摘要 |
A switching power supply circuit ready for worldwide use is disclosed which suppresses a variation of a pulse voltage to be fed back when the alternating-current input varies. The switching power supply circuit includes a composite resonance type converter of a switching frequency control scheme wherein a voltage resonance pulse voltage generated in a primary side voltage resonance converter is fed back to a rectification diode through a high speed diode and an inductance or a transformer. An active clamp circuit is provided on the primary side to clamp the voltage resonance pulse voltage. <IMAGE> |