| 摘要 |
<p>PURPOSE:To facilitate the control of tension of a magnetic tape under travelling, by using one of the two capstans for control to make the speed constant, and the other for control of the tension of the magnetic tape. CONSTITUTION:A constant voltage power supply 21 which decides the reference revolving torque of a capstan motor 5B and the voltage corresponding to the tension of a magnetic tape 3 and generated from a deteting mechanism 17A are fed to an adder circuit 22. A driving circuit 23 of the motor B is provided, and pinch rollers 7A and 7B, an erasing head 2A2, a recording head 2B, a reproducing head 2C and a tension arm 12A move backward with the output of the circuit 22. The voltage of the power supply 21 is set so that the number of revolutions of the motor 5B is reduced in the rate of several % compared with a capstan motor 5A which is controlled at a constant speed when the tape tension detected by the mechanism 17A is set at 0.</p> |
