| 摘要 |
PURPOSE:To improve an accuracy in sensing of temperature by a method wherein an energization for an eddy current type sheath heater is controlled with reference to a result of comparison between an output of a sensor unit for sensing a temperature at a bottom part of a pan and an output from a temperature setting unit in an electric heater provided with a temperature adjusting function. CONSTITUTION:When a temperature of a thermistor TH in a sensor 13 for sensing a temperature of bottom part of a pan is low, a resistance value is high, an electric potential of an input terminal (+) of a comparator 12 becomes higher than that of an input terminal (-), and then an output terminal of the comparator 12 is opened. Due to this fact, an electric current is flowed to the base terminal of a transistor Q through resistors R4 and R5 to turn on the transistor Q, a gate current of a bilateral thyristor SCR is flowed through a resistor 7, the thyristor SCR is turned on and the sheath heater 2 is energized. when a temperature of the thermistor TH is increased, an energization of the sheath heater 2 is stopped through a reversing of the comparator 12. With this arrangement, a sensing accuracy is improved under a sheathing of radiation heat from the sheath heater. |
