摘要 |
A switching power supply apparatus includes first and second switch circuits (S 1 ) and (S 2 ) including switch devices (Q 1 ) and (Q 2 ), diodes (D 1 ) and (D 2 ), and capacitors (Cds 1 ) and (Cds 2 ), and a transformer (T). A first inductor (Lr) is connected in series with a primary winding (Lp) of the transformer (T), and a second inductor (Li) is arranged so that a voltage of a third capacitor (Ca) is applied during an on-period of the first switch circuit (S 1 ). A diode (Di) preventing a reverse current from flowing in the second inductor (Li), and a capacitor (Ci) that is charged by excitation energy stored in the second inductor (Li) and that applies a voltage to the primary winding (Lp) during the on-period of the first switch circuit (S 1 ) are further provided. A capacitor (Cr) is further provided so as to define a closed loop together with the inductor (Lr), the primary winding (Lp), and the second switch circuit (S 2 ).
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