| 摘要 |
<p>An apparatus for performing industrial X-rays photographs comprising a DC voltage source (PS) connected to the primary winding of a high voltage transformer (AT) through a switch or chopper (SW1) with variable durations of the opening (time-off) and the closing (time-on) intervals, periodically controlled by control means (UC), and an X-ray tube (RG) fed through the secondary winding (S1-S2) of the high voltage transformer (AT). According to the invention, the high voltage transformer (AT) comprises an additional sensing winding (MS) connected to a comparator (CP1) having the other input connected to a first reference voltage adjustable for setting a desired value of the high voltage applied to the X-ray tube (RG). A differential amplifier (CP2) having inputs connected to the return of the milliAmperes and to a second reference voltage, respectively, is connected through a voltage/frequency converter to the set input (S) of a resettable multivibrator (MV) the output of which drives the switch (SW1). <IMAGE></p> |
