| 摘要 |
PURPOSE:To substantially reduce the rush current at the time of energizing the heater by providing a control circuit which is capable of impressing tungsten heating elements with a time lag between one and another at the start on the basis of a signal from a temperature sensor at a heater heating a vaporizing chamber. CONSTITUTION:A tungsten heating element 3a has a heating capacity reduced to about one half, that is, the resistance increased to two times, compared with conventional tungsten heating elements, so that the rush current Ia is reduced to about one half. When subsequently the temperature in a vaporizing chamber 4 rises, causing the signal inputted to a port P5 from a temperature sensor 7 to exceed a value corresponding to a temperature Tp, a signal outputted from a port P4 turns on a transistor TR5 so as to apply AC power to a tungsten heating element 3b in the same manner as the power supply to the tungsten heating element 3a. The heating of the vaporizing chamber 4 is thus accelerated, hence completion of the preliminary heating of the vaporizer without protraction. |
