| 摘要 |
PROBLEM TO BE SOLVED: To suppress the temperature of a semiconductor switch element from rising and to dispense the attachment of a heat radiator necessary for cooling by stopping the energization to the heat insulating heater in extending the boiling in a device provided with a main heater for boiling water in a pot into a hot water and a heat insulating heater for insulating the heat of the boiled water. SOLUTION: When a voltage is fed from an AC power supply 1, a control circuit 10 closes a relay 6 and turns on a main heater 2 and a semiconductor switch element 7 respectively based on the detection temperature of a thermistor 9 so as to energize a heat insulating heater 3 and boil the water in a pot. When detecting its boiling by the thermistor 9, it turns off the relay 6 and the semiconductor switch element 7 so as to stop the energization to the both heaters 2 and 3. After that, when a boiling extension action is selected by pushing a hot water boiling switch 11 in an operation display 8, it turns off the semiconductor switch element 7 by the detection of the boiling, stop the energization to the heat insulating heater 3, and extends the boiling for a prescribed time by single energization to the main heater 2.
|
