| 摘要 |
PROBLEM TO BE SOLVED: To provide an X ray high-voltage generator comprising a converter, an inverter, a high-voltage transformer, and a rectifier, and securing a stable power factor of the converter even if input AC-power-supply voltage changes. SOLUTION: In the converter 3, two of a half bridge converter 30 and an asymmetric half-controlled bridge converter 31 are connected in parallel. Although the half bridge converter 30 has a good power factor and is stable, the power factor decreases when the input AC-power-supply voltage becomes large. A mixed bridge converter 31 has a harmonic content near a zero crossing point, accordingly, its power factor is slightly lower than that of the half bridge converter 30, however, the power factor does not decrease even when the input AC-power-supply voltage becomes large. So, it is changed to the half bridge converter 30 by an AC input below a reference value voltage. It shall be changed to the mixed bridge converter 31 by the ac input larger than reference value voltage. COPYRIGHT: (C)2005,JPO&NCIPI
|
