| 摘要 |
PURPOSE:To obtain a brushless motor having no torque ripple by reading strainless sine wave information stored in a memory in synchronism with the magnetic field detection signal from a rotor magnet and forming a coil current from the read information. CONSTITUTION:A rotor revolving speed correspondence signal FG from a frequency generator 23 is counted by an address counter in synchronism with a magnetic field by a rotor magnet, sampled value corresponding to the signal repetition number of the generator 23 per revolution of the rotor and the number of sampling relative to the magnetic field from the rotor magnet in two phase coils are stored as digital drive signal waveform information in a memory 21. The information includes one bit for identivying the phase and the residue being the same as the output code of the address counter 22. The read waveform information of the memory 21 is inputted through latch circuits 32, 42 by a timing pulse PFG to the driving circuits 36, 46, and the motor is thus driven. |
