Genius 2093 User Manual

2SC3467

390

Ω

, 2W

1N4148

1N4148

4.5-5.3V

5Vpp 16,E5

Vs

16

14

15

GND

370

22K

V. Ref.

GND

408

15.8K

11

12

13

GND

Boost

Vert.

Out

Thermal Protection

1N4005

397

.1uF

395

0

Ω

404

407

372

371

200K

200K

PN2222

373

PN2222

411

 Vertical Linearity Circuit

382

406

405

DECREASES

TOP AND

BOTTOM

VERT. SIZE.

I

MPS2907

413

200K

412

200K

H

INCREASES

TOP AND

BOTTOM

VERT. SIZE.

409

1.5-2.7V

24Vpp 24,E4

Vs

4.7

Ω

396

VERTICAL DEFLECTION SCHEMATIC.

197

2SC4159E

119

1,000uF

+

198

30

Ω

196

270

Ω

199

1N4005

399

.1uF

GND

Capacitor multiplier for the 2793.

196

22-28V

.8Vpp 24,F7

Vs

12-16V

DC

50Vpp 28,F6

Vs

VERTICAL

YOKE

YC1

426

RAS. POS.

0 TO 7 VDC

V

420

100

Ω

 1/2W

394

421

+

1,000uF
   35V

449

V.+12V

LA7851

See

Table

See

Table

YC2

427

81

In similar manner, the positive half of the
vertical current waveform is conducted by
transistor   

373

  diode   

405

  , and resistors   

372

and   

404

  .  Both transistors   

373

  and   

411

  may

be connected to pin 4 via solder connection  H  or
they may be connected to inverting transistor   
  

409

  and resistors   

412

  and   

413

 .   

The inverting transistor is connected with 
solder connection   I  and decreases the vertical
size at the top and bottom of the screen.

     The ramp capacitor   

401

  is connected to a

differential amplifier at pin 6 and the negative
feedback from the yoke return line is connected
to pin 7.   This negative feedback, which senses
the DC component of the vertical output voltage,
is also the current feedback for the LA7838.  It is
made up of voltage divider resistors   

388

  and  

  

390

  +   

393

  and a wave shaping integrator.

The wave shaping integrator, capacitor   

391

  and

resistor   

392

  , is used as the primary vertical

linearity adjustment.

     The output of the vertical drive, differential
amplifier, is connected to the power amplifier
which drives the yoke.   A booster circuit is
connected to the the power amplifier supply via
capacitor  

380

   and clamp diode  

382

   such that

when the booster is active, during vertical
retrace, the power supply to the vertical output
amplifier is doubled.  Resistor   
  

396

  and capacitor   

397

  make up a high

frequency vertical output stabilization circuit.

     The vertical output at pin 12 is connected to
the vertical yoke.  Resistor  

421 

  is a load resistor

across the yoke which stabilizes the vertical
deflection feedback loop.   The yoke return is
decoupled by capacitor   

449

  and the vertical

current is sensed by resistor   

385

  .   The vertical

raster position is adjusted by injecting current in
the vertical yoke return.    This is accomplished
by transistor   

420

  , with emitter resistor   

394

 ,

and the 

V. RAS. POS.

 control   

483

  .

     A capacitive multiplier circuit is connected in
series with the 27 volt line, in the 27” monitor, to
reduce the ripple voltage due to beam current
variations.   Transistor   

197

  conducts current

from the 27 volt line to the LA7838 deflection
supply input pin 8.   Capacitor   

119

  and resistors 

  

196

  and  

198

   form a low pass filter which is

connected to the base of this transistor.   Diode 
  

199

  conducts the inductive current from the

vertical yoke during the first part of retrace.     
A jumper at   

196

  replaces the capacitive

multiplier circuit in the chassis with smaller
CRTs.

405

373

372

388

390

393

401

404

413

409

198

196

199

391

392

394

420

197

119

196

421

396

382

397

385

449

380

412

H

I

483

373

411