Circuit Operating Descriptions - Toshiba D-VR3SU Service Manual

7. Circuit Operating Descriptions

7-1 Power
7-1-1 About S.M.P.S
+
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
7-1-2 Circuit description Control
(a) AC Power Rectification/Smoothing Terminal
1) BD01 : Convert AC power to DC (Wave rectification).
2) CIS01 : Smooth the voltage converted to DC.
3) L1S02, C1S04, C1S05 : Noise removal at power input/output.
4) R1S04 : Rush current limit resistance at the momemt of power cord insertion.
· Without R1S04, the bridge diode might be damaged as the rush current increases.
(b) SNUBBER Circuit : R1S02, R1S03, C1S08, C1S07, D1S05
Transformer
(Np)
+
(Vp)
–
Switch
+
Vs switch
–
ON/OFF Control
I switch
(Ns)
+
(Vs)
–
+
Fig. 7-1
Vout
REGULATOR
Vreg
7-1