| 摘要 |
PURPOSE:To suppress fluctuation of generated torque by switching the level of each current control reference signal to be inputted to each comparator in two stage. CONSTITUTION:A switching signal generating means 30 generates number of exciting phase switching signal CNT1 or CNT2 depending on single-phase excitation or two-phase simultaneous excitation thus causing a level switching means 30 to switch the level of current control reference signals Vref.ac, Vref.bd being fed to comparators 12, 14. Consequently, each phase coil current can be switched between high current (100% current, for example) for single-phase excitation and low current (71% rated current, for example) for two-phase simultaneous excitation. This constitution suppresses fluctuation of torque while keeping the step angle as it is by automatically switching each coil current depending on the number of exciting phases. |
