Power Supply Board Section - Panasonic KX-FLB852CX Service Manual

KX-FLB852CX / KX-FLB852CXS

7.17. POWER SUPPLY BOARD SECTION

The power supply board circuit generates +3.3V, +6V, +12V and +24Vdc. It also supplies
AC voltage to the halogen heat lamp in the fuser unit.
The power supply board uses the switching regulator method.
AC
Input
Input
Circuit
A-B Voltage Wave Form
0
C-D Voltage Wave Form
0
E-F
G-H Voltage Wave Form
0
[Input Circuit]
The input current goes into the input rectifier circuit through the filter circuit. The filter circuit decreases the noise voltage and
the noise electric field strength.
[Rectifier Circuit]
The input circuit is rectified by D10 to D13 and charge C5 and C55 to make DC voltage. Then it supplies power to the converter
circuit.
[Kick-on Voltage Circuit]
Bias is applied to the Q1 gate via this circuit when the AC power is turned on and Q1 begins operating.
Block Diagram
A
Rectifier
+ +
Circuit
Kick-on
C5, C55
B
Voltage
Circuit
Triac
SCR1
Heat Lamp
D2
Surge
absorber
R5
Converter circuit
Circuit
R4
C
R3
Q1
R2
D
Control
Circuit
IC1
+
O.C.L
Over voltage
Error Detecting
Circuit
Photo Triac
Coupler PC2
262
T1
G
+
3.3V
Output
Circuit
Reg. IC
IC151
+
E
+
H
F
PC1
24V
3.3V
12V
6V
DGND
PGND
PWRDWN
HTRCTL