Philips 107T6, Руководство по обслуживанию

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8639 000 15483
BRAND : PHILIPS
1 inch Monitor 7 CRT
TYPE :
107T60/00
2004-04-19
2004-04-19
4 3
54
107T6 CRT
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BRIEF CIRCUIT DESCRIPTION
!
!
HORI
Z
ONT
A
L DEFLECTION /
V
ERTIC
A
L DEFLECTION / EHT
G
ENER
A
TOR
:
T
he heart of horizontal
/
vertical deflection controller is
D
emic
IC - S
AA
4
8
4
8, which can offer a complete and
efficient small signal sync processing for auto
-
sync monitors. All functions are controlled via
I2C
bus.
T
his controller provides sync processing, which can accept separate and composite (
H
+V) input signals. A
very short settling time after mode change for protection of external power components has been taken into
account.
H
owever, it should be noted that according to V
32 107T6
spec this monitor doesn't support
composite (
H
+V) input signals to avoid some troubles.
T
he
S
AA
4
8
4
8 provides extensive functions like a flexible
B
+ controller block of
H-
deflection and a geometry
control with facility, leading to excellent picture quality.
T
his device also can directly drive the vertical
deflection output stage.
T
he line driver stage, the
E/
W output stage and all controls are tracked with the
incoming frequencies.
P
icture can be adjusted along horizontal
/
vertical direction by
OSD H-
shift
/
V
-
shift
control.
T
he horizontal size, east
/
west, trapezoid corrections can be adjusted by the output of pin
35
(
E
Wout),
which is led to the diode modulation circuit.
S-
capacitors plus power M
OSFET
switches and
DC
controlled
linearity coil are designed for optimal picture linearity.
T
he majority of vertical deflection function is integrated by two
IC
s :
S
AA
4
8
4
8 and
TD
A
4
8
63
.
T
he
S
AA
4
8
4
8 takes care of sync polarity correction, automatic catching and holding of the vertical oscillator,
generation of saw
-
tooth drive current for vertical output and vertical s
-
correction, and generation of a correct
V
-
blanking pulse for video blanking during vertical retrace time.
T
he
TD
A
4
8
63
is a
DC-
coupled vertical deflection booster with differential input signals, suitable for color
monitors.
T
he output stage has thermal and soar protection, and high linear saw
-
tooth signal amplification to
obtain the required vertical deflection current.
T
he voltage supply at flyback time for output stage is generated
by the internal flyback generator and the external diode (
6401
) and capacitor (
2405
) which make the so
-
called
pump
-
up circuit.
EHT
G
ENER
A
TOR
T
he
IC S
AA
4
8
4
8 is also used as a controller to generate required extra high voltage for
CRT
via a buck
converter (
7615
) which supplies the required
B
+ to
LOT
's primary.
T
his is a conventional combination circuit
of horizontal deflection and
EHT
generation.
F
lyback transformer (
LOT
) transfers the primary voltage to the required anode voltage and rest tertiary output
voltages.
T
he adjustable focus (G
3
) and screen (G
2
) voltages are internally derived from the anode voltage.
Another secondary winding is used to generate the voltage for G
1
.
D
ynamic focus on G
4
is derived from a
D
A
F
transformer (
5671
) to get a good focus performance. (G
4
is also adjustable in factory mode).
F
or safety reasons, x
-
ray protection circuit is included, that
S
AA
4
8
4
8 will shut down
EHT
generator and
horizontal deflection if the anode voltage exceeds a certain value (
27-29
kV).
V
IDEO
AM
PLIFIER
&
DDC2B
T
he video circuit mainly consists of
L
ight
F
rame
IC TD
A
4
8
23
, pre
-
amplifier
NT6
8
12
, post amplifier
ST
V
9556
and
DC
restoration
IC L
M
24
8
0
.
T
he video
DC
level and gain at cathode are controlled via
I2C
bus & software.
When
L
ightframe
IC
is enabled by pressing the
LF
key,
R
G
B
input signals will be amplified with an extra
amplification factor up to
1
.
4
.
HORIZONTAL DEFLECTION
VERTICAL DEFLECTION:
VIDEO AMPLIFIER: