| 摘要 |
PROBLEM TO BE SOLVED: To provide a resonance switching power supply unit capable of attaining a stable operation. SOLUTION: A load RL is connected to the output of a piezoelectric transformer 1, and a drive circuit 12 is connected to the input thereof. There is provided an impedance conversion circuit 13 for making the impedance inductive, when a piezoelectric transformer 1 is viewed from a drive circuit 12. As a result, the impedance, when the piezoelectric transformer 1 is viewed from a drive circuit 12, becomes inductive, and a switching device can be turned on and off in an inductive area of frequency higher than the resonance frequency of the resonance switching power supply unit, thereby attaining a stable operation. |
