Panasonic KX-F1200 Service Manual And Technical Manual page 143

j KX-P i 200
15. SWITCHING POWER SUPPLY SECTION
Block Diagram
AC I_ A ' Circuit I
I Oircuitl IRectifier--'_Cl0_5
Converter
A-B Voltage Wave Form
C-D Voltage Wave Form
E-F
G_HVeltage Wave Form
SUB Printed
Circuit Board
IC101
Control ___
Circuit " -_
(MC101)
Over Current ._
Circuit _
F--,- 24 voutpu
tput CircuitJ
_ I
| O GND
D-C--DC +12v Output
Converter
Circuit _ +5V Output
t Error Detecting
Circuit |
[Input Circuit]
Input current goes into input rectifier circuit through filter circuit. Fitter circuit decreases noise terminal voltage and noise elec-
tric field strength.
[Rectifier Circuit]
Input current is rectified by D101 and charge C105 to make DC voltage, then supply power to converter circuit.
Voltage is supplied to control IC's kick-on voltage through R102 and R103. Inrush current is limited by thermistor TH101.
[Converter circuit]
The converter circuit of this power supply circuit is called fly back converter.
We explain the operation of this circuit with the simple circuit.
O
Ei
O
T101
p-,
-,€
Q101
CONTROL CIRCUIT
D201
- 143 -
: 0
Eo
+
7:,Z
P...PRIMARY WINDING
S...SECONDARY WINDING
B...CONTROL WINDING
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