Patent ID: 8809752

Claim:
A boosting circuit, comprising: a switch element that generates a first alternating current voltage having a first frequency from a direct current voltage; a first coil that generates a magnetic field around the first coil with a flow of the first alternating current voltage having the first frequency in the first coil; a second coil cumulatively connected in series to the first coil, and the direct current voltage from a rectifying circuit is input at a connection point between the first coil and the second coil, such that the first coil and the second coil have a mutual inductance to induce an eddy current in an object with the magnetic field to inductively heat the object; a capacitor connected in parallel across the first coil, the second coil, and the connection point between the first coil and the second coil at which the direct current voltage is input; and a controller that controls a switching timing of the switch element based on an electrical measurement made across the circuit formed by the series connected first and second coils connected in parallel to the capacitor to correct a variation of the mutual inductance of the first coil and the second coil.