Circuit Operating Descriptions
13-32
Samsung Electronics
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. 13-28 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. 13-29 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 DVD-V5450
Page 23: ...Reference Information 14 12 Samsung Electronics Fig 14 14 Mecha Timing Chart Kaiser II ...
Page 37: ...Reference Information 14 26 Samsung Electronics MEMO ...
Page 49: ...Product Specification 2 12 Samsung Electronics MEMO ...
Page 109: ...Operating Instructions 12 60 Samsung Electronics MEMO ...
Page 237: ...Troubleshooting 5 34 Samsung Electronics MEMO ...
Page 247: ...Exploded View and Parts List 6 10 Samsung Electronics MEMO ...
Page 263: ...Block Diagram 8 2 MEMO Samsung Electronics ...
Page 265: ...PCB Diagrams 10 2 Samsung Electronics 10 1 VCR Main PCB COMPONENT SIDE ...
Page 266: ...PCB Diagrams 10 3 Samsung Electronics CONDUCTOR SIDE ...
Page 267: ...PCB Diagrams 10 4 Samsung Electronics 10 2 DVD Main PCB COMPONENT SIDE ...
Page 268: ...PCB Diagrams 10 5 Samsung Electronics CONDUCTOR SIDE ...
Page 270: ...9 1 9 Wiring Diagram Samsung Electronics ...
Page 271: ...Wiring Diagram 9 2 MEMO Samsung Electronics ...