| 摘要 |
PURPOSE:To avoid the troublesome procedure of converting the rotating direction in a system frequenctly operating reversible rotation by determining the rotating direction only according to the output voltage direction of a speed setting potentiometer. CONSTITUTION:A speed setting potentiometer 1 produces its output of polarity corresponding to the rotating direction of a motor 1 as a rotating speed setting value. A rectifying and smoothing circuit 4 rectifies and smooths the output voltage of a polyphase AC tachometer generator 3, and a phase rotation detector circuit 7 detects the phase rotating direction of the output voltage from the generator 3. A multiplier 8 multiplies the output voltage from the circuit 4 by the output of the circuit 7 to thereby detect the magnitude and rotating direction of the motor 2. A controller 5 control the rotating speed of the motor 2 in response to the deviation between the output voltage from the potentiometer 1 and the output voltage from the multiplier 8. |
