Circuit Operating Descriptions
7-3
(2) Circuit description (FLY-Back PWM (Pulse Width Modulation control)
(a) AC Power Rectification/Smoothing Terminal
1) D1SS01, D1SS02, D1SS03, D1SS04 : Convert AC power to DC(Wave rectification).
2) C1SS10 : Smooth the voltage converted to DC.
3) L1SS01, L1SS02, C1SS01, C1SD02 : Noise removal at power input/output.
4) R1SS01 : Rush current limit resistance at the moment of power cord insertion.
- Without R1SS01, the bridge diode might be damaged as the rush current increases.
(b) SNUBBER Circuit : R1SD11, R1SD13, C1SD12, C1SD16, D1SS11
0
Vswitch
dt
Toff
t
Inverted power
by leakage
inductance
Fig. 7-7
1) Prevent residual high voltage at the terminals of
switch during switch off/Suppress noise.
High inverted power occurs at switch off, because of
the 1st winding of transformer :
(V= LI xdi/dt. LI : Leakage Induction)
A very high residual voltage exists on both terminals
of SCS11A because dt is a very short.
2) SNUBBER circuit protects SCS11A from damage
through leakage voltage suppression by RC,
(Charges the leakage voltage to D1SS11 and C1SD12
and discharges to R1SD11 and R1SD13).
3) C1SS16 : For noise removal
(c) IC1SS2 Vcc circuit
1) R1SR01, R1SR02, R1SR03 : IC1SS2 driving resistance
(IC1SS2 works through driving resistance at power cord in)
2) IC1SF01 Vcc : R1SS08, D1SF02, C1SF02
Œ
Use the output of transformer as Vcc, because the current starts to flow into transformer while IC1SS2 is
active.
´
Rectify to D1SF02 and smooth to C1SF02.
ˇ
Use the output of transformer as IC1SS2 Vcc : The loads are different before and after IC1SS2 driving.
(Vcc of IC1SS2 decreases below OFF voltage, using only the resistrance due to load increase after IC1SS2
driving.)
Summary of Contents for SV-DVD40
Page 82: ...Circuit Operating Descriptions 7 7 Fig 7 12 Block Diagram ...
Page 116: ...Circuit Operating Descriptions 7 41 3 Block Diagram Fig 7 38 LA70100M Block Diagram ...
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Page 158: ...Schematic Diagrams 12 2 Samsung Electronics 6 1 S M P S ...
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Page 161: ...Schematic Diagrams Samsung Electronics 12 5 6 4 System Control Servo ...
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Page 166: ...Schematic Diagrams 12 10 Samsung Electronics 6 9 OSD VPS PDC ...
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Page 168: ...Schematic Diagrams 12 12 Samsung Electronics 6 11 Input Output ...
Page 169: ...Schematic Diagrams Samsung Electronics 12 13 6 12 DVD AV Decoder ...
Page 170: ...Schematic Diagrams 12 14 Samsung Electronics 6 13 DVD Servo ...
Page 171: ...Schematic Diagrams Samsung Electronics 12 15 6 14 DVD Audio Video ...
