| 摘要 |
PURPOSE: To improve the uniformity of the heating, by adjusting the duration of a control cycle in the periodical driving of a microwave radiation source for performing the heating with the various power levels of the microwave, and the revolution time of a rotary bottom plate. CONSTITUTION: A microwave radiation source 20 is pulse driven by a control unit 15, or is periodically switched on and off, to apply the microwave of the power level lower than the maximum power level, to a heat chamber 3. On the other hand, a rotary bottom plate of the heat chamber 3 is driven by a periodic motor at a constant speed. Further the power level is determined on the basis of the interrelation of the periods of the driving and the stop of the control cycle. Further the duration T of the control cycle relating to the revolution time of the bottom plate is simultaneously determined so that the rotary sector part corresponding to the driving period of the radiation source 20, is almost uniformly distributed to the whole bottom plate during the heating process. The control is performed to satisfy that T=T1 +T2 , and the power level P=(T1÷T)×MPmax, when the driving period with the maximum output (MPmax) from the radiation source 20, is T1 , and the stop period where the output is 0, is T2 .
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