| 摘要 |
<p>PURPOSE:To always hold the dynamic range of a speed control circuit to the maximum limit by changing the fixed output level of a phase control circuit and controlling the output level of the set value or above of the speed control circuit. CONSTITUTION:The change of the output of a PWM counter 14 accompanying the change of the preset value to occur by a preset value generating circuit 5 of a speed control circuit 1 is supervised by a duty discriminating circuit 15, and when the result is the set value or above, a changing prohibiting output is outputted to the circuit 5. The information is inputted to a fixed output preset value generating circuit 16, a preset value is changed, the output level of a phase control circuit 2 is changed, the output of the speed control circuit 1 and the output of the phase control circuit 2 are added, the digital speed error is changed by the change of the rotational speed of a driving drum motor, and the output level of the speed control circuit 1 is controlled so as to put into the value set beforehand.</p> |
