Circuit Operating Descriptions - Samsung DVD-R130 Service Manual

13. Circuit Operating Descriptions

13-1 Power
13-1-1 About S.M.P.S (ringing choke converter methol)
+
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 : 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 PLRU1, the bridge diode might be damaged as the rush current increases.
(b) SNUBBER Circuit : PSRZ1, PSRZ2, PSCX1, PSCZ2, PSDZ1
Samsung Electronics
Transformer
(Np)
+
(Vp)
–
Switch
+
Vs switch
–
ON/OFF Control
I switch
(Ns)
+
(Vs)
–
+
Fig. 13-1
Vout
REGULATOR
Vreg
13-1