Samsung BD-C8200, Service Manual

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Schematic Diagrams
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7-2 Power
7-2-1 About S.M.P.S (Ringing Choke Converter Method)
Terms
1) 1st : Common power input to 1st winding.
2) 2nd : Circuit followings output winding of transformer.
3) f (Frequency) : Switching frequency (T : Switching cycle)
4) Duty : (Ton/T) x 100
7-2-2 Circuit description [FLY-Back RCC(Ringing Choke Converter)] Control
(a) AC Power Rectification/Smoothing Terminal
1) BD01 ~ 04 : Convert AC power to DC(Wave rectification).
2) C1S05B : Smooth the voltage converted to DC.
3) L1S01, C1S03, C1S04 : Noise removal at power input/output.
4) R1S02 : Rush current limit resistance at the moment of power cord insertion.
Without P1S02, the bridge diode might be damaged as the rush current increases.
Fig. 7-1
Fig. 7-2
(b) SNUBBER Circuit : D1S10, C1S10, R1S10
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=-L1 xdi/dt. L1 : Leakage Induction)
A very high residual voltage exist on both terminals
of IC1 because dt is a very short.
2) SNUBBER circuit protects IC1 from damage
through leakage voltage suppression by RC,
(Charges the leakage voltage to DIS10 and CIS10
and discharges to R1S10).
(c) IC1S01 Vcc circuit
1) ICIS01, RIS05, RIS07,RIS08 : ICIS01 driving resistance (ICIS01 works through driving resistance at power
cord in)
2) ICIS01 Vcc : RIS05, RIS07, RIS08
q
Use the output of transformer as Vcc,because the current starts to flow into transformer while ICIS01 is
active
w
Rectify to DIS07 and smooth to CIS09.
e
Use the output of transformer as ICIS01 Vcc : The loads are different before and after ICIS01 driving.
(Vcc of ICIS01 decreases below OFF voltage , using only the resistance dut to lode increase after ICIS01
driving.)