| 摘要 |
<p>PURPOSE:To control a tape tension between a take-up reel and a capstan in a constant value at playing, by performing voltage control for a reel motor so that number of revolutions N versus torque characteristic T is approximated to a curve of NT=constant with the tape tension as a parameter. CONSTITUTION:A motor is directly coupled with a take-up reel and the reel is driven without slip with the motor. The characteristic of the number of revolutions of reel N versus a driving torque T with a tape tension set at a desired constant value, is obtained by taking a voltage V as a parameter, and the motor application voltage to various characteristics L1, L2... is written in a memory by taking the number of revolutions N as an address. At playing, the voltage is read out according to the acutually measured number of revolutions N, and D/A-converted and applied to the motor.</p> |
