Circuit Operating Descriptions
7-32
5) PB AMP
The diagram to the left is the playback amp and the gain input/output are as
follows.
Av = 1 +
The playback characteristic of VHS format can be satisfied by using Z
1
, Z
2
in
the above equation.
PB amp gain should be designed to be approximately 45dB (1KHz).
Z1
Z2
INPUT
PB AMP
OUTPUT
Fig. 7-28 PB Amp
Z
2
Z
1
Z
2
Z
1
~
~
6) REC AMP
The diagram to the left is REC AMP. The amp gain is approximately 14dB.
R
1
and R
2
that determine the gain is located inside the IC.
It is uniform and independent to frequency. Frequency characteristics should
be considered when designing rec amp. The REC amp should be the opposite
to playback characteristics.
OUTPUT
PB AMP
INPUT
R1
R2
Fig. 7-29 REC Amp
7) OSC (Oscillation)
Oscillation frequency is 70KHz. It’s size is approximately 40Vp-p. it operates on recoed mode. It is supplied to
audio erase head and full erase head used to erase already recorded signals.
Also, it conducts “AM (Amplitude Modulation)” using oscillation signals.
8) BIAS Control
Output level changes according to the impedance of F/E, A/E and R/P head connected to the coil.
9) 60KHz HPF
There must be standard signal for bias control and that signal uses HPF only to obtain oscillation signal that
comes through R/P head.
10) S/W
The switch opens when recording, shorts during playback and exterior transister is used.
Summary of Contents for SV-DVD50
Page 26: ...Exploded View and Parts List 3 10 Samsung Electronics MEMO ...
Page 88: ...VCR Deck Operating Description 8 12 Samsung Electronics Fig 8 14 Mecha Timing Chart ...
Page 102: ...VCR Deck Operating Description 8 26 Samsung Electronics MEMO ...
Page 109: ...Circuit Operating Descriptions 7 7 Fig 7 12 Block Diagram ...
Page 143: ...Circuit Operating Descriptions 7 41 3 Block Diagram Fig 7 38 LA70100M Block Diagram ...
Page 158: ...Block Diagram 10 2 Samsung Electronics MEMO ...
Page 159: ...Samsung Electronics 11 1 11 Wiring Diagram ...
Page 160: ...Block Diagram 11 2 Samsung Electronics MEMO ...
Page 162: ...Schematic Diagrams 12 2 Samsung Electronics 6 1 S M P S ...
Page 163: ...Schematic Diagrams Samsung Electronics 12 3 6 2 Power Drive ...
Page 164: ...Schematic Diagrams 12 4 Samsung Electronics DT701 6 3 Display Function ...
Page 165: ...Schematic Diagrams Samsung Electronics 12 5 6 4 System Control Servo ...
Page 166: ...Schematic Diagrams 12 6 Samsung Electronics 6 5 A V ...
Page 167: ...Schematic Diagrams Samsung Electronics 12 7 6 6 Hi Fi ...
Page 168: ...Schematic Diagrams 12 8 Samsung Electronics 6 7 A2 NICAM ...
Page 169: ...Schematic Diagrams Samsung Electronics 12 9 6 8 SECAM Option ...
Page 170: ...Schematic Diagrams 12 10 Samsung Electronics 6 9 OSD VPS PDC ...
Page 171: ...Schematic Diagrams Samsung Electronics 12 11 6 10 TM ...
Page 172: ...Schematic Diagrams 12 12 Samsung Electronics 6 11 Input Output ...
Page 173: ...Schematic Diagrams Samsung Electronics 12 13 6 12 DVD AV Decoder ...
Page 174: ...Schematic Diagrams 12 14 Samsung Electronics 6 13 DVD Servo ...
Page 175: ...Schematic Diagrams Samsung Electronics 12 15 6 14 DVD Audio Video ...
Page 176: ...Schematic Diagrams 12 16 Samsung Electronics MEMO ...