
Noise
filter
circuit
Transformer
24 V DC
rectifier/
smoothing
circuit
Enargy-
saving
circuit
Photo-
coupler
Photo-
coupler
Photo-
Tr iac
Tr iac
ZCROSS
FDDR
EXITPAP*
FDFUL
THERM
HEATON*
FUDR
+24V1
SLEEP*
+5V1
GND
GND
Heater
lamp
AC
input
Rectifier
circuit
5 V DC
rectifier/
smoothing
circuit
Power supply unit
Fuser
board
Engine
board
Thermal
cutout
Thermistor
Paper full
sensor
Exit sensor
Face up/down
solenoid
+
Over
voltage/
current
detection
circuit
+5V1
+24V