| 摘要 |
PURPOSE:To detect the currents of each phase and the polarity of revolving torque by detecting the currents of two phase in three phase by one current detector, preparing currents flowing through each phase while being synchronized with timing driving an inverter switching element on the basis of the detecting signal of a two phase section and feeding back the currents. CONSTITUTION:A current detector 41 generates the current detecting voltage of a two phase section by currents flowing in U and V phase. A detecting- current forming appliance 43 amplifies the current detecting voltage by weighting corresponding to the timing of the voltage, and inputs a feedback signal to a current waveform arithmetic circuit (IC) 44. The IC 44 waveform- operates torque from a speed operational aplifier 17 and a current command signal, by which the speed of rotation reaches a set value arithmetically, and a current control signal, by which the deviation must be controlled in zero, is input to a drive circuit section (DC) 45. The DC 45 converts the deviation into a PWM signal, and turns a switching element making currents flow through U phase from V phase in a switching circuit section 2 ON-OFF together with the timing signal of a timing generating circuit 42. |
