Date: 10/02/98 R762720
R-G-B Driver
R762720
16
Technical description
-
SCAN FAIL
(pin 6):
This line is high when there is no scan fail and drops to zero when scan fail has
been detected.
(note : The scan fail condition also drops the SPOT_KILL line to an active low
level and hence switches off the video output stages of the UN DRIVE board.
- Supply voltages controls (pin 3,4) :
The +/- 12V and +/-5V supply voltages are checked with the window detector
IC105. If one voltage fails or is not within the desired window, the output switches
low and the same pins 3, 4 are pulled low level. Note that this will mean a scan
fail condition and the SPOT_KILL line will be active as well.
-
LEFT/RIGHT
blanking :
The blanking pulses for the beginning of the scan (left blanking) are generated by
IC108 (output 4) by triggering the monoflop on the positive transition of the
LP
pulses. The output pulse train of pin 13 is integrated with R138/C108 and com-
pared with the
LEFT_BLANKING
voltage. The output of the Miller integrator
drives the current source Q104 which determines the pulse width of the blanking
pulses.
The pulses for the end of the scan are generated by the other monoflop in IC108.
Here, the monoflop is triggered by the negative transition and the positive pulses
at pin 5 output are used. Consequently, the low level of these pulses is the
blanking time. It is obvious that, in this case, the negative pulses at pin 12 are
integrated and the obtained voltage is used to adapt the pulse width in conjunc-
tion with the
RIGHT_BLANKING
voltage.
The integration of the pulses (average voltage) means a tracking of the range
with the line frequency. The absolute value of the required blanking is much
smaller for the higher scanning than for the lower scanning signals.
Another tracking is also got by a correction current via D122 and D124 by switching
on Q111 with
HFB
pulses.
I²C Interfacing.
IC100
: the
MIDLIGHTS_RED
and
_BLUE
switching on/off voltages.
IC101
: 3 outputs are the
PEAKING
adjustments.
If no peaking is needed, the three outputs are at approx. -11V and hence Q112 and
Q113 are both conducting. The output
NO_PEAKING
is then at about +12V.
As soon one output of a comparator switches to a positive high, due to the resistive
dividers R171/R172/R173, the emitter of Q112 jumps at -3.5V and the latter gets blocked.
The
NO_PEAKING
line is then at about -5V and D123 is forward biased to keep the
impedance of the
NO_PEAKING
line low and avoid distortions in the RGB DRIVE
stages.
IC100 uses the same address of IC601 on the INPUT board. The data line
SDA
of
either one of these I²C interfaces can be disconnected via a switching Mosfet. To
select this IC100, output port P7 of IC101 must be low level, blocking Q103 and via
R113, Q102 is forward biased.
IC109
:
two outputs are used for the Left/Right blankings and VO3 is the Blue breakpoint
output. The DC range is corrected with IC102 (8, 9, 10).
Summary of Contents for GRAPHICS 1209S
Page 4: ...BARCO PROJECTION SYSTEMS GRAPHICS 1209S 90 00972 230V AC 90 00977 120V AC SAFETY NOTICE...
Page 9: ...BARCO PROJECTION SYSTEMS GRAPHICS 1209S 90 00972 230V AC 90 00977 120V AC GENERAL INFORMATION...
Page 28: ...BARCO PROJECTION SYSTEMS GRAPHICS 1209S 90 00972 230V AC 90 00977 120V AC SERVICE SHEETS...
Page 31: ......
Page 32: ......
Page 41: ......
Page 42: ......
Page 43: ......
Page 44: ......
Page 45: ......
Page 46: ......
Page 47: ......
Page 48: ......
Page 49: ......
Page 50: ......
Page 51: ......
Page 52: ......
Page 71: ......
Page 72: ......
Page 73: ......
Page 74: ......
Page 75: ......
Page 89: ......
Page 90: ......
Page 91: ......
Page 98: ...Date 10 02 98 R762720 R G B Driver R762720 1 SERVICE SHEET...
Page 99: ......
Page 100: ......
Page 101: ......
Page 102: ......
Page 103: ......
Page 104: ......
Page 105: ......
Page 120: ......
Page 121: ......
Page 122: ......
Page 123: ......
Page 124: ......
Page 125: ...Date 10 02 98 R762839 RGB Output ABL CRT R762839 1 SERVICE SHEET...
Page 126: ......
Page 127: ......
Page 128: ......
Page 129: ......
Page 142: ...Date 10 02 98 R7625115 Controller module R7625115 1 SERVICE SHEET R7625115 r00...
Page 143: ......
Page 144: ......
Page 145: ......
Page 146: ......
Page 147: ......
Page 148: ......
Page 149: ......
Page 157: ...Date 10 02 98 762457 Deflection Switching Module 762457 1 SERVICE SHEET...
Page 158: ......
Page 159: ......
Page 166: ...Date 10 02 98 R7621127 Sync Vertical Deflection R7621127 1 SERVICE SHEET...
Page 167: ......
Page 168: ......
Page 169: ......
Page 170: ......
Page 171: ......
Page 172: ......
Page 173: ......
Page 194: ......
Page 195: ......
Page 198: ......
Page 199: ......
Page 200: ......
Page 203: ...Horizontal Deflection 1 Date 10 02 98 R7621085 R7621085 SERVICE SHEET R7621085S...
Page 204: ......
Page 205: ......
Page 206: ......
Page 207: ......
Page 208: ......
Page 222: ......
Page 223: ......
Page 224: ......
Page 225: ......
Page 226: ......
Page 227: ......
Page 241: ......
Page 242: ......
Page 243: ......
Page 244: ......
Page 245: ......
Page 246: ......
Page 247: ......
Page 248: ......
Page 249: ......
Page 267: ......
Page 268: ......
Page 271: ......
Page 272: ......
Page 273: ......
Page 282: ......
Page 283: ......
Page 284: ......
Page 292: ......
Page 293: ......
Page 294: ......
Page 295: ......
Page 307: ...Date 18 06 96 R762284 Power mains input module R762284 1 SERVICE SHEET Rev 01...
Page 308: ......
Page 309: ......
Page 314: ......
Page 315: ......
Page 316: ......
Page 328: ......
Page 329: ......
Page 339: ...Date 10 02 98 R7627591 Frame cpl R7627591 1 SERVICE SHEET R806430...
Page 340: ......
Page 341: ......
Page 354: ...Date 10 02 98 R761781 IR Receiver module R761781 1 SERVICE SHEET IRRECEPTION IRRECEPTION...
Page 355: ......
Page 359: ...Date 10 02 98 R762510 IR RS 232 Communication module 1 R762510 SERVICE SHEET...
Page 360: ......
Page 361: ......
Page 362: ......
Page 366: ......
Page 374: ......
Page 375: ......