| 摘要 |
PURPOSE:To provide possibility of heating an object with comparatively small heated area by furnishing a means to sense the applicable area mating with the heating area of the heating coil, and installing a means to set the sensing sensibility of the sensing means upon adjustment. CONSTITUTION:When a push button switch of a load sensing level changeover circuit 29 is closed, a signal at L level is emitted to set the sensing sensitivity of a load sensing circuit 25 at a low value. When this load sensing circuit 25 is set at low value, an H level signal is given in case the area ratio of the heated area to the surface areas of a top plate exceeds 30% to actuate a pulse width modulation circuit 21 and a driver circuit 15, and an inverter circuit 3 is actuated to perform heating of the object placed on the top plate. When the heating is finished, the power supply is turned off, and if it is turned on again, the load sensing level changeover circuit 29 sets the sensing sensitivity of the load sensing circuit 25 automatically at a high value. |
