| 摘要 |
<p>A power supply circuit has a so-called composite resonance type switching converter equipped with a primary resonance circuit for forming a voltage resonance type converter at a primary side (N1) and a secondary resonance circuit comprising a secondary winding and a secondary parallel resonance capacitor at a secondary side (N2,N3). The secondary side is equipped with active clamp means (C3,DD2) for stabilizing a DC output low voltage taken out from an intermediate tap (N3) of the secondary winding to control the conduction angle of an auxiliary main switching element (Q2) in accordance with the level of the DC output low voltage, whereby the power loss due to the cross-regulation of the DC output low voltage can be reduced, and the power conversion efficiency can be enhanced. <IMAGE></p> |
