| 摘要 |
PROBLEM TO BE SOLVED: To suppress lowering of torque as much as possible at the time of switching the phase by providing an auxiliary phase selection means for delivering a current error signal from the differential unit for each coil, as a current command, to other coil while switching selectively. SOLUTION: When a command is delivered from a servo controller 8 and a digital signal for making a switching from contact (c) to contact (a) is delivered from a phase switching controller 9 to the switch 13 for a coil 2, a stepwise command 2 is applied to the coil 2. But the output of a power operational amplifier 20 is saturated and the current 2 flowing into the coil 2 can not follow up the stepwise command. When an output current is subtracted from the current command value for the coil 2 and the difference is connected with (b) contact of the switch 13 for a coil 1, and a digital signal for making a switching from contact (a) to contact (b) of the switch 13 for coil 1 is delivered from a phase switching controller 9, a command 1 having smoothed step is delivered to the coil 1 and the motor current is prevented from lowering at the time of switching. |
