Genius 3693 User Manual
RC4
483
482
486
500
Ω
750
Ω
1K
Vertical
Raster
Position
Vertical
Size
RC8
RC6
RC3
Remote Control Board
.1-.3VCD
3.8Vpp 17,E5
3.8Vpp 17,E5
Vs
4-6VDC
2.8Vpp 18,D5
Vs
5.5-6.5V
1.4Vpp 23,F4
Vs
GND
18
17
GND
410
VERT.
OSC.
± SYNC INPUT
VERTICAL
VERTICAL
OSCILLATOR
OSC. O/S
HEAT
SINK
378
362
365K
414
.01uF
361
127K
1
2
3
4
5
6
7
8
9
10
+12V
Ramp
Gen.
Slope
out
Vert.
Drive
Retrace
Booster
Drive
LA7838
Vertical
Deflection
004
510
Ω
375
401
1uF
380
470uF
388
392
391
393
68.1K
390
385
1.2
Ω
, 1W
403
V. osc.
363
203
0
Ω
V
377
CPC1058
.1uF
2.2M
ADJ.
V.+12V
376
100uF
+
5-6VDC
1.4Vpp 22,E5
Vs
V. size
Control
50/60Hz
5.5-6.4V
3Vpp 21,D5
Vs
One Shot
Tr.
R/C
out
374
.01uF
402
44.2K
Reset
Ramp
Reset
Ramp
369
1,000pF
+
+27V
VERTICAL DEFLECTION CIRCUIT DESCRIPTION.
Vs
VERTICAL SYNC
+12V SUPPLY
5.5-6.5V
1.2Vpp 19,D5
Vs
or
20
19
V+
VERTICAL
367
18
Ω
1N4005
382
H.+12V
VERTICAL
See
Table
The vertical sync comes from the
synchronized vertical sync interface
circuit for monitors without interlace.
For monitors with interlace the vertical
sync comes from the sync comparator
via a coupling capacitor and bypasses
the synchronizing circuit. Pin 19 of the
LA7851 is the vertical sync input and will
start the next oscillator cycle on either the
positive or negative sync pulse. The vertical
oscillator capacitor
synchronized vertical sync interface
circuit for monitors without interlace.
For monitors with interlace the vertical
sync comes from the sync comparator
via a coupling capacitor and bypasses
the synchronizing circuit. Pin 19 of the
LA7851 is the vertical sync input and will
start the next oscillator cycle on either the
positive or negative sync pulse. The vertical
oscillator capacitor
410
discharges to 4 volts
on the leading edge of the vertical sync by the
action of an internal transistor and resistor.
Capacitor
action of an internal transistor and resistor.
Capacitor
410
is then charged by resistor
362
until the next sync pulse or to
8 volts, which ever comes first. The V. osc.
frequency is set low such that the adjustment
resistor
frequency is set low such that the adjustment
resistor
363
can be used to act as a vertical
hold adjustment. Solder connection
V
is
used to make this adjustment.
The one shot in the LA7838 clamps the ramp
forming capacitor
forming capacitor
401
to 5 volts for about half of
the vertical retrace time. Capacitor
374
and
resistor
402
form the RC circuit for the ramp
reset one shot.
The ramp capacitor
401
is charged by current
from a current generator with a 6 volt input node
at pin 4. The vertical size is adjusted by the
vertical size control
at pin 4. The vertical size is adjusted by the
vertical size control
482
which is connected to pin
4 via resistors
003
&
375
. The adjustment
range is set by resistor
375
and the maximum
deflection is set by resistor
403
. A third input
to pin 4 comes from the vertical linearity circuit.
This circuit uses the above and below GND parts of
the vertical current waveform separately.
Transistor
This circuit uses the above and below GND parts of
the vertical current waveform separately.
Transistor
411
conducts when the vertical current
waveform is below GND. This transistor’s emitter
is referenced to GND by diode
is referenced to GND by diode
406
and resistor
371
. The emitter is connected to the vertical
current waveform through resistor
407
which is
adjusted for each tube and yoke combination.
80
The vertical oscillator triggers the vertical
oscillator one shot, which outputs a pulse to
trigger the vertical sync input, pin 2, of the
LA7838. This one shot is also used to
synchronize the CRT auto bias IC.
Resistor
oscillator one shot, which outputs a pulse to
trigger the vertical sync input, pin 2, of the
LA7838. This one shot is also used to
synchronize the CRT auto bias IC.
Resistor
361
& capacitor
414
set the
timeout which must be longer than the CRT
auto bias Vs delay and shorter than the
vertical blanking. Resistors
auto bias Vs delay and shorter than the
vertical blanking. Resistors
370
&
408
supply the pullup for this one shot.
362
370
408
414
361
363
403
384
003
402
407
371
411
375
406
410
482
410
401
375
401
V