Genius 3693, ISO XFR-75W, 2093, 1493, 2793, 1793, 1993 Video Amplifier CIRCUIT, FUNCTION, Description

Page 52

VIDEO AMPLIFIER CIRCUIT, FUNCTION, DESCRIPTION.

The video amplifier, is a high speed push pull

 

 

 

 

 

 

 

 

 

 

 

127V

amplifier, which can swing as much as 90 volts.

 

120V

560

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The maximum dynamic output swing is limited to

 

 

 

 

18

 

60 volts. The rest of the output voltage range is

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K17

 

 

140

 

 

 

 

 

 

K14

 

reserved for bias adjustment.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2SA1370

 

 

 

+12V

 

 

 

 

 

12.1K

 

K16

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2N

 

1.49K

 

 

 

 

 

K15

 

 

 

 

.015uF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VIDEO

301

3904

 

 

K9

 

40.2K

 

 

 

 

 

 

885

 

 

 

 

 

 

OUTPUT

K2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INTERFACE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K34

1

 

 

K19

16V

2SC3467

 

 

+

 

 

MPS2907

 

 

 

 

 

 

 

 

 

 

 

 

 

 

606

 

NE592

7

 

 

 

K7

 

 

 

 

 

 

 

15Ω

 

14

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

945

K4

C5346

681

 

 

5.62K

1.50K

 

 

K11

Bias Control Line

+9.25V line

K1

K6

836

 

 

from Auto Bias IC

 

SIMPLIFIED VIDEO

 

K10

 

 

 

 

AMPLIFIER CIRCUIT:

 

 

 

 

 

 

 

 

 

 

 

 

The video amplifier drive circuit is built on a ceramic substrate which is a good heat sink. The printed resistors and conductors are small and have precise geometries which output a faithful reproduction of the input signal with good high frequency response and low overshoot.

The NE592 is a 120MHz emitter coupled differential amplifier which is connected to a push pull output stage. This output stage has a low bias current of 3mA and a bandwidth of 25MHz. Although at 25MHz, the output stage current increases to 15mA.

VIDEO AMPLIFIER CIRCUIT DESCRIPTION

The video amplifier's output voltage, with no input signal, is the black level which is the picture tube cut off voltage. This voltage is set, for each of the three video amplifiers, by the auto bias circuit via the bias control line. This black level voltage has a range of 80V to 110V.

The voltage swing at the output is 60 volts for a 10 mA current signal from the C5346. For this same 10 mA current signal, the voltage swing at the video amplifier input is

1.5volts and the input voltage swing at the NE592 is .80 volts. The reason for using the voltage divider K6 and K7 is that the C5346 minimum output voltage is 7.7 volts, and the bias voltage at the NE592 input is 5.3 volts.

The input signal is buffered by a NPN

transistor

 

K34

for low input capacitance.

Resistors

 

 

 

and

 

set the black level

 

K1

 

K2

input voltage at 10 volts. Resistor K21 (see

schematic next page) and diode K36 protect the input against arc related transients. Resistors K6 and K7 are used to set the input bias voltage for the NE592. Diode K35 acts as a temperature compensator to match the emitter to base diode in the

buffer transistor.

The negative feedback circuit consists of

bias resistors

K9

,

K10

and output feedback

resistor

 

.

The geometry of the feedback

K19

circuit defines the AC negative feedback path. The autobias output, which adjusts the black level voltage, is also connected to this node

through resistor K11 . Solder connection A connects resistor K22 , which raises the video amp. output voltage by 10V, for some CRTs.

The voltage gain of the differential amplifier K32 is set by resistor K8 . The

output of the amplifier has a load resistor K5 for faster low going transitions and is

buffered by a PNP transistor 945 with base

matching resistor K20 . The load resistor for

this buffer amplifier is K3 which is connected to the 16 volt line.

The buffered output of the differential amplifier is DC coupled to the NPN transistor

 

943

and AC coupled, by capacitor

 

885

, to

 

the

PNP transistor

 

of the push-pull

951

output stage. Resistors

 

 

and

 

 

 

 

 

K18

953

 

 

protect the push-pull transistors from current spikes caused by voltage transients when CRT arcing occurs.

68

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Contents N U a L R V I C E Year Limited Warranty About this Manual Table of Contents Iii Monitor Simplified Block Diagram Installation Instructions For The XX93 Monitors Instructions d´installation des écrans Installationsanweisungen für die XX93 Monitore Ceronix XX93 Monitor Electrical Specification High input voltage 20V Low input voltage 30V 80V Ceronix 189 in2 1,224 cm2 Page Page Page Page Control Description Circuit XX93 Monitor Block Diagram CRT C D E F G H I J Ceronix Model 1493-VGA, 1493-SVGA CPT1536 Ceronix KLM RED FIL RAY Note Produktsicherheit Anmerkung Ceronix XX93 Monitor Part List MM7 LL6 II7 FF9 FF3 BB6 DD8 DD9 HH2 Jumper, Normal Vertical OO6 15KHz, FBT Hitachi BW02651 PP4 RR0 VV2 RR7 CRT T U Video Interface CIRCUIT, FUNCTION, Description + & Analog CRT TC12 Controls XRC5346A + H. Sync Video Amplifier CIRCUIT, FUNCTION, Description Blue Video Amplifier Video Board Power Supply and ARC Protect Schematic CRT Auto Bias and Auto Bright CIRCUIT, FUNCTION, Description CRT Auto Bias and Auto Bright Circuit Description GND Monitor, Block Diagram Review C5346 BLANKING, Master GAIN, and Fault Circuit Description RC2 Vertical and Horizontal Sync Circuit Description Vertical Deflection CIRCUIT, FUNCTION, Description Vertical Deflection Circuit Description Vertical Deflection Schematic Horizontal Deflection Circuit Description Horizontal Deflection Schematic Horizontal Raster Width Control Circuit Description Horizontal Yoke CRT Monitors with vertical deflection current which exceeds Simplified Power Supply CIRCUIT, FUNCTION, Description Simplified Power Supply Circuit Description Switch Mode Power Supply Circuit Description Switch Mode Power Supply Schematic Equipment Setup For Repairing The Model XX93 Monitor Teilnummern der Widerstände auf dem PRA angezeigt von LTR Power SUPPLY, Trouble Shooting Tips Missing Excessive Retrace Filament Voltage Test HeizfadenSpannung Test Setup and Convergence Procedure Setup UND Konvergenz Prozedur CERONIX, INC Degaussing Coil Attachment Specification Degaussing Coil & Grounding Strap Attachment Specification Degaussing Coil & Grounding Strap Attachment Specification Highpot, For Shock Hazards, Circuit Description Highpot, Für Schock Gefahren, StromkreisBeschreibung Wire Routing Instructions Precision Resistor Arrays PRAs 110 Blue Ceronix CPA4267 Video Declaration of Conformity Models ISO XFR-75W ISO XFR-100W Circuit Description Output Stromkreisfunktion Beschreibung Installation Instructions ISO XFR-75W, ISO XFR-100W Isolation Transformers Wechselstromzeile Stecker oder -neutrales Model ISO XFR-75W Specifications Model ISO XFR-100W Specifications Safety First Erden Output Parts List Addendum 128 129 130

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.