| 摘要 |
PURPOSE:To obtain a speed control with high accuracy by a method wherein an output frequency of an a.c. generator which is rotated together with a d.c. motor is detected and a control signal voltage generated in accordance with the detected frequency is utilized. CONSTITUTION:As a rotational speed of a motor 1 varies, an output frequency of a generator 2 which is rotated together with is varies. By this change of pulse width of output pulse of a pulse converter circuit 3 varies, and a pulse spacing of output pulse of monostable multivibrator 4 varies, and an output voltage of a voltage convertor circuit 5 varies. This output voltage is led to an input terminal of a motor driving circuit 7 through a filter circuit 6, and a rotational speed of the motor 1 is maintained constant. |
