Power Source Pwb - Kyocera Mita FS-6020 Service Manual

2-3-1 Power source PWB

AC
Power
power
switch
F1
source
SW1
F2
Fixing
heater
lamp
control
circuit
CR1
PC4
Fixing
heater
lamp
The power source PWB consists of the switching regulator section that is the main part, other zero cross signal detection
circuit and fixing heater control circuit. The switching regulator circuit consists of the noise filter circuit, inrush current limit/
rectification circuit, switching control circuit, 5 V DC rectification/smoothing output circuit, 24 V DC rectification/smoothing
circuit and overcurrent/overvoltage detection circuit, and this circuit converts the AC power input to the 5 V DC and 24 V DC
power source by the switching operation and outputs it to the engine/high voltage PWB. The zero cross signal detection
circuit detects the 0 V point (zero cross) of the AC wave form and outputs to the engine/high voltage circuit, and the engine/
high voltage PWB outputs the fixing heater lamp ON signal (HEATON) to the fixing heater lamp control circuit based on the
timing of zero cross signal and controls the AC power loading to the fixing heater lamp.
Power source PWB
Inrush current limit/rectification
smoothing circuit
Noise
TH1,TH2
filter
circuit
(L1, L2)
C7
Zero cross
Switching
signal
control
detection circuit
circuit (IC1)
(D8, D9, PC3)
Pulse
Figure 2-3-1 Power source PWB block diagram
24 V DC rectification/
T1
smoothing output circuit
D1
D200
Q1
5 V DC rectification/
smoothing output circuit
D100
PC1
PC2
Rear cover
interlock
switch
+24V1
SW2
C201
C202
C203
GND
+5V1
C101
C102
C103
GND
Overcurrent/
overvoltage
detection circuit
ZCROSS
+24V2
HEATON
FS-6020
2-3-1