| 摘要 |
PURPOSE:To save a length of the time till a heating condition of the filament reaches a steady state, by providing an initial heating operation control circuit that generates a pulse voltage for a predetermined length of period from the time of starting a heating operation of the filament. CONSTITUTION:The heater comprises a tube current selector 1 to switch a tube current in accordance with a selection of the dial position, a tube current signal generating unit2, a power unit 3 of the switching regulator DC stabilized power source system, a filament transformer 4 and an X-ray 5. In addition to the above, an initial heating control circuit 14 is provided. The initial heating control circuit 14 starts generating a pulse voltage since the time of starting a heating operation of the filament for a predetermined length of period and adding it to an output of the tube current signal generating unit 2. In this way, the initial level of a voltage applied to the filament transformer 4 comes to be higher than the specified level, thus shortening a length of the time reguired until a heating condition of the filament reaches the constant state. |
