| 摘要 |
PROBLEM TO BE SOLVED: To reduce generation of the spike voltage, by providing a smoothing capacitor and a power supply conductor connected to a power supply in parallel, and connecting a plurality of switching circuits to feed each of a plurality of electric coils to a plurality of branched conductors. SOLUTION: Three smoothing capacitors 5-7 are arranged on a substrate 1 in (x) direction with equal pitch, and a capacitor 6 is arranged at the center in the (x) direction of a switching unit 3. A power supply bus bar 8 is connected to three smoothing capacitors 5-7. The positive voltage and the negative voltage of a DC power source are applied to a terminal 8Ap and a terminal 8Bp, respectively. The each relative positional relationship of each combination of the smoothing capacitors 5-7 with the switching units 2-4 is approximately the same, and the shape of branches 8Ab-8Ad, 8Bb-8Bd is identical. Because the relative position to the switching units 2-4 is substantially the same, the inductance of the smoothing capacitors 5-7 is close to the inductance of power supply conductors of the switching circuits 2-4, and the variation in each phase can be eliminated. |
