16
6. Signal flow of the SECAM colour in the playback mode
The output signal (mixed the luminance and colour) from head is input to the PREAMP IC. This signal is amplified by about
60dB (approximately 1000 times) by the preamp IC. The signal from the PREAMP IC is fed to 1.1MHz BPF circuit (consists
of CL421, RL410, LL408, CL408 and RL411). The luminance signal is eliminated by the 1.1MHz BPF circuit. This output
signal is fed to Pin 18 of ICL01. The output at Pin 18 is input to a 1.1MHz BPF and the unwanted signal is eliminated. The
signal from 1.1MHz BPF circuit is input to the PB EQ circuit. This signal is flattened by this circuit. The flattened signal is
then input to the Limiter circuit. In this circuit, the signal is limited. The limited signal is fed to the X2 circuit to give the signal
with double frequency. The doubled frequency signal output is fed to a 2.2MHz BPF circuit to eliminate the unwanted
signal, and then is input to another X2 circuit. Therefore the new signal has a quandrupled frequency. After the quadrupled
signal is input to a 4.3MHz BPF in order to eliminate the unwanted signal, it is fed to Pin 26 of ICL01. The output signal at
Pin 26 is input to Pin 1 of ICL02 and the 12dB AMP circuit. The signal input to Pin 1 of ICL02 is used to detect whether the
signal is SECAM or non-SECAM. The other signal is input to the 12dB AMP circuit. The 12dB AMP output signal is fed to
the Limiter circuit through Pin 24 of ICL01.
In the Limiter circuit, the amplitude of the signal may be limited. The signal from the Limited circuit is input to the PB SYNC
GATE circuit to eliminate a noise from the SYNC part, and then fed to Pin 6 of ICL01 through the 4.3MHz BPF and the PB
BELL circuit. The signal from Pin 6 is input to Pin 8 through a 2.1MHz Trap to remove the spurious components. The signal
at Pin 8 is fed to Pin 11 of ICL01 through 6dB AMP circuit.
The signal at Pin 11 is input to Pin 29 of IC301 (LA7437: Y/C IC).
PB
AMP
PB Color
from PREAMP
1.1MHz
BPF
1.1MHz
BPF
PB
EQ
X2
2.2MHz
BPF
X2
Limiter
4.3MHz
BPF
12dB
AMP
Limiter
PB
SYNC GATE
6dB
AMP
ICL02
SECAM
DETECTOR
PB
BELL
4.3MHz BPF
To. pin
E
of IC301
1
PB SECAM
SECAM(H)
2.1MHz
Trap
4.286MHz
Trap
SECAM:HIGH
non-SECAM: LOW
8
=
q
!
)
*
^
BLOCK 6. PB SECAM COLOUR SIGNAL FLOW
Содержание DV-K882SY-AN
Страница 68: ...SECTION 8 CIRCUIT DIAGRAM 8 1 CONNECTION DIAGRAM 66 ...
Страница 69: ...8 2 POWER CIRCUIT 67 ...
Страница 70: ...8 3 LOGIC CIRCUIT 68 ...
Страница 71: ...8 4 MAIN CIRCUIT 69 ...
Страница 72: ...8 5 VIDEO CIRCUIT 70 ...
Страница 73: ...8 6 HEAD AMP CIRCUIT 71 ...
Страница 74: ...8 7 SECAM CIRCUIT 72 ...
Страница 75: ...8 8 Hi Fi AUDIO CIRCUIT 73 ...
Страница 76: ...8 9 PIF CIRCUIT 74 ...
Страница 77: ...8 10 IF MODULE CIRCUIT 75 ...
Страница 78: ...8 11 A V SCART CIRCUIT 76 ...
Страница 79: ...8 12 OSD CIRCUIT PDC CIRCUIT 77 ...
Страница 80: ...8 13 REMOCON CIRCUIT 78 ...