3-14. DEFLECTION CIRCUIT (DA BOARD)
3-14-1. H Delay and Horizontal AFC (Automatic Frequency
Control) Circuit
In this model H delay function is performed by delaying H. AFC
pulse in the horizontal AFC circuit. (See Figure 31)
H. AFC pulse which is fed from H.O.T. (Horizontal Output trans-
former) is wave shaped and is delayed about 20 µs by !CI 12/2).
This delayed pulse is integrated by inductor LI. and capacitor Cl 4.
thus sawtooth waveform is obtained and fed to terminal pin 0
of IC4. AFC detection is performed by IC4. Output of AFC detector
is fed to control terminal of horizontal oscillator (H.OSC) via low
pass filter composed of capacitor CI 2, CI 5 and resistor R 10.
3 types of AFC mode are selected by changing low pass filter which
determines AfC time constant.
AFC time comtant circuit is composed of switch Sl. resistor RI 3,
Rl4. RlS and capacitor Cl 7, Cl 8.
:.-- IH _ __.J
1
20JJsec
1
14-_..,
~
I '
AFC PULSE
DELAYED AFC PULSE l
-+u----+u
I '
I
I
:~
u
H SYNC
J
When H DELAY
1s applied
Pulse at H delay operation
Figure 31
3-14-2. Horizontal Linearity Correction Circuit
In this model Horizontal Linearity correction is made by applying
correction voltage to the Horizontal def1ection circuit.
Basically, Linearity correction is made by modulating power source
of horizontal output circuit with horizontal sawtooth voltage.
Also So-called "Inside pincushion" correction is performed by
applying correction waveform to S correction capacitor.
This correction waveform is generated by balanced modulator
(IC7) with vertical rate parabola waveform. See Figure 32.
Horizontal sawtooth waveform is generated by JCS (1/2) for
horizontal linearity correction. Horizontal rate parabola waveform
is f!Cnerated by integration of saw tooth by IC6 ( I /2). This parabola
waveform is performed balanced modulation by IC7 with vertical
rate parabola waveform, horizontal sawtooh and parabola wave-
form are fed to horizontal linearity output amplifier in EA board.
Correction of horizontal linearity correction and inside pincushion
correction are performed.
•C1 \~) P11,j
l
\+>--- -- -----1-1 ~•N
4 CORRECTION
WAVE FORM
~~n~
Voltage of S correction capacitor
r\f\0
r -
~
®.
- " - Horizontal linearity correction waveform
Figure 32
3-31
3-14-3. Horizontal Blanking Pulse Generator
Horizontal rate sawtooth waveform generated in H. Linearity
circuit is fed to the comparator IC8 (1/2). In this circuit, 1/2H de-
layed pulse is obtained. This pulse is fed to integrator IC9 (1/2) and
l/2H delayed sawtooth waveform is obtained and this is fed to the
comparator ICI0 (1/2).
Thus the comparator generates horizontal pulse to make H. Blank-
ing pulse wich starts just before the starting edge of the retrace
time. Also width of horizontal blanking pulse is determined by
JK-FF IC! (1/2).
:.--1 H-+j
I
~
COMPARATOR
0
--+---V~1
:~IH~
.1L___L
~
~
'
'
IC 101 I /21
AFC
IC 1012121 OUT
Tl B H, F+iASE
+12
~
06 COLLECTOR
-12
Figure 33
3-14-4. Top & Bottom Pincushion Circuit
Horizontal rate sawtooth waveform generated in H Linearity cirl'Uit
is also fed to !Cl 0. !Cl 0 generates advanced H pulse for the phase
correction because vertical Deflection Yoke works as an integrator
at horizontal rate, and deflection current for Top & Bottom pin-
cushion correction is delayed about l/2H for this reason. See Figure
33.
Advanced H pulse is fed to IC! I 11/2) and advanced honzontal
sawtooth waveform is generated. It is integrated by IC I l I 2/2)
and horizontal rate parabola waveform is obtained.
Modulated butterfly waveform for Top & Bottom pincushion
correction is obtained by Balanced modulator !Cl 2. In this balanced
modulator, horizontal rate parabola waveform is used as a carrier
and vertical rate sawtooth waveform is modulated by this carrier.
See Figure 34.
This correction waveform is fed to vertical deflection output
amplifier in FB board.
carrier \[¥\.
I.-.,;
IH
0~
I
-iv~
OUT
~
+ V cc
L ,v-J
ICI2
BALANCED MODULATOR
Figure 34
3-14-5. Autmatic 50/60Hz Field Selection Circuit
This model has an automatic vertical field frequency selection
circuit so that color systems with different frequencies such as
NTSC or PAL and SEC AM can be received. IC'I8 is automatic field
frequency detection device and its output switches (IC13) time con-
stant of integrator in vertical deflection circuit.
3-14-6. Scan Mode Selection Circuit
There are 3 modes of scanning in this model: NORMAL SCAN/
UNDERSCAN~ETUPSCAN
There are level adjustments for Hl width, V, height side pincushion
and top & bottom pincushion .
Levels of correction waveforms are switched so that these adjust-
ments are made independently for each scanning mode. IC14, ICIS
and ICl6 activates for this purpose.
3-14-7. Vertical Deflection, Side Pincushion Correction
IC l 9 ( I /2) generates vertical rate sawtooth waveform for vertical
deflection. V sawtooth waveform is generated by the integrator
IC9 ( 1/2) which is reset by V sync.
Also vertical rate parabola is generated by integrating V. sawtooth
waveform by IC9 (2/2).
This V parabola is used for side pincushion correction, and also
V. parabola is converted to sine waveform by IC20 (1/2) and is
mi,ed with V parabola waveform. This mixed waveform is used for
side pincushion correction and fed to side pincushion output
amplifier in EA board.
Vertical drive voltage for vertical deflection is generated by mixing
vertical rate sawtooth waveform generated by !Cl 9 (1/2) and sine
waveform generated by IC22 (i/2).
This drive waveform is fed to vertical def1ection output amplifier.
Balance adjustment of vertical linearity correction can be performed
by IC22 ( I /2) and vertical centering can be adjusted by IC22 12/2).
l.-1v-+1
f4---I v--------j
i---I V----j
1
,-b4
'
'(\'
:/\ :1
\ I I /
\JV
I
V
f ( X) = X
f(x)=1-x
2
f(x)=x-x
3
-Vee
-Vee
J
J
J
IC 191 I /21
ICl912/21 IC2011/21
-Vee
V .LIN.
J
1(2012/21 IC2111/21
V .LIN. GAIN
I
BALANCE
!C221I/21
-Vee
v,
Vo
_j_
_j_
INTEGRATOR
Figure 35
3-3°2
SIDE PIN
CORRECTION
WAVE
f--1v---j
0 P'~
J
VERTICAL
SAWTOOTH
V. CENT
+Vee
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