| 摘要 |
PROBLEM TO BE SOLVED: To accurately control to position in a low-speed range and to rapidly rotate with low noise by exciting a coil by a first exciting system, exciting by a second exciting system, and exciting by one of the exciting systems in response to a rotating speed of a rotor. SOLUTION: At the time of a motor starting and rotating a motor at a low speed with low rotating speed of a rotor, a switching signal is not input to a switching logic circuit 9. The circuit 9 selects signals (a) to (f) from a sequence control circuit 3, and output to a three-phase bridge circuit 2. Arm circuits 2a to 2c are switched according to the signals (a) to (f) generated by the circuit 3, three-phase alternating currents flow to motor coils 1, and the motor is rotatably driven. When rotation of the rotor becomes high speed, the switching signal is input to the circuit 9, which selects signals a' to f' from a sensorless commutating circuit 8, and switches the circuit to output to the circuit 2. |
