| 摘要 |
<p>A microwave oven includes a gas sensor for detecting a cooking condition. The resistance value of the gas sensor varies in response to the concentration of the gas generated from the foodstuff being cooked in the microwave oven. A resistance-to-frequency converter including an astable multivibrator is provided for converting the variation of the resistance value of the gas sensor into a frequency signal. A cooking constant setting circuit is provided for developing a signal of a reference frequency in response to a menu to be conducted. The frequency signal, indicative of the resistance value of the gas sensor, obtained by the resistance-to-frequency converter is compared with the reference frequency to terminate the cooking operation when the frequency signal reaches the reference frequency. * * * * * * * * * *</p> |
