BLOCK DIAGRAM - 14 - POWER INPUT 100~240VAC (50/60Hz) Line Filter Degaussing Circuit < OSD Control > SMPS TRANS (T901) SMPS CONTROL (IC901) DPM CONTROL CIRCUIT 190V 23V -12V -12V 125V 80V 15V 12V 6.3V TILT Control Circuit 6.3V 6.3V 12V 5V E 2 PROM (IC402) H / V POSITION H / V SIZE SPCC TRAPIZODE PIN BALANCE PARALLELOGRAM TILT CORNERTRAP DDC ON/OFF CLAMP BEEP RECALL DEGAUSS COLOR CONTROL MOIRE LANGUAGE VIDEO LEVEL OSD POSITION PURITY CONVERGENCE 5V OSD IC (IC301) H-Sync Sig V-Sync Sig I 2 C DATA(SDA) I 2 C CLOCK(SCL) VIDEO PRE-AMP (IC302) Signal Cable R G B VIDEO MAIN AMP (IC303) 12V CUT OFF CONTROL 125V 8V 5V H/V Sync Processor ( IC701 ) TDA4856 V-OUT ( IC601) TDA8172 H-OUT ( Q708) H-Linearity Correction DC/DC Converter X-RAY Protection Circuit FBT ( T701 ) Dynamic Focus Circuit Auto Beam Limit Vertical Blanking, Brightness Control -120V 30V 900V H.V CONTROL DUMMY TRANS 12V 15V MICOM (IC401) SCL / SDA H/V Sync, PWM Control Sig 12V 15V -12V 190V DY CDT Heater ( 6.3V ) I 2 C I 2 C I 2 C I 2 C I 2 C H/V Sync G1 Screen Dynamic Focus Static Focus H.V R/G/B Bias R/G/B Contrast H-DRV B-DRV 15V 15V TILT COIL COIL DEGAUSSING COIL I 2 C VOLTAGE FEEDBACK VOLTAGE FEEDBACK SubTrans Control (IC903) Sub Trans T903 Purity Control Circuit PURITY H- Conver gence BRIGHTNESS CONTRAST
Transcript
BLOCK DIAGRAM
- 14 -
PO
WE
R IN
PU
T10
0~24
0VA
C(5
0/60
Hz)
Line
Filt
er
Deg
auss
ing
Circ
uit
< O
SD
Con
trol
>
SM
PS
TR
AN
S(T
901)
SM
PS
CO
NT
RO
L(I
C90
1)
DP
MC
ON
TR
OL
CIR
CU
IT
190V
23V
-12V
-12V
125V
80V
15V
12V
6.3V
TIL
TC
ontr
olC
ircui
t
6.3V
6.3V
12V
5V
E2 P
RO
M(I
C40
2)
H /
V P
OS
ITIO
NH
/ V
SIZ
ES
PC
CT
RA
PIZ
OD
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IN B
ALA
NC
EP
AR
ALL
ELO
GR
AM
TIL
T
CO
RN
ER
TR
AP
DD
C O
N/O
FF
CLA
MP
BE
EP
RE
CA
LLD
EG
AU
SS
CO
LOR
CO
NT
RO
L
MO
IRE
LAN
GU
AG
E
VID
EO
LE
VE
LO
SD
PO
SIT
ION
PU
RIT
YC
ON
VE
RG
EN
CE
5V
OS
D IC
(IC
301)
H-S
ync
Sig
V-S
ync
Sig
I2C
DA
TA
(SD
A)
I2C
CLO
CK
(SC
L)
VID
EO
PR
E-A
MP
(IC
302)
Sig
nal
Cab
leR G B
VID
EO
MA
IN A
MP
(IC
303)
12V
CU
T O
FF
CO
NT
RO
L
125V 8V
5V H/V
Syn
c P
roce
ssor
( IC
701
)T
DA
4856
V-O
UT
( IC
601)
TD
A81
72
H-O
UT
( Q
708)
H-L
inea
rity
Cor
rect
ion
DC
/DC
Con
vert
er
X-R
AY
Pro
tect
ion
Circ
uit
FB
T(
T70
1 )
Dyn
amic
Foc
usC
ircui
t
Aut
oB
eam
Lim
it
Ver
tical
Bla
nkin
g,B
right
ness
Con
trol
-120
V
30V
900V
H.V
CO
NT
RO
L
DU
MM
YT
RA
NS
12V
15V
MIC
OM
(IC
401)
SC
L / S
DA
H/V
Syn
c,P
WM
Con
trol
Sig
12
V
15V
-12V
190V
DY
CD
T
Hea
ter
( 6.
3V )
I2C
I2C
I2C
I2C
I2C
H/V
Syn
c
G1Screen
Dynamic FocusStatic Focus
H.V
R/G
/B
Bia
sR
/G/B
Con
tras
t H-D
RV
B-D
RV
15V
15V
TILT COIL COIL
DEGAUSSINGCOIL
I2C
VO
LTA
GE
FE
ED
BA
CK
VO
LTA
GE
FE
ED
BA
CK
Sub
Tra
nsC
ontr
ol(I
C90
3)
Sub
Tra
nsT
903
Pur
ityC
ontr
olC
ircui
t
PURITY
H-
Con
ver
genc
e
BR
IGH
TN
ES
SC
ON
TR
AS
T
DESCRIPTION OF BLOCK DIAGRAM
- 15 -
1. Line Filter & Associated Circuit.This is used for suppressing noise of power input lineflowing into the monitor and/or some noise generatedin this monitor flowing out through the power inputline.That is to say, this circuit prevents interferencebetween the monitor and other electric appliances.
