| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a synchronous rectifying circuit that accommodates reduction in the output voltage of a power supply through minor design change. SOLUTION: A drive wire 21 is wound on an existing choke coil 8. Voltage induced in the drive wire 21 is, as it is, utilized as a driving signal for a rectifying switching element 7. The current of the rectifying switching element 7 is detected at a current transformer 12. If a detected signal generated in the secondary winding 14 thereof falls down to a specified level, the rectifying switching element 7 is turned off. A voltage sufficient to turn on the rectifying switching element 7 is supplied only by appropriately changing the number of turns of the drive wire 21, and thus reduction in the output voltage of the power supply can be accommodated by minor design change.</p> |
