| 摘要 |
PURPOSE:To sustain best conversion characteristics of resolver by connecting a control means comprising a voltage controlled oscillator and a PWM circuit to the post-stage of the resolver for a two-phase DC brushless motor thereby controlling a chopper circuit. CONSTITUTION:Carrier 1 having predetermined amplitude and frequency is fed to a resolver 2 coupled with a DC brushless motor 7 in order to determine amplitude modulation characteristics corresponding to the rotation of a motor 7. Thus determined amplitude modulation characteristics are then demodulated to obtain a rotation signal component of the motor 7. The demodulated wave is then fed to a voltage controlled oscillator VCO 4 in order to determine a frequency modulated signal having frequency variable according to the rotational position of the motor 7. Outputs from the VCO 4 and a control signal input terminal 8 are then subjected to PWM modulation through a PWM modulation circuit 5 which produces an output for controlling a chopper 6 and driving the motor 7. Consequently, best modulation characteristics of resolver can be sustained. |
