| 摘要 |
PROBLEM TO BE SOLVED: To provide an induction heater which can heat aluminum with less semiconductor losses. SOLUTION: The induction heater comprises a series connector of a first and a second rectifying diodes which are connected in parallel to a series connector of a first and a second semiconductor switches, a series connector of a heating coil and a resonance capacitor connected between terminals of the first or the second semiconductor switches, and a first and a second clamp capacitors which are respectively connected in parallel to the first and the second rectifying diodes. A series circuit of a commercial power source and a choke coil is connected between a connection point of the first and the second semiconductor switches and a connection point of the first and the second rectifying diodes, the first and the second semiconductor switches are driven by the predetermined drive frequency, and the frequency of the resonance current of the resonance circuit comprising the heating coil and the resonance capacitor is set to the frequency at least twice the drive frequency. The induction heater capable of facilitating the cooling configuration can be realized by smoothing the power supplied to a work to be heated, and equally dividing the element duty. |
