| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize an X-ray generating device and make it lightweight by modulating the output of a DC power supply converting an AC current into a DC current at a first period and a second period, boosting it with a transformer and a Cockcroft-Walton booster circuit, then inputting it to an X-ray tube to generate X-rays. SOLUTION: The output of a commercial AC power supply 1 is rectified and filtered by a power supply section 5 to obtain a DC voltage, it is converted into a pulse voltage by a first modulation section 8 provided with a transistor 6 and a clock 7, the period is shortened by a second modulation section 11 provided with transistors 9a-9d and a tube voltage controller 10, and the voltage is stepped up by a transformer 12. The voltage is boosted and rectified into a minus voltage by a Cockcroft-Walton booster 13 which is a 24-stage stack circuit of rectifiers and capacitors, then it is applied to the cathode 17 of an AC tube 14 controlled with the cathode temperature by a tube current controller 15 via a filament transformer 16 to generate X-rays. The winding turn ratio of a step-up transformer is reduced due to two-stage boosting, and the AC tube 14 is miniaturized because the pulse voltage periodically set to 0V is applied.
|
