| 摘要 |
PURPOSE:To reduce the torque ripple of the brushless motor by a method wherein a sine wave information stored in the memory is read out by means of the signal synchronized with the rotor revolution to form the stator coil current. CONSTITUTION:The signal FG which is obtained from the frequency generator 22 and is in response to the rotor revolution speed, is put into the counters 25, 26 as the pulse PFG through the amplifier 23 and the Schumit trigger circuit 24. In ROM 20, 21 a waveform information, which possesses the mutually 90 deg. different phases and are put in sampling based on the tooth number of the frequency generator 22, is stored. The counters 25, 26 designate the address of ROM 20, 21, and receive the signal CS4 obtained from the detected signal of the hole element 32 through the flip-flop circuits 34, 35 to read out the information of ROM 20, 21. The output information is provided to the coils 4, 5 by means of the D/A converters 27, 28, the amplifiers 29, 30 and the drive circuits 31, 32. |
