Vertical Deflection Circuit - NEC MultiSync 3D JC-1404HME Service Manual

(b) Horizontal output circuit
This circuit produces a sawtooth current waveform to the Horizontal DY by switching 0523
and D522 ON and OFF. In order to meet wide a range of frequencies (15~38 kHz), several
circuit and changed in corresponding frequency bands.
• Horizontal resonant capacitor ..... 17 kHz
• S-correction capacitor ( fH
~
20 kHz
20<fH~27 kHz
27 < fH
~
33 kHz
33 < fH
~
38 kHz
• Drive circuit of 0523 ..... 28 kHz
Due to this switching circuit and multiple DC outputs from the DC to DC converter circuit,
the MS 3D can practically the same size raster and linearity for a wide range of frequencies.
(2-2-2) Vertical deflection circuit
v.osc.
IC401
HA11423
+12V
V.TRIGGER
V-F/V OUT
V-SIZE OUT
V.SIZE
CONTROL
_v_-_Po_s_._o_u_T __
V. POSITION
CONTROL
+24V
V.OUTPUT
IC402 (LA7835)
~ V . D Y
+
C418
V. LINEAR,__ _ _ _ _ - 1000µ 50V
R426
1.5
2W
(Fig. 2-2-2) BLOCK DIAGRAM of vertical deflection
The vertical deflection circuit produces a sawtooth current waveform to the vertical D.Y. The
output of IC402 (LA7835) is suited for multi-scanning monitors because it easily controls the
vertical size (by DC control) and is also easy to synchronize.
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