| 摘要 |
PROBLEM TO BE SOLVED: To cope with the risk of falling into an element break if main switching elements and a resonance switch are turned off in a state of a large current flow caused by a resonance current, when turning off the main switching elements due to protection operation, while main switching elements Q1-Q4 are ON and a resonance switch Qz is ON.SOLUTION: When one of the main switching element is ON and the resonance switch is ON, instead of instantly turning off the main switch element and the resonance switch, the turn-off is performed surely after the completion of a half period of the resonance operation, so as to avoid breakage in the state of a large current flow caused by the resonance current. Further, when the main switching element is ON, a gate pulse in that period surely switches on the resonance switch, so that the main switching element and the resonance switch are simultaneously turned off. |
