| 摘要 |
PROBLEM TO BE SOLVED: To form gate signals for switching elements in a synchronous rectification circuit using a simple method, extend an on-period as much as possible to reduce a current which flows to diodes connected in parallel with the switching elements during a flywheel period, reduce conduction loss including a switching time from a rectification period to a flywheel period, turn off the switch elements before a reverse current is passed through the switching elements, and enable control of the switching element with less surge voltage for the enhancement of the efficiency of the entire circuit. SOLUTION: The input current of the synchronous rectifying circuit is detected by a current detector 36, and the output current thereof is detected by a current detector 37. The periods during which the detected input current is larger than the detected output current are taken as on-periods of synchronous rectifying elements by signal formation circuits 31 and 34.
|
