| 摘要 |
PROBLEM TO BE SOLVED: To provide an induction heating cooker preventing offensive sound continuously changing its pitch when a plurality of induction heating devices placed near to each other are heated, with reduced loss of an inverter circuit. SOLUTION: An inverter circuit 35 is composed of IGBT's 34a, 34b, a heating coil 23, and a resonant capacitor 37. A terminal voltage of the resonant capacitor is detected as a second signal Sb. A frequency conversion circuit 44 drives the IGBT 34 through a driving part 39, and its signal is turned into a signal Sa. A microcomputer 40 sets a frequency alteration when the phase difference and the set value of phase difference of both signals Sa, Sb are not in allowable range. By the above, the setting of the frequency alteration becomes not continuous but digital within the allowable range, and continuous change of the interference sound between the devices is prevented, and the loss is reduced by eliminating overshoot. |
