Circuit Operating Descriptions - Samsung DVD-R157 Service Manual

13. Circuit Operating Descriptions

13-1 Power
13-1-1 About S.M.P.S (Ringing Choke Converter Method)
Vin
◆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, PADT2, PADT3, PADT4 : Convert AC power to DC (Wave rectification).
2) PRCU1 : Smooth the voltage converted to DC.
3) PALT1, PALT2, PACT1, PACT2 : Noise removal at power input/output.
4) PLRU1 : Rush current limit resistance at the momemt of power cord insertion.
· Without PLRT1, the bridge diode might be damaged as the rush current increases.
Samsung Electronics
+
Switch
+
Vs switch
–
ON/OFF Control
I switch
Transformer
(Np) (Ns)
–
+
(Vp) (Vs)
+
–
Fig. 13-1
Vout
REGULATOR
+
Vreg
13-1