Drive circuit for 2-phase sinusoidal drive brushless motor

Abstract

Abstract PURPOSE:To obtain an accurate rotating speed control by respectively supplying 2-phase stator coil driving voltages through a low pass filter to two square calculating means, and controlling the Hall element driving current based on the addition signal outputs of both calculating means. CONSTITUTION:Stator coils L1, L2 respectively receive energization control by power amplifiers 23, 24 which input 2-phase AC signals of pi/2 phase difference from Hall elements H1, H2 through operational amplifiers 21, 22. The output voltages of the amplifires 23, 24 are respectively inputted through low pass filters 26, 27 which are composed of a resistor R6 and condensers C to square calculating units 28, 29, and are added via a resistor R7. Then, the added output e0 becomes a DC voltage which does not include a ripple component. The superposed voltage of the output voltage e0 and a DC power source E is supplied to an operational amplifier 20. Since the peak value of the AC voltage supplied to the units 28, 29 becomes large at the low speed time, the output of the amplifier 20 is increased, and the drive current of the Hall elements is increased. The operation becomes reverse to the above operation as compared with the reference speed at the high speed time.

Inventors

• 👤 Toshiaki Nakasuji
• 👤 中筋　敏明

Bibliographic Details