| 摘要 |
PURPOSE:To smoothly rotate an induction motor by enable to apply the sinusoidal AC voltage of an arbitrary voltage level having less waveform distortion to the motor. CONSTITUTION:A current flowed to an induction motor IM is detected by a current detector CS, sampled at the prescribed timing by a current detector CD to form a motor current detection signal. This motor current detection signal is fed back to a control signal generator CO to control the effective value level of 3-phase sinusoidal AC voltage to that a motor current becomes the prescribed value. The generator CO generates a switching control signal for applying 3-phase sinusoidal AC voltage to the motor IM. A drive circuit DO forms a drive signal of transistors Q1, A2 on the basis of a switching control signal output from the generator CO. |
