| 摘要 |
PURPOSE:To improve the speed stability of the motor with a simple configuration by positively feeding back a part of an operation signal to apply it to a preset reference signal to form a new comparison reference signal and adding a speed signal thereto. CONSTITUTION:The rotating speed of the motor 4 is detected by a speed detector 6, and a speed voltage is negatively fed back to an addition point 10. The operating amount of an electric power control element 3 caused by a firing circuit 2 is detected by an operating amount detector 7, and the operating amount detecting voltage is positively fed back to an addition point 9. The reference voltage is added with the operating amount detecting voltage at the addition point 9 to form the comparison reference voltage becoming new reference voltage, which is further added with the speed voltage at the addition point 10 to obtain a deviation. This deviation is inputted to the firing circuit 2, which controls the phase of the conduction angle of an electric power control element in response to the deviation to automatically control the rotating speed of the motor 4. |
