To provide the detuning detector of a resonance circuit capable of detecting normality or abnormality of the resonance circuit connected with an inverter.
The detuning detector of a resonance circuit comprises an inverter 2 for supplying AC power, a resonance circuit 3 being supplied with AC power from the inverter 2, a first current measuring means (current detector 6) for measuring a current flowing through a loop circuit 5 of the inverter 2, a second current measuring means (current detector 11) for measuring a current flowing through the resonance circuit 3, a section 21 for operating the power factor of the resonance circuit 3 based on a current value I1 obtained from the first current measuring means and a current value I2 obtained from the second current measuring means, and a section 23 for judging whether the resonance circuit 3 is operating abnormally or not by comparing the power factor outputted from the power factor operating section 21 with a reference value which is regulated depending on the value of power being supplied to the resonance circuit 3.
Arihara Koichi
Matsushima Tetsuo