| 摘要 |
PURPOSE:To prevent a motor against the destruction of parts, by detecting whether the motor is rotating by external force and whether it is generating the current, and by connecting armature winding to a motor drive circuit only when the current is smaller than a definite value. CONSTITUTION:In a brushless DC motor, the position of a rotor 1 is detected with a phase detection device 2, by which position signal the current direction to cause the current to flow from a DC power source 5 to a stator armature winding 4 with a motor drive control device 13 is changed over by driving a transistor 6 to rotate the rotor 1. A relay 11 is provided for the changeover means to change over the armature winding 4 from a motor drive circuit 8 to a resistance 12 to connect. This relay 11 is excited with the abovementioned control device 13 and connects the armature winding 4 to the motor drive circuit 8. The winding current is detected by a current detection device 14. In case the detected current value is larger than the set current value, a current value processing device 16 is provided to output the current large signal to the control device 13. The destruction of semiconductor parts by the short-circuit current is thereby prevented. |
