| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a resonance frequency measuring method which prevents a self-arc-suppressing type switching element from breaking down, and can measure the resonance frequency of a resonance circuit with high accuracy, by using an oscillating current waveform output from an inverter. <P>SOLUTION: A high-frequency power supply is equipped with a single-phase output voltage type full bridge inverter 100, wherein two element pairs which are composed of MOSFETs 2, 3 and MOSFETs 8, 9 respectively connected in series, are connected to a DC power supply 1 in parallel, and connection points of MOSFETs of respective element pairs are used as a pair of AC output terminals. In the high-frequency power supply, an inductive impedance 4 and a parallel circuit of a resonance capacitor 5 and a load 200 are connected in series between the pair of AC output terminals. A positive or a negative DC voltage signal is output from the inverter 100 for a prescribed period, and then the output current of the inverter 100 is oscillated, by controlling the MOSFETs 2, 3, 8 and 9 to be turned on/off so that the output voltage becomes zero; and the oscillation frequency is measured, thereby obtaining the resonance frequency of the resonance circuit, including the load 200. <P>COPYRIGHT: (C)2008,JPO&INPIT |
