| 摘要 |
<p>PURPOSE:To realize the acceleration control of motor with a simple structure by controlling a motor by the control voltage of a first preparing means and increasing its speed when fast feeding/rewinding is started and switching it to the control voltage of a second preparing means when the speed reaches a prescribed one. CONSTITUTION:When a fat feeding/rewinding mode is indicated, a switching signal 37 is set L, a PWM output 36 is set H and an MC servo circuit 21 is instructed to rotate at low speed. When tape feeding at low speed becomes stable, the PWM output is started and increased gradually. When the output of a comparator 39 becomes H, the output 36 is once lowered, its change quantity is changed and it is increased again. Next, when the comparator 39 becomes H, a change-over switch 44 is turned on and the output 36 is supplied to a drive circuit 22. When the rotation of the motor 14 increases, the comparator 39 becomes H again, a change-over switch 45 is turned on and after that, the motor 14 is driven by the output of a mixing amplifier 35. Thus, the good acceleration control from the start can be performed with the simple structure.</p> |
