| 摘要 |
PURPOSE:To save input to an induction motor by comparing the number of anode rotation with reference frequency and controlling in an optimum condition input frequency to an induction motor according to output from a comparator. CONSTITUTION:Vibration caused by rotation of an anode of X-ray tube 2 is detected with a rotation detector 4 comprising a piezoelectric device, and converted to voltage signal corresponding to frequency component of signal with a frequency-voltage converter 7. The signal voltage is compared with reference voltage sent from a reference voltage generator 9 with a voltage comparator 8, and voltage corresponding to difference between the rotating number and the setting rotating number is outputted as differential voltage. This voltage is added to reference voltage of the reference voltage generator 9 with an adder 9' and again converted to frequency signal with a frequency converter 10. Thereby, an anode of X-ray tube 2 is driven at high frequency. |
