Samsung DVD-R155 Service Manual page 101

13. Circuit Operating Descriptions
13-1 Power
13-1-1 About S.M.P.S (ringing choke converter methol)
◆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
13-1-2 Circuit description [FLY-Back RCC(Ringing Choke Converter)] Control
(a) AC Power Rectification/Smoothing Terminal
1) PADT1 : Convert AC power to DC (Wave rectification).
2) PRCU1 : Smooth the voltage converted to DC.
3) PALT4, PALT2, PACT1, PACT2 : Noise removal at power input/output.
4) PLRU1 : Rush current limit resistance at the momemt of power cord insertion.
: Without PLRU1, the bridge diode might be damaged as the rush current increases.
Samsung Electronics
Fig. 13-1
13-1