| 摘要 |
PROBLEM TO BE SOLVED: To prevent the power consumption and heat generation in a resistor from getting larges in the case of supplying a power through the resistor at the time of starting energizing. SOLUTION: An AC power given from a commercial power source 21 through a power source switch 22 is directly supplied to the input end 26a of a triac 26, and voltage-dropped by an automatic transformer 24 so as to be supplied to the input end 28a of a triac 28. By turning on the triac 28 according to a control signal B outputted from a switch control circuit 30 first at the time of starting the energizing, the AC power having a low voltage value is supplied to a heater 18 to perform the preheating of the heater 18. Thereafter, the triac 26 is turned on according to a control signal A outputted from the circuit 30 instead of the signal B, so that the AC power having a high voltage value is supplied to the heater 18. |
