| 摘要 |
<p>A power supply (2) for converting a plurality of alternating current (AC) and direct current (DC) input line voltages (VA, VB, VC) to a DC output voltage (VOUT) includes a converter (20,22) for converting the input voltages (VA, VB, VC) to an intermediate voltage (V2) at a first node (19); a switching regulator (6) having a power voltage (VP) at a second node (24) for providing a reference voltage (VREF) therefrom, and for providing a switching signal (S) at a third node (26) from the reference voltage (VREF) and a feedback voltage (VF); a circuit (8,78) for electrically interconnecting the first node (19) to the second node (24) whenever the intermediate voltage (V2) exceeds a predetermined voltage; a transformer (10) including a primary winding (30) electrically interconnected with the first node (19), and a secondary winding (32) having a secondary voltage (SV,VS); a feedback circuit (12) cooperating with the transformer (10) for providing the feedback voltage (VF) therefrom; a switching circuit (14) responsive to the switching signal (S) at the third node (26) for switching an electrical current (IP) from the first node (19) through the primary winding (30); and a circuit (16) electrically interconnected with the secondary winding (32) for converting the secondary voltage (SV,VS) to the output voltage (VOUT). <IMAGE></p> |
