Power Supply Board - Kyocera FS-1020D Service Manual

2FM

2-3-3 Power supply board

The power supply board provides the AC power input and DC power and outputs. The high voltage bias generator circuit is
mounted on a separate board. A simplified schematic diagram is shown below.
AC
Power
Current
input
switch
fuse
(SW1) (F1)
Current
fuse
(F2)
Heater
lamp
Triac
(TRA1)
Thermal
cutout
2-3-8
Power supply unit
Noise D1
filter
circuit
(L1)
C5
+
Switching/
FET
Over
(Q1)
current
detection
circuit
Figure 2-3-6 Power supply board circuit block diagram
Transformer
(T1)
24 V DC
rectifier/
smooth-
ing circuit
5 V DC
rectifier/
smooth-
ing circuit
Photo-
Over voltage
coupler
detection
(PC1) circuit
Photo-
coupler
(PC5)
Photo-
Transistor
coupler
(Q121)
(PC4)
Zero cross signal
detection circuit
Photo-
Triac
(PC2)
Exit
EXITN
sensor
(PC3)
+24V1
SLEEP
24 V DC
shutoff
FAN
circuit
+24V1
+5 V
PGND, SGND
THERM
ZCROSS
+24V2
HEATN
Cooling fan
Fuser
thermistor