| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a switching power supply for reducing the number of components, and effectively improving the power supply efficiency. <P>SOLUTION: The switching power supply is provided with switching circuits (S1-S4) for converting a DC input voltage into AC power, a transformer (T) having a primary winding supplied with the AC power, first rectifiers (D21, D22) for rectifying the AC power induced to a secondary winding in the transformer and converting it to DC power, second rectifiers (D31, D32) having anodes connected to cathodes of the first rectifiers, and a capacitor (C) connected between the cathodes of the second rectifiers and a node at a predetermined potential and functioning as an auxiliary power supply for a predetermined load (F). A surge is generated at the cathodes of the first rectifiers (D21, D22) of the secondary side during a switching operation, and supplied to the capacitor (C) through the second rectifiers (D31, D32). The load (F) utilizes power charged to the capacitor as a working power supply. <P>COPYRIGHT: (C)2007,JPO&INPIT |
