| 摘要 |
PURPOSE:To stop a commutatorless motor by stopping the operation of a drive circuit when the frequency of a counterelectromotive voltage generated in an armature winding becomes higher than the certain frequency, thereby effectively detecting the locking state. CONSTITUTION:A counterelectromotive voltage detector 6 detects the relative position of a magnet rotor 5 by the counterelectromotive voltage generated by the armature winding 4 of a commutatorless DC motor 3. A drive circuit 7 drives semiconductor switching elements S1-S6 of a semiconductor commutator 22 by the output of the detector 6. A frequency detector 11 detects the frequency of the output of the detector 5, and stops the operation of the circuit 7 when the detected frequency becomes higher than the certain frequency. |
