摘要 |
PURPOSE:To prevent the damage of a control element due to a reverse recovery current by always delaying the phase of the output current of a high frequency power source which flows a load from the phase of the output voltage of the power source. CONSTITUTION:The current and the voltage of a load Z are respectively detected by a current detector Tc and a voltage detector Tp, and the detected outputs are respectively inputted to a comparator G through a phase regulator Pr, a waveform shaper Wi and a waveform shaper Wv. The output of the comparator G is inputted to a voltage/frequency converter V/F through a low pass filter Lf, the output is applied through a pulse amplifier Pa to control elements Q1, Q2, thereby controlling the ON and OFF thereof. In this manner, the phase of the output current is regulated and controlled to be delayed in the prescribed amount from the phase of the output voltage. |