| 摘要 |
<p>A switching power supply circuit is disclosed which allows selective use of a switching element having a comparatively low voltage withstanding property and a low current capacity and can be produced in a low lost and with a small size. Upon starting of power supply, the switching frequency of the switching element is raised by a soft starting circuit to increase a period of time until a secondary side DC output voltage reaches a steady level thereof. As a result, the levels of a resonance voltage and a collector current obtained when the switching element starts its switching operation are suppressed.</p> |
