X-RAY CONTROLLER

PURPOSE:To permit continuous setting of bulb current value by feeding an adjusting voltage obtained by a bulb current setting means into a filament current caluclating means and a space charge correcting means and applying the difference of outputs into the filament of an X-ray tube. CONSTITUTION:The voltage DELTAV which varies in triangular wave form is obtained by transmitting the signal S1 of a bulb current selecting switch 10 into an adjusting voltage generating circuit 11. The filament current at a standard bulb voltage is calculated by setting S1 and DELTAV into a filament current calculating circuit 12, and the space charge correcting value is obtained by setting S1, DELTAV, standard bulb voltage, and set bulb voltage into a space charge correcting circuit 13. The difference of the both outputs is obtained from a differential amplifier 14, and thus the filament heating current for an X-ray tube 9 is formed. Accordingly, the adjusting voltage can be calculated automatically only by setting a desired bulb current value, and a switching signal can be formed, and the bulb current can be varied continuously and easily.