| 摘要 |
PURPOSE:To perform wide power setting rarely generating a timing drift against the change of the input power and the change of the input voltage, keeping the drive timing of a switching element constant, and capable of reducing the circuit loss such as the switching loss. CONSTITUTION:A resonance voltage detecting circuit 12 detecting the resonance voltage of an inverter circuit 19, a resonance voltage smoothing circuit 13 smoothing the resonance voltage, and an excitation pulse signal generating circuit 16 feeding the periodic excitation pulse signal to a switching element 8 are provided in a control circuit 20. The output of the resonance voltage detecting circuit 12 and the output of the resonance voltage smoothing circuit 13 are compared, and the result is inputted to the excitation pulse signal generating circuit 16 to generate the excitation pulse signal. |
