Samsung BD-D5500, Service Manual

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6. Schematic Diagrams
6.2. Power
6.2.1. 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
6.2.2. Circuit descripcotion [FLY-Back RCC(Ringing Choke Converter)] Control
1) AC Power Rectification/Smoothing Terminal
a) BD01 ~ 04 : Convert AC power to DC(Wave rectification).
b) C1S05B : Smooth the voltage converted to DC.
c) L1S01, C1S03, C1S04 : Noise removal at power input/output.
d) 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.
2) SNUBBER Circuit : D1S10, C1S10, R1S10
a) 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.
b) SNUBBER circuit protects IC1 from damage through leakage voltage suppression by RC, (Charges the leakage voltage to DIS10 and CIS10 and discharges to R1S10).
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