Induction heating apparatus
AssigneePanasonic Intellectual Property Management Co., Ltd.
InventorsTakeshi Kitaizumi, Yoichi Kurose, Akira Kataoka
Life of this patent
Estimating the term…
Abstract
It is an object of the present invention to provide an induction heating apparatus that can enable a plurality of heating coil to perform heating by sharing a inverter having semiconductor switches in use, thereby adjusting a power without increasing losses of the semiconductor switches so much with respect to the respective heating coils, the present invention being configured such that the inverter alternately outputs drive signals respectively having each of two operating frequencies to the plurality of heating coils in every predetermined operation lapse of time and the plurality of heating coils are respectively connected to capacitance circuits in the inverter to have the different frequency characteristics.
Claims15
An induction heating apparatus comprising:
- a smoothing circuit to which a rectified power from an AC power supply is input;
- an inverter in which the smoothed power is input to a set of semiconductor switch circuits from the smoothing circuit, and which is configured to output a periodic drive signal having a first operating frequency during a first time period, and a second operating frequency during a second time period;
- a plurality of heating coils which are supplied with the drive signals from the inverter, wherein each of the plurality of heating coils is connected to one of a plurality of capacitance circuits so that each heating coil has a resonant frequency that matches one of the two operating frequencies;
- and
- a control portion for controlling the operating frequencies and the operation period of time to drive the semiconductor switch circuit, wherein the control portion is configured to select the first operating frequency and the second operating frequency to simultaneously set a first average power delivered to a first heating coil to a first power value, and a second average power delivered to a second heating coil to a second power value, to thereby heat a first load disposed on the first heating coil with the first average power and to heat a second load disposed on the second heating coil with the second average power.
Dependencies are inferred from the claim text.