Size Circuit - NEC MultiSync 3D JC-1404HME Service Manual

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(2-5-7) V. Size Circuit
IC152
µPD6336C IC154
A410
22K
A411
300
C409 A412
0.01µ
I
10K
IC511
A415 A416 A419
150K 560K 53'JK
V. SIZE
V-F/V R417
100K
A419
100K
C411
11,136V
TANT AL
D404
TVA-0.6G
A423
8.2K
R421
22K
R422
C416
22K
4.7~
16V
Tantal
(Fig. 2-5-14) BLOCK DIAGRAM of V. SIZE CIRCUIT
C413
220P
A428
R425
270
18K
+
C418
1000µ
- 50V
R426
1.5
2W
The vertical raster size is controlled by the sink current of IC402 pin 3 (collecter current of 0402).
Therefore, it can be controlled by changing the DC base voltage of 0402. The parameters which
decide the vertical video size are the vertical frequency and the signal timing.
To keep a constant vertical raster size, the V. F/V (IC154 pin 8) output signal controls the 0402
base voltage. And, to also keep th is vertical raster size constant for the pre-set signals, the V. size
control voltage (IC154 pin 14) controls the base voltage of 0402.
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