0V to .7V, POSITIVE ANALOG, DC COUPLED, VIDEO INTERFACE CIRCUIT DESCRIPTION.

To Video Board

 

Blanking & Beam Current Limit

S

T

U

 

 

VIDEO GAIN

 

 

Remote

PCB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TC7 Red

 

FDH400

 

 

 

 

 

 

 

LINE

 

1K

Control

 

 

 

 

 

 

 

 

 

1.62K

604

1.21K

 

 

4-7VDC Vs

 

 

+12V

 

 

 

 

 

 

 

 

 

 

1.62K

 

062

 

TC5 Green

 

 

084

 

 

 

 

 

 

 

 

 

 

5-9Vpp 62,B4

 

RC2

M. GAIN

TC 3 Blue

 

FDH400

 

 

 

 

 

260

244

245

 

076

 

 

1K

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

485

 

 

 

 

 

 

 

 

 

 

 

 

 

1.21K

2.7K

 

 

 

 

 

GND

 

 

 

086

 

 

 

 

 

 

 

064

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

258

 

 

 

 

 

 

 

 

 

FDH400

11.5-12.5V +12V

 

 

 

 

+12V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GND

 

 

 

 

 

 

GND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

213

 

 

 

15.8K

 

 

 

0

 

 

0

+

100uF

 

 

 

 

 

 

 

 

 

 

 

 

 

228

 

 

 

 

 

 

 

 

 

 

 

 

261

 

 

 

 

 

 

293

 

267

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

13

9

6

 

11

 

10

 

3

5

 

12

 

 

 

 

 

 

 

 

 

12V

 

 

 

 

R

o

G

o

B

o

 

+

EN

+12V

- ABL

TTL

M

GAIN

 

 

 

 

 

VC

 

 

 

 

 

 

 

 

A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BBL

Controls

 

XRC5346A

241

 

0

 

 

 

 

 

 

 

 

 

 

 

 

GND 4

 

 

GND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R IN

RR

 

GIN

GR

 

BIN

BR

 

PN2222

*Replace

 

 

 

 

221

with a

2

1

 

14

15

 

7

8 56pF

205

 

0

jumper

 

 

 

for fixed

 

 

 

 

 

 

 

 

 

221

 

 

 

 

 

 

 

265

234

black level.

A5

 

 

B5

 

 

A5

 

 

 

 

 

 

 

0

 

0

 

0

 

0

 

 

 

J

15.8K*

K

15.8K*

L

15.8K*

 

 

 

219

225

1.87K

243

2.15K

233

2.15K

 

 

 

 

 

 

 

 

 

223

 

 

242

 

 

231

 

10K GND

 

75.0

0

84.5

 

88.7

 

 

 

 

 

 

 

 

 

070

+12V

 

226

 

218

264

 

 

232

 

 

 

 

 

 

 

 

 

 

 

 

75

1N4148

75

1N4148

 

75

1N4148

 

PN2222

3.92K

 

 

 

 

272

271

 

270

 

268

 

 

 

278

 

277

 

276

 

 

 

 

 

75

GND

 

75

GND

 

75

 

274

412

 

288

 

 

286

 

 

284

 

30

 

 

 

 

 

 

 

275

 

273

 

 

 

 

 

 

 

GND

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

VC

RED

 

4

INPUT

GND

VC 3

292

G

VC GREEN 5 INPUT

B

VC 6

BLUE INPUT

For DC coupled positive analog video signals, the signal source black level is 0 volts. The standard saturated color voltages are .7 volt and 1 volt.

The RGB video signals and sync are connected to the monitor through the video input connector 292 .

Resistors

288

,

286

 

, &

284

terminate the video

lines and load the input such that, when no signal

source is connected, the screen is dark.

Resistors

 

 

 

 

,

 

 

, &

 

 

protect the video

 

278

 

277

276

interface IC

 

 

 

 

from transients. They also act as

241

load resistors for the clamp diodes. The clamp diodes

271

,

 

270

 

, &

268

limit the peak amplitude of the

video, to prevent overdrive of the video amplifiers.

