| 摘要 |
<p>PURPOSE:To quickly stop the reel motor of a tape take-up device without allowing a tape to slacken when the power supply is discontinued. CONSTITUTION:When power supply is made, a controlled object changeover switch 8 sets one of DC motors 41 and 42 to a driving state in accordance with the transferring direction of a tape 1. When the tape 1 is fast-fed in the forwarding direction (or reverse direction), the DC motor 41 (or 42) takes up the tape 1 by means of a motor drive circuit 5. When the power supply is discontinued, the DC motor 42 (or 41) on the feeding side is set to a short- circuiting state through a current limit circuit 6, since the circuit 5 loses its driving ability and a power discontinuation detecting switch 7 is set to a connected state. Since an electromagnetic braking force is generated in the motor 42, (or 41), the motors 41 and 42 quickly stop while tension is applied to the tape 1.</p> |
