PURPOSE: To prevent any overcurrent of an inverter circuit and stop the operation of an inverter when overvoltage is applied to an X-ray tube by temporarily charging the operational frequency of the inverter when the detection value of the current of the inverter exceeds a preset value.
CONSTITUTION: A single-phase a.c. power source 8 is connected to a switching circuit 9. A d.c. power source is supplied to an inverter 2 through a smoothing circuit 18. The input voltage of the inverter 2 is set by a circuit 9 controlled by a gate-controlling circuit 12 having as inputs both a signal corresponding to an actual value of the input voltage of the inverter 2 sent from a voltage divider 19 and a tube-voltage setting signal. The inverter 2 is put to work by an X-ray exposure signal fed to the input of an inverter-frequency controlling circuit 15, and an X-ray tube 6 is put to work through a high-voltage transformer 3 and a rectifier 4. A detector 13 detects the current of the inverter 2. When the detection value of the detector 13 exceeds a preset value, the circuit 15 temporarily changes the operational frequency of the inverter 2 through a comparator 14. In addition, the overvoltage signal of the X-ray tube 6 stops the operation of the inverter 2 through a comparator 17, thereby enabling stable control to be performed.
| WO/2023/117733 | OPERATING A FILAMENT OF AN X-RAY TUBE |
| WO/1992/012613 | DYNAMIC PULSE CONTROL FOR FLUOROSCOPY |
| WO/1988/000789 | X-RAY INSTALLATION FOR X-RAY DIAGNOSTIC AND/OR TREATMENT |
TOKUNAGA KIICHI
AMANO HISAO
HINO HIROBUMI
UEMURA HIDEKI
HITACHI MEDICAL CORP