| 摘要 |
PURPOSE:To allow a brushless motor to delay rotating speed without recourse to open-phase operation and to ensure the motor to restart by providing timer circuits to stop the drive for a specified time at the beginning of each winding driving period corresponding to the output of a pulse detection element. CONSTITUTION:A brushless motor is equipped with stator windings 2a and 2b, a pole detection element 3 composed of a Hall element, etc., to detect the position of poles of a permanent magnet rotor, a drive control circuit 10 to set the terminals of OUT1 and OUT2 alternately Hi and Lo in accordance with the output of the pole detection element 3, etc. Particularly, timer circuits 13a and 13b are provided to stop the drive for a specified time at the beginning of each winding driving period in compliance with the output of the pole detection element 3. With these timer circuits 13a and 13b the drive of winding is stopped for a specified time in each driving period. The rotating speed can thereby be delayed without recourse to open-phase operation and without special starting compensation circuit the motor can surely be restarted when unlocked. |
