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Sanyo C14EA80D User Manual

Sanyo C14EA80D
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CIRCUIT
DESCRIPTION
1.POWER
SUPPLY
The
power
supply
circuit
of
the
EC2-A
chassis
is
composed
of
a
rectifier
smoothing
circuit,
an
oscillation
circuit,
a
control
circuit
and
an
output
rectifier
circuit.
The
AC
input
voltage
is
full-wave
rectified
by
the
rectifier
smoothing
circuit,
and
an
unstable
DC
voltage
is
generated
at
both
terminals
of
the
smoothing
capacitor
C307.
This
voltage
is
input
to
the
oscillation
circuit.
The
oscillation
circuit
is
provided
with
a
blocking
oscillator
circuit
that
switches
the
switching
transistor
Q313
ON
and
OFF,
and
an
oscillation
frequency
and
a
duty
square
wave
pulse
are
generated
in
the
input
windings
according
to
operation
of
the
control
circuit.
A
square-wave
pulse
whose
size
is
dependent
on
the
turn
ratio
of
the
input
and
output
windings
is
obtained
in
the
output
winding.
This
is
rectified
in
the
output
rectifier
circuit,
and
the
desired
DC
voltage
is
obtained.
2.IF
&
DEFLECTION
(TDA8361)
The
IF
output
signal
from
the
tuner
passes
through
the
SAW
filter,
and
it
is
input
to
pin45
and
pin46
of
1C101.
The
signal
input
to
the
IC
passes
through
the
IF
amplifier,
video
detection
and
video
amplifier
circuits
and
is
output
from
pin7
as
a
composite
video
signal.
And
after
this
signal
is
converted
to
impedance
at
Q122,
supplies
to
the
video
and
chroma
amplifier
stages.
The
output
signal
from
pin7
passes
through
the
6.0MH2z(I)/5.5MHz(B/G)
trap
circuit
of
X151,
and
it
is
input
to
pin5
of
1C101.
The
signal
input
to
the
IC
passes
through
the
SIF
amplifier,
FM
detector,
external
audio
switch
and
audio
output
circuit,
and
it
is
then
output
from
pin50
as
audio
drive
signal.
The
sync.-separation
circuit
separates
the
video
signals
applied
to
pint3
or
pin15
to
vertical-
and
horizontal-sync.
signals
respectively.
The
horizontal
oscillator
requires
no
external
components
and
is
fully
integrated.
The
oscillator
is
always
running
when
the
Start-pin36
is
supplied
with
8V.
Horizontal
drive
signal
is
output
from
pin37.
VR401
is
for
adjustment
of
the
horizontal
centering.
The
separated
vertical-sync.
signal
from
sync.
separation
circuit
passes
through
the
vertical-
separation
circuit,
and
applied
to
trigger
divider
circuit.
The
horizontal
oscillation
pulse
and
input
vertical
sync.
pulse
are
monitored
by
the
trigger
divider
circuit,
and
Switching
50Hz
and
60Hz
system,
the
vertical
amplitude
automatically
adjusted
for
50Hz
and
60Hz.
The
output
signal
from
the
trigger
divider
is
triggered
vertical
oscillation
circuit
consisting
of
C401,
R402
and
pin42,
and
vertical
drive
pulse
is
output
from
pin43.
VR431
is
for
changing
the
amount
of
AC
feedback
applied
to
pin41
and
for
adjustment
of
the
vertical
amplitude.
3.VIDEO
CHROMA
&
R.G.B.
(TDA8361)
The
composite
video
signal
output
from
the
pin7
of
IC101
passes
through
Q122/Q124,
and
it
is
supplied
to
pini3.
The
external
video
signal
output
from
SCART
is
supplied
to
piniS.
The
video
signal
input
to
pin13
or
pints
is
separated
to
luminance
(Y)
signal
and
chroma
signal
