| 摘要 |
PURPOSE:To averte light-exposure of an X-ray film due to the unnecessary residual X-ray by shortening to the most the strating-up time of the high-voltage wave form applied onto an X-ray tube by reducing the internal impedance of the X-ray tube immediately after X-ray scanning as far as possible. CONSTITUTION:The heating voltage stabilized by a stabilizer 20 is corrected in the tube voltage by a space-charge compensating transformer 21 and applied onto the heating resistor 22 for selecting the tube current. The standard heating voltage Vf equal to the heating voltage Ve corresponding to the set tube voltage is applied onto a switching device 23, similarly in the concrete example described in the above, and Ve is applied onto the primary side of a filament heating transformer 11 by the timing signal of a timing circuit 24 during heating. The timing circuit 24 consists of a monostable multifilament vibrator circuit and the circuit which is driven so that the switching device 23 applies Vf, switched from Ve, onto the primary side of the filament heating circuit 11 only during the time when the pulse is transmitted from the monostable vibrator circuit. |
