Abstract
For driving a resonant load, for instance an induction heater, a voltage-source inverter or a current-source inverter has been used. It can not operate as a zero-current-switching (zcs) inverter or a zero-voltage-switching (zvs) inverter unless the operating frequency of the inverter is equal to the resonant frequency of the resonant load.
In this paper, a new adjustable frequency quasi-resonant inverter circuit for a resonant load is proposed. The present inverter operates with soft-switching, according as the power source is separated from the resonant circuit during the reverse current modes. It can drive a resonant load that includes an iron-core matching transformer, because the D. C. component of the output current is suppressed by a D. C. blocking capacitor in series to the load. The present inverter has a feature that the output frequency and the output current are adjustable independently. Therefore, the output frequency is controllable on condition that the output power is fixed.
