| 摘要 |
PURPOSE:To readily detect the timing of commutation of a brushless motor by utilizing the output of an encoder by selecting the number of light transmitting lits at a code plate used in the encoder equal to the number of poles of the motor to be driven. CONSTITUTION:The output of an encoder 12 for detecting the movement of a code plate provided with light transmitting slits by an image sensor having a basic pitch equal to the arranging pitch of the slits is input to a phase counter 13, and its counted output is supplied to a function generator 14. The generator 14 generates a sinusoidal signal in response to the counted output to control the commutation of an exciting current in a pulse motor 11. The number of the slits in the code plate used in the encoder 12 is selected to be equal to the number of poles of the motor 11 to be driven to bring the variation in the phase shifting amount obtained upon rotation of the plate into coincidence with the variation in the rotating angle in a rotor. |