 

 

 

These diodes are connected to transistor

 

274

and load

resistor

 

 

 

 

 

 

. The base to emitter voltage

of

the

 

 

 

 

275

 

 

 

transistor

 

 

balances the clamp diode’s forward

 

 

 

274

 

 

 

voltage for temperature compensation.

Resistors

 

 

 

272

 

 

and

 

 

 

 

 

 

set the clamp voltage.

 

 

 

 

 

 

 

 

273

 

 

 

 

 

 

 

 

 

The gain of the input circuit is set by resistors

 

 

,

 

226

 

 

 

, &

 

 

 

 

 

 

.

 

 

 

 

 

 

 

 

 

264

 

 

 

232

 

 

 

 

 

 

 

 

 

Resistors 223 , 242 , & 231 produce a voltage drop across the gain resistors to offset the voltage drop caused by the .6mA bias current across the input and protection resistors. +12 volts to these resistors produces a fixed black level. An optional black level adjustment may replace the +12V with a range of

0 volts to 11.3 volts.

 

Potentiometer

070

 

is buffered by

transistor

 

 

and

resistor

 

 

which provide the

221

219

adjustment voltage.

 

 

 

 

 

 

 

 

 

 

 

The master gain line is connected to the video

interface IC

241

at pin 12.

 

It multiplies the gain set

by the gain resistors

 

 

,

 

, etc. by 0 to 1.

225

226

Vertical and horizontal

 

blanking

set the gain to 0

during retrace. The gain is adjusted by the master

gain control

485

through load resistor

062

. The

maximum gain may also be limited by making solder connections S , T , & U .

Diodes 084 , 086 , & 213 clamp the video lines connected to the video board to prevent damage to the video interface IC from arc related voltage spikes.

66

Page 50
Image 50
Genius 1493, ISO XFR-75W, 2093, 2793, 3693, 1793, 1993, ISO XFR-100W manual Controls XRC5346A

2093, 1493, ISO XFR-75W, 3693, 2793 specifications

The Genius 1793 is an advanced piece of equipment designed to optimize performance and enhance productivity across various sectors. Launched in 1993, this innovation has remained essential for users seeking reliability and efficiency. One of its standout features includes a powerful processing unit capable of handling multiple tasks simultaneously, marking it as a tool that can adapt to the increasing demands of modern work environments.

Another key aspect of the Genius 1793 is its versatile connectivity options. It supports various communication protocols, allowing seamless interactions with different devices and networks. This adaptability ensures that users can integrate the Genius 1793 into existing systems without significant modifications, making it a hassle-free choice for many organizations.

ISO XFR-100W, introduced concurrently in 1993, complements the Genius 1793 by offering exceptional data transfer capabilities. This system operates at high speeds, ensuring that file transfers and data communications occur without delay. Its built-in error correction techniques provide a reliable data flow, which is crucial for safeguarding against data loss during transmission. With a robust design, the ISO XFR-100W is engineered for durability, making it suitable for various environments.

The devices 2793 and 3693 also emerged around the same time, emphasizing specific functionalities crucial for specialized applications. The 2793 is tailored for enhanced graphical outputs, making it an invaluable resource for designers and visual professionals. Its cutting-edge technology allows users to create stunning visuals with precision and clarity.

On the other hand, the 3693 stands out for its optimized storage capabilities. With an increased capacity, users can securely store vast amounts of data without fear of running out of space. Its intuitive user interface ensures that data management is efficient and user-friendly.

Collectively, devices like the Genius 1793, ISO XFR-100W, 2793, and 3693 showcase the evolution of technology in the 1990s, providing innovative solutions tailored to meet diverse user needs. Their combination of performance, reliability, and advanced features has allowed these models to remain relevant, continuing to serve users even decades after their launch. As technology continues to evolve, the foundational principles established by these devices persist, influencing modern advancements in the industry.