To provide an X-ray computed tomographic apparatus capable of maintaining a predetermined rotating speed of a rotating frame even when power supply voltage decreases due to X-ray exposure or the like without making the size of the apparatus larger.
A voltage detector 19 detects the voltage of a commercial power supply 14 at an input terminal of a converter 15. When a detected supply voltage VAC is below a voltage Vt, a lead angle determining section 20 determines a lead angle θp for performing lead phase control of a brushless electric motor 10 which drives the rotating frame equipped with an X-ray tube. A phase determining section 21 determines the phase θv of the terminal voltages Vu, Vv and Vw of the brushless electric motor 10 so that current phase in relation to a rotation angle θr equals the lead angle θp.
KURODA MASAHIRO
YOKOYAMA MITSUYUKI
| JP2002000598A | 2002-01-08 | |||
| JP2002359991A | 2002-12-13 | |||
| JP2002136198A | 2002-05-10 | |||
| JPS61143045A | 1986-06-30 | |||
| JP2002078703A | 2002-03-19 | |||
| JP2002218789A | 2002-08-02 | |||
| JPH0191696A | 1989-04-11 | |||
| JPH06197541A | 1994-07-15 | |||
| JP2004097433A | 2004-04-02 |
Kiyoshi Ogawa
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