Circuit Operating Descriptions
7-24
4) FM DEMODULATOR
The FM demodulator consists of a stable mono multivibrator balanced modulator (BM) and a LPF. The FM
demodulator circuit first converts the FM signal to a pulse width modulator signal. Then the circuit smoothes the
PWM signal to demodulate the video signal. This demodulated signal is fed to the LPF to remove its FM carrier
component and any other harmonics. The demodulated luminance is applied to the 3.5MHz LPF through main
deemphasis circuit. To reduce demodulation noise, the output of the 3.5MHz LPF is applied to a non-linear deem-
phasis circuit through YNR circuit.
5) Main De-emphasis Circuit
Before modulation, main emphasis was performed. Because the high frequency components of video signal were
boosted more than the low frequency components in the recording mode, main deemphasis must be performed to
obtain a normal video signal. That is this circuit returns the emphasized high frequency component to the original
value.
6) Non Linear De-Emphasis Circuit
This circuit is the counter part of the dynamic pre-emphasis circuit during recording. The characteristics are also
the opposite of those in recording.
7) Drop Out Compensator/YNR Circuit
This circuit compensated for missing parts of the FM signal due to dust, dirt on the tape or irregular tape coating,
etc. The clamped video signal is supplied to the CCD 1H circuit. The 1H delayed video signal from CCD block is
also supplied to the 6MHz LPF to reject the sampling noise of CCD IC.
Then, the output of LPF is applied to Pin 43 of video IC. When the DOC detector detects the FM loss, a 1H
delayed video signal is added in place of the missing signal.
8) Noise Canceller Circuit
The noise canceller circuit removes the high frequency noise contained in the video signal which has the reverse
characteristics of the detail enhance in the recording mode. The output of the noise canceller circuit is supplied to
the Luminance and Chrominance mixer circuit. The mixed chroma and luminance signal are then output at Pin
61.
Содержание SV-DVD40
Страница 82: ...Circuit Operating Descriptions 7 7 Fig 7 12 Block Diagram ...
Страница 116: ...Circuit Operating Descriptions 7 41 3 Block Diagram Fig 7 38 LA70100M Block Diagram ...
Страница 141: ...VCR Deck Operating Description 8 12 Samsung Electronics Fig 8 14 Mecha Timing Chart ...
Страница 156: ...Samsung Electronics 11 1 11 Wiring Diagram ...
Страница 158: ...Schematic Diagrams 12 2 Samsung Electronics 6 1 S M P S ...
Страница 159: ...Schematic Diagrams Samsung Electronics 12 3 6 2 Power Drive ...
Страница 160: ...Schematic Diagrams 12 4 Samsung Electronics DT701 6 3 Display Function ...
Страница 161: ...Schematic Diagrams Samsung Electronics 12 5 6 4 System Control Servo ...
Страница 162: ...Schematic Diagrams 12 6 Samsung Electronics 6 5 A V ...
Страница 163: ...Schematic Diagrams Samsung Electronics 12 7 6 6 Hi Fi ...
Страница 164: ...Schematic Diagrams 12 8 Samsung Electronics 6 7 A2 NICAM ...
Страница 165: ...Schematic Diagrams Samsung Electronics 12 9 6 8 SECAM Option ...
Страница 166: ...Schematic Diagrams 12 10 Samsung Electronics 6 9 OSD VPS PDC ...
Страница 167: ...Schematic Diagrams Samsung Electronics 12 11 6 10 TM ...
Страница 168: ...Schematic Diagrams 12 12 Samsung Electronics 6 11 Input Output ...
Страница 169: ...Schematic Diagrams Samsung Electronics 12 13 6 12 DVD AV Decoder ...
Страница 170: ...Schematic Diagrams 12 14 Samsung Electronics 6 13 DVD Servo ...
Страница 171: ...Schematic Diagrams Samsung Electronics 12 15 6 14 DVD Audio Video ...
