| 摘要 |
Provided is a switching power supply device capable of effectively improving power supply efficiency with a small number of parts. The switching power supply device includes: a switching circuits (S1 to S4) for converting DC input power into AC power, a transformer (T) having a primary winding to which the AC power is supplied, first rectifiers (D21, D22) for rectifying the AC power induced by the secondary winding of the transformer into DC power, second rectifiers (D31, D32) having anodes connected to cathodes of the first rectifiers, and a capacitor (C) connected between the cathodes of second rectifiers and a predetermined potential node and functioning as an auxiliary power source of a predetermined load (F). Surge generated at the cathodes of the first rectifiers (D21, D22) of the secondary side during switching is supplied to the capacitor (C) via the second rectifiers (D31, D32). The load (F) uses power charged in the capacitor as an operation power source. |
