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H. POSI
H. SIZE
SIGNAL CABLE
V. POSI
V. SIZE 5V
DATA IN PUT 5V 12V 12V 70V
S.PCC
H.S (H/V)
DY
V.S
TRAP R R
SYNC PROCESSOR G VIDEO DRIVE G
MICOM VIDEO OUTPUT CDT
& PORT CONTROL B CONTRAST B
SELECT
UP
SCREEN
RECALL
DOWN
D. FOCUS
S. FOCUS
SCREEN
V.DY
6.3V
H.DY
CONTROL BUS
G1
M.DEGAUSSING PWM
EEPROM CRT CUT-OFF
7 PORTS 170V H.V
ADJUSTMENT
70V
12V
BLOCK DIAGRAM
5V
BRIGHTNESS
12V -9V
H/V BLANKING
CONTRAST
VERT. OUT & BRIGHTNESS
H.SIZE & S.PCC
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POWER TDA8172 CONTROL
MANUAL & TRAP
LED 15V
DEGAUSSING
RECTIFIER
-100V
30V
170V
26KV
170V 12V
3122
70V HORZ.
SMPS S-CORRECTION
OVER CURRENT TRANS
D/D CONVERTER
LINE PROTECTION
5V 60~145V
FILTER 35V F.B.T
GL7805
&
6.3V 170V
SMPS RECTIFIER 12V
-9V 15V
CONTROL
STR6707 ABL
HORZ OUT
H/V PROCESSOR
TDA9102C HORZ DRIVE
H.D.T
D.P.M (POWER OFF SIGNAL)
RECULATION & D.P.M(STAND BY & SUSPEND)
POERT INPUT 170V
D.P.M CONTROL 70V HOR, DRIVE X-RAY D-FOCUS
35V DETECTOR PROTECTION AMP
DESCRIPTION OF BLOCK DIAGRAM
1. SMPS
When you push on the power switch, the operating procedure is as follows;
1) The AC line voltage is rectified by the bridge diode(D901).
2) The control IC(IC901) of SMPS start switcing and generate switching pulses in primary turns of SMPS
treansformer(T901).
3) The switching pulses of primary turns are induced secondary turns of transformer by turn ratio. This pulses are
rectified by each diodes(D913, 932, 941, 951, 952, 964).
4) Each rectified DC voltages(-9V, 6.3V, 15V, 35V, 70V, 170V) is supplies to Main circuit.
2. Over voltage protection
When 170V line voltage is higher than designed value at abnormal state, the control IC(IC901) is shut down.
3. Display power management
1) STAND BY and SUSPEND mode:
When H-sync or V-sync is not input, the circuit which consist of Q904, Q905, Q906, Q907, Q909, Q912, IC901 is operating.
2) OFF mode:
When H-sync and V-sync is not input, the circuit which consist of Q904, Q905, Q906, Q907, Q909, IC901 is operating.
Then the input power consumption is below 8 Watt.
4. X-ray Proctection
This chassis has high voltage detector in fly back transformer(T702). When high voltage is reached to 30kV in
abnormal state, high voltage detector circuit which consist of IC402, Q703, Q704 and Q705 starts operation
and then high voltage shut down.
5. Micro-processor control
The operating procedure is as follows;
1) Sync signals are supplied to the sync processor IC(IC804).
2) Micro-processor(IC802) desciminates operating mode from sync polarity and resolution.
3) After Micro-processor reads this adjusted mode data which are stored at EEPROM(IC803), it controls operating
mode data through pulse width modulation ports.
4) Users can control screen conditions by using select, up and down keys.
6. D/D converter
To obtain constant high voltage, this circuit supplies controlled DC voltage for fly back transformer and horizontal
deflection circuit according to the horizontal sync frequency.
7. H/V processor
H/V Processor IC(IC701) has sync dectetor, saw-tooth generator and drive functions.
8. Horizontal S-correction
This circuit compensates horizontal linearity proportionally according to horizontal frequency.
9. Horizontal drive and output
This circuit is horizontal deflection amplifier for raster scan.
10. ABL
This circuit limits beam current for reliability of cathode ray tube.
11. Vertical output
This circuit is saw-tooth amplifier of vertical deflection for raster scan.
12. H/V blanking & brightness control
Blanking circuit cut off the beam current during the period of horizontal and vertical retrace.
Brightness circuit controls DC voltage level of cathode ray tube's grid 1.
13. D-Focus
This circuit control sine wave voltage for corner focus.
14. Video Processor
Video processor consists of video drive, video output and beam cut off blocks. Video drive IC(IC301) receives
the video signal from personal computer. The gain of each channel is controlled by the voltage of contrast pin.
Cut off circuit compensates the differance voltage of cathode to grid 1.
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