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attenuation by ATT circuit, they are output to the sound amplification circuit N701 via the
input terminal Pin (6). The sound power amplification is carried out by TA8213K. Finally, the
signals are output to loudspeaker SP901 and SP902.
(5)
Horizontal scanning signal processing
Switch on the set and 9V voltage is sent to N201. The horizontal start voltage is provided by
the internal regulated voltage circuit to make VCO generate 32-fold horizontal frequency
oscillation. With 1/32 frequency distributor and AFC1 and AFC2 phase-shifting circuit, the
horizontal drive pulse generated is output via Pin (32) to drive horizontal driver V431 to
make it work in switch status. The switch pulse is coupled by the horizontal drive transformer
T401 and make the horizontal output tube V432work in switch status. The output signals are
sent to the horizontal deflection coil via S correction capacitance C412 and horizontal
linearity adjustment L414. One linearly varying magnetic field is generated to make the
electron beam of the picture tube move horizontally until the horizontal scanning completes.
About 22KV anode high voltage, 8KV focusing voltage and 6.3 Vrms filament voltage is
generated via horizontal output transformer T402 by making use of the pulse high voltage
generated on the collector electrode of the horizontal output tube V411 during the horizontal
scanning return period. Apart from this, one part of the return pulse voltage output from Pin 5
of T402 is sent to Pin 26 of CPU after phase reverse to be used as synchronizing signal; and
the other part is sent to Pin 30 of N201 via phase shifting network to implement AFC 2
control.
(6)
Vertical scanning signal processing
The vertical oscillation signals output from Pin 24 of TB1238AN are added to the vertical
scanning saw tooth wave signal output terminal Pin 4 of vertical scanning module TA8403K
via R911. Vertical scanning saw tooth wave signals are formed with the differentiation by
driving the internal differential amplifier. Finally, saw tooth wave signals are output from Pin
2 and added to deflection coil. Vertical deflection of the electron beam is generated to
implement the vertical scanning.
25
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