| 摘要 |
A power supply device (200) includes a transformer (T100) including a primary coil (Lp), a secondary coil (Ls), and a tertiary coil (Lsub); a switching element (Qsw) connected via the primary coil to a direct-current power supply (DCin); a first rectifying-and-smoothing circuit (301) rectifying and smoothing a voltage generated in the secondary coil; a control circuit (101) turning on and off the switching element; a second rectifying-and-smoothing circuit (302) rectifying and smoothing a voltage generated in the third coil to generate a driving voltage (Vcc) for the control circuit; and a starting circuit (400) including a first transistor (Q1), a first resistor (R1), and a first capacitor (C1) connected in series between the direct-current power supply and a ground (GNDin), a second transistor (Q2) connected between the direct-current power supply and the second rectifying-and-smoothing circuit, and a turn-off unit (L1) turning off at least the second transistor out of the first transistor and the second transistor when the first capacitor is charged to a predetermined voltage. |
