| 摘要 |
PURPOSE:To automatically stop heating and automatically cut off power supply by surely detecting a pan absent state in which a pan is not placed on a top plate in an electromagnetic induction heating type cooker. CONSTITUTION:A first condition signal of a first condition detecting circuit which is output when high frequency current fed to a heating coil is larger than a predetermined value, a second condition signal of a second condition detecting circuit which is output when power input current is dropped below a predetermined value, and a third condition signal of a third condition detecting circuit which is output when the phase lag of current with respect to the voltage of a power input portion becomes more than a predetermined value, are employed as the conditions of detecting the absence of a pan. A transistor 76 is driven in response to the output of an AND circuit 74 to which the three signals are input, so as to operate a relay 78. Roughly 100% detection of the absence of the pan is thus carried out and a timer circuit not shown in Figure performs automatic stopping of heating and automatic cutoff of power supply in accordance with an output indicative of the detection of the absence when the time of the absence of the pan continues beyond a predetermined time. |
