| 摘要 |
<p>PURPOSE:To prevent the fluctuation of tension of a magnetic tape caused by a variance of a friction torque of a motor by measuring the friction torque of a reel motor. CONSTITUTION:A reel motor control circuit 10 controls reel motor driving circuits 8, 9 and increases a current applied to reel motors 4, 5 at a time interval which has been determined in advance until a pulse is generated from reel tachometers 6, 7, and measures a friction torque of two reel motors 4, 5. Subsequently, from this friction torque, a motor current value is calculated, and tension of a magnetic tape 1 is adjusted. In such a way, the fluctuation of tension applied to the magnetic tape 1 caused by a variance of the friction torque of the reel motors 4, 5 can be prevented.</p> |
