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Verfügbare Sprachen
Verfügbare Sprachen
5. P.W.B. Power Supply Circuit (Switching Power Circuit)
@
220V AC (50Hz) is full-wave rectified by rectifier diode DB1 to become the DC power supply.
@
The voltage generated in the primary winding of the switching transformer is transmitted to the
secondary windings via the core of the transformer by switching Q701 at high speed.
The voltages
according to each winding are generated at each output of the secondary circuits.
@
The voltages generated in the secondary windings are rectified by D704 ~ D710 and smoothed by
C707 ~ C715.
@(15-E)
We
toni 2A
D(15-F)
oo
RIOIA
(®(15-E)
3.15A FUSE
is
Tori 3A
Om
Or
R702A
ie
O(15-E)
——o
~
Qo
~
iy
al
Tora
|
x
Ny
AC 220V
50Hz
Ch)
@(15-D)
=
)(15-D).
zCT15A
Ba
R702
@15- ~D)
®(15-D)
Le
+12V
es =| BERET aps
yaDT05k
709)
eat
Q701A
Q702A
-5V
ie
kaos
267074 ; RI36A i=)
(5-D)@
R709A
R711A
ie
C706A
(5-D)©®
PQ7OIA
Peat
Fig. 5-1
REG2A ie
* The oscillation period T varies in different operation
modes (loads).
Voltage at
* Use a tester to measure each output voltage and check
that they are as specified to locate defects.
If no output voltage is generated, it is assumed that
Q701, Q702, ZD701,
R702, 3.15A fuse, etc. are
defective.
X It is recommended that you disconnest connectors
CN27 between the MAIN and I/F P.W.B. to check the
Oscitation'period T
operation when the switching voltage circuit is defective.
Fig. 5-2
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