2. Degauss Circuit & Coil.The degauss circuit consists of the degaussing coil,the PTC (Positive Temperature Coefficient) thermistor(TH901), and the relay (RL901). This circuit eliminatesabnormal color of the screen automatically bydegaussing the slot mask in the CDT when turn on thepower switch.When you need to degauss while using the monitor,select DEGAUSS on the OSD menu.
3. SMPS (Switching Mode Power Supply).This circuit works with power of 110-240Vac(50/60Hz).
The operation procedure is as follows:
1) AC input voltage is rectified and smoothed by the bridge diode (D901) and the capacitor (C907).
2) The rectified voltage (DC voltage) is applied to the primary coil of the transformer (T901).
3) The control IC (IC901) generates switching pulseto turn on and off the primary coil of thetransformer (T901) repeatedly.
4) Depending on the turn ratio of the transformer, the secondary voltages appear at the secondary coil ofthe transformer (T901). The switch IC(IC903)contrals input-pulse-width and generates secondaryvoltage by sub-transformer (T903).
5) These secondary voltages are rectified by each diode (D906, D907, D908, D909, D910, D911,D912, D913) and operate the other circuits.(Deflection, Video Amplifier, etc.)
4. Display Power Management Circuit.This circuit control power consumption of the monitorby detecting H and V sync signal. There are stand-byand suspend mode. When no horizontal or verticalsync signal input, the circuit consists of Q930 andQ931 becomes stand-by and suspend mode. It’spower consumption is below 8W. When no horizontaland vertical sync signal input, it’s power consumptionis below 3W.
5. X-ray Protection.This circuit detects the rectified DC voltage comesfrom the FBT pin 4. If the high voltage of the FBTreaches up to about 30kV (abnormal state),Micom(IC401) detects. It stops B+ voltage supplied tothe FBT (T701), and high voltage is not be generated,(In the normal state, the high voltage is about 26kV.)
6. Micom(Microprocessor) Circuit.The operating procedure of Micom (Microprocessor)and its associated circuit is as follows:
1) H and V sync signal is supplied from Signal Cable to theMicom (IC401).
2) The Micom (IC401) distinguishes polarity andfrequency of H and V sync.
3) The Micom controls each OSD function signals. (H-size, H-position, V-size, etc.)
4) The controlled data of each mode is stored in IC402.User can adjust screen condition by each OSDfunction. The data of the adjust screen condition isstored automatically.
7. Horizontal and Vertical Synchronous Processor.This circuit generates the horizontal drive pulse andthe vertical drive pulse by taking sync-signal fromSignal Cable. This circuit consists of theTDA4856(IC701) and the associated circuit.
8. D/D (DC to DC) Converter.This circuit supplies DC voltage to the horizontaldeflection output circuit by decreasing DC 190V whichis the secondary voltage of the SMPS in accordancewith the input horizontal sync signal.
9. D/D Drive & Convert Circuit.This circuit is used for supplying B+ voltage tohorizontal deflection output transistor (Q709). Thiscircuit makes to add side-pincushion correcting signalto B+ voltage.
10. Horizontal Deflection Output Circuit.This circuit makes the horizontal deflection bysupplying the saw-tooth current to the horizontaldeflection yoke.
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11. High Voltage Output & FBT (Flyback Transformer).
The high voltage output circuit is used for generatingpulse wave to the primary coil of the FBT (FlybackTransformer (T701)). A boosted voltage (about 26kV)appears at the secondary of the FBT and it is suppliedto the anode of the CDT.And there are another output voltages such as thedynamic focus voltage.
12. H-Linearity Correction Circuit.This circuit corrects the horizontal linearity for eachhorizontal sync frequency.
13. Vertical Output Circuit.This circuit takes the vertical wave from the TDA4856(IC701) and performs the vertical deflection bysupplying the saw-tooth wave current from theTDA8172 (IC601) to the vertical deflection yoke.
14. Dynamic Focus Output Circuit.This circuit takes H and V parabola wave from theTDA4856 (IC701), and amplifies these waves to offerto the FBT (T701).
15. Vertical Blanking and Brightness Control.This circuit eliminates the retrace line by supplying anegative pulse to the G1 of the CDT. The brightnesscontrol circuit is used to control of the screenbrightness by changing the DC level of G1.
16. Image Rotation (Tilt) Circuit.This circuit corrects the tilt of the screen by supplyingthe image rotation signal to the tilt coil which isattached to the CDT near the deflection.
17. Static Convergence Control Circuit.This circuit corrects the convergence of the screen bysupplying the convergence signal to the 4H (STC) coilwhich is attached to the CDT near the deflection.
18. Moiré Reduction CircuitThis circuit reduce interference between the periodicaldisplay pattern and the CDT's slot (or dot).The positions of every other one dot video signalbeams (red, green, and blue beam) are shifted finely,thus reducing interference.
19. OSD Circuit.This circuit is used for performing the OSD (On-Screen- Display) function.When a user selects the OSD Select/Adjustmentcontrol, the adjustment status displays on the screen.
20. Video Pre-Amp Circuit.This circuit amplifies the analog video signal from 0-0.7V to 0-4V. This circuit is operated by taking theclamp, R, G, B drives, and contrast signals from theMicom (IC401).
21. Video Output Amp Circuit.This circuit amplifies the video signal which comesfrom the video pre-amp circuit and amplified videosignal is applied to the CDT cathode.
