| 摘要 |
PURPOSE:To eliminate information of rotary direction, and to simplify a circuit by obtaining a current feedback signal by separately detecting the current feedback signal as information of absolute value and two types of polarities, and combining them. CONSTITUTION:A controller for controlling the current of a synchronous motor is composed of a current absolute value detector 61, a current polarity discriminator 62, an inverting amplifier 63, and a switch 64. The detector 61 detects the amplitudes of phase currents, and the discriminator 62 detects the polarity of the phase current. The switch 64 selects the amplifier 63 in response to the polarity, combines information of absolute value and two types of the polarities thereby to form a feedback signal if. |
