| 摘要 |
<p>PURPOSE:To reduce the tension change of a magnetic tape due to the change in winding diameter of the tape, by detecting the fluctuation of a magnetic tape tension as an electric fluctuation, comparing it with a reference voltage, and controlling a brake torque. CONSTITUTION:A detection circuit 32 for resistance between tape guide detects a resistance value of the magnetic tape 30 between tape guides 29 and 32 as a voltage and gives an output corresponding to the voltage to a comparison circuit 33, which compares an output (v0) from a reference voltage generating circuit 34 in response to the running mode of the tape 30 with an output (vp) from the circuit 32 and gives the output difference v1 to a power amplifier circuit 35. A motor 36 directly coupled with a supply reel 1 gives the brake torque to the reel 1 at the tape running with an output signal (vm) of the circuit 35.</p> |
