| 摘要 |
PURPOSE:To obtain an inverter-type X-ray device with which a set tube voltage level can be accurately produced by sampling the maximum level for each pulsation and performing feed back control according to this maximum level. CONSTITUTION:During X-ray irradiation, signals (INV1) and (INV2) are delivered from an inerter controller 31 to an inverter 4 and a sample hold controller 32. The signals (INV1) and (INV2) operate alternately with a frequency of f2. In the controller 32, a NOR circuit 41 delivers an inverted OR (INV)' and a differentiating circuit 42 delivers a pulse (SH) to a sample holder 33 during the rising of the inverted OR (INV)'. The pulse (SH) is delivered during the rising of the signals (INV1) and (INV2) or the end of each switching operation. The maximum level of tube voltage (Vx) is generally produced immediately after the end of each switching operation. Therefore, when the sample holder 33 holds the pulse (SH) representing tube voltage (Vx'), the output (Vxp') of the sample holder 33 becomes almost equal to the peak level of tube voltage. Since an error amplifier 10 controls a DC-DC converter 3 through a DC-DC conversion amplifier 11 according to the difference between (Vxp') and (Vset), a set tube voltage peak level can be achieved regardless of the amplitude of the pulsation for 2f2 of tube voltage.
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