| 摘要 |
PURPOSE:To eliminate the position detecting element of a rotor by producing energization mode signals on the basis of the outputs of bridge circuits formed in the armature coils of the respective phases, thereby controlling a current supply circuit. CONSTITUTION:Bridge circuits 4-6 for detecting induced voltages of high band correcting reactance element C2 are formed in armature coils 1-3 of the phases of a brushless DC motor. The induced voltages detected by the bridge circuits 4-6 are compared with comparators 13-15, an energization mode signal for sequentially switching the energization modes for energizing the coils 1-3 by a 3-phase logic circuit 22 is produced on the basis of the compared result. Switching transistors 32-37 for energizing the coils 1-3 are switched by the mode signal. |