in
1C101.
These
pins
are
used
in
common
with
H/V-sync.
separation
input.
The
peaking
of
Y
signal
is
adjusted
by
DC
voltage
of
pini4.
(“SHARPNESS”
control)
The
chroma
signal
is
divided
into
R-Y and B-Y
chroma
signals,
demodulated
in
1C101,
and
output
from
pin30
(R-Y)
and
pin31
(B-Y).
These
chroma
signals
pass
through
the
1H
delay
line
circuit
(IC270),
and
they
are
input
to
pin29
(R-Y)
and
pin28
(B-Y).
These
R-Y/B-Y
signals
pass
through
RGB
matrix
circuit
and
RGB
selector
circuit
of
1C101.
The
internal
RGB
signals
are
generated
in
RGB
matrix
circuit
and
the
RGB
selector,
consisting
linear
amplifiers,
clamps
and
selects
either
the
internal
RGB
signals
or
the
external
OSD
signal
from
pin23(G).
In
this
stage,
the
OSD
signal
which
is
switched
by
blanking
signal
from
pin21
is
superimposed
into
internal
RGB
signals.The
colour
gain
is
controlled
by
DC
voltage
of
pin26.
(“COLOUR?”
control)
The
contrast
control
voltage
present
at
pin25,
and
the
brightness
control
voltage
present
at
pint7
controls
DC
level
of
RGB
signals.
The
RGB
signals
are
finally
buffered
before
being
available
at
the
RGB
output
pins
[pin20
(R),
pini9
(G),
pin18
(R)].
4.AUDIO
OUTPUT(AN5265)
The
audio
signal
output
from
pin50
of
IC101
is
input
to
pin2
of
1C171
and
passes
through
the
pre-amplifier
circuit
and
drive
circuit,
after
which
it
is
input
to
the
audio
amplifier.
The
audio
amplifier
is
an
SEPP
(single-ended,
push-pull)
OTL
type
and
output
to
pin8
to
directly
drive
the
speaker.
5.VERTICAL
OUTPUT
(LA7832)
An
IC
(LA7832)
is
used
for
the
vertical
output
circuit
in
this
chassis.
The
vertical
drive
pulse
from
pin43
of
10101
is
input
to
pin4
of
1C451.
This
pulse
drives
1C451,
and
vertical
scanning
is
performed.
In
the
first
half
of
scanning
a
deflecting
current
is
output
from
pin2
and
passes
through
the
following
path:
Vcec(B4)
—~
D451
pin3
>
pin2
DY
~
C461
VR431/R459.
An
electric
charge
is
then
stored
in
C461.
In
the
last
half
of
scanning
the
current
path
is
C461
DY
pin2
pint
~
VR431/R459
C461.
In
this
way,
an
amplifying
sawtooth
waveform
current
flows
directly
to
DY
to
perform
electron
beam
defection.
Next,
in
the
first
half
of
the
banking
period
the
vertical
drive
pulse
suddenly
becomes
OFF,
and
in
order
to
reduce
the
current
flowing
to
DY,
the
current
path
becomes
as
follows
by
the
inductance
of
DY:
DY
pin2
pint
VR431/R459
C461
DY.
Also,
when
the
charge
of
DY
has
dissipated,
the
current
path
becomes
Vcc24V
pin6
pin7
C452
-+
pin3
>
pin2-
DY
C461
VR431/R459,
and
when
the
prescribed
current
value
is
reached,
the
vertical
drive
pulse
becomes
ON.
This
completes
one
cycle.
6.HORIZONTAL
OUTPUT
A
horizontal
oscillation
signal
is
output
from
pin37
of
1C101
and
switches
the
drive
transistor
Q431.
This
switching
signal
is
current
amplified
by
the
drive
transformer
T431
and
drives
the
output
transistor
Q432.
When
Q432
becomes
ON,
an
amplifying
current
flows
directly
to
DY
through
C441/442
-
DY
0432
GND,
-4-
ar

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Sanyo C14EA80D Specifications

General IconGeneral
BrandSanyo
ModelC14EA80D
CategoryTV
LanguageEnglish

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