These functions are performed by the integrated circuit TDA8351 (ICF1). This is a power
amplifier with a bridge output that allows the vertical deflection coils to be connected
directly to pins 4 and 7. The resistances RF9/RF10, which provide pin 9 with the
necessary feedback signal, are placed in series.
The differential input circuit (pins 1/2) is driven by the voltage formed across RF3/RF4 for
the symmetrical driving currents provided by ICC1.
Pin 8 is an output which switches to the value H at vertical flyback. This signal is
connected to pin 9 of ICC1 and is used to protect the CRT in the event of failure of the
vertical deflection circuits.
Two separate supply voltages are used for the deflection part (pin 3) and for generating
the flyback pulse (pin 6), thereby achieving a high value of efficiency.
The power stage for EW correction consists of transistor TG1 which is driven directly by
ICC1 and whose collector is connected to the injection coil LG2 by means of RG4.
Audio signal processing
The various audio functions are treated by the circuits TDA9870/5A (ICS1), SAA7710T
(ICS4), TDA7467D (ICS5), TDA2616 (ICS2/ICS6), TDA7053AT (ICS3).
" TDA 9870A / TDA 9875A
The integrated circuits have the same basic functions: the version TDA9875A additionally
contains a complete NICAM digital audio decoder.
The audio IF signal from pin 5 of ICC2 is applied to input pin 12. The AM audio signal (in
the case of L/L? standard) is also extracted by way of the transistor TS1 and the low-pass
filter formed by RS34 and CS13 and is taken to input pin 29. A second IF input (pin 10) is
used for the audio signal of the satellite receiver (if present).
All audio functions (demodulation, stereo/NICAM decoding, input/output switching,
volume/tone control, effects) for BG/DK/I/LL? standards are contained in the integrated
circuit and are totally selected and controlled via software.
The audio inputs from the SCART 1 and SCART 2 sockets are connected to pins 33/34
and 36/37 respectively, while the audio input from the front RCA sockets (optional) is
connected to pins 31/32.
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ACEC
