7-1
SECTION VII HORIZONTAL AND VERTICAL OSCILLATION CIRCUIT
Ordinary TV uses the osc circuit contained inside V/C/D IC, but this model can not use this due to Multi Scan TV covering 15kHz
to 40kHz. Other IC ICH08 (LA7860) for oscillation is added. This IC is for CRT monitor, and the hor osc frequency, the hor
phase and the duty ratio of hor output pulse can be controlled by d.c. voltage. Block diagram is shown below.
0.1µ
330k
0.015µ
V.SYNC
1µ
12V
18k
Vvs
5k
VRS
V.BLK
V.D
0.01µ
3300p
100µ
0.01µ
160p
22k
30k
H.LOCK
FBP
H.D
161718192021222324252627282930
V.Ref
V.OSC
RAMP.G
V.OUT
H.LOCK
SAW
M.M
H.OUT
COMP
H.OSC
AFC
V/I
2nd delay
1st delay
123456789101112131415
To
14pin
To
14pin
To
14pin
To
14pin
To
14pin
EN
0.01µ
H.SYNC
22k
0.01µ
0.01µ
0.01µ
4.7µ
1200p
12k
VR2
5k
VR3
5k
560p
VR1
5k
12k
Vosc
1.8k
100
1µ
2
1
0.001µ
3.3k
2.2µ
2.2µ
1200p
SW2
0.01µ
1000µ
470p
60mA
0.01µ
VR4
Vdet
5k
12k
H.REG
9V
NC12V
V.BLK
V.D
Vh
12k
Vhg
Fig. 1 Circuit for measuring electrical characteristics
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