| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a single-phase brushless DC motor drive circuit capable of performing a secure start not only in normal rotation but also in reverse rotation. <P>SOLUTION: A magnetic sensor 7 is disposed at a near zero advance angle, the center between teeth 4a, 4b, and a magnetic sensor 8 has a predetermined advance angle in the motor normal rotation direction further than the position of the magnetic sensor 7. When the normal rotation is started, a selection circuit 12 selectively outputs the magnetic pole position detection signal of the magnetic sensor 8, and a control circuit 14 controls a switching circuit 13 to start the DC motor so that the teeth 4a, 4b are directed in the conducting direction of the motor coil 6 relative to the magnetic pole of a magnet rotor 2 to generate repulsion. When the reverse rotation is started, the selection circuit 12 selectively outputs the position detection signal of the magnetic sensor 7, and the control circuit 14 controls the switching circuit 13 and starts the DC motor so that the teeth 4a, 4b are directed in the conducting direction of the motor coil 6 relative to the magnetic pole of the magnet rotor 2 to generate an attraction force. <P>COPYRIGHT: (C)2010,JPO&INPIT |
