| 摘要 |
<p>PURPOSE:To stably travel a magnetic tape even in the transient condition to change from a standard travelling speed to a fast travelling speed. CONSTITUTION:The control voltage outputted by a controller 15 is inputted to a driver 9 through a switch 18 and a motor 10 is driven. Thus, a take-up reel 3 is rotated and a magnetic tape 20 is wound. An FG 13 generates a pulse synchronized with the rotation of the motor 10 and the pulse is detected by a Hall element 14. The controller 15 loads a servo so that the interval between the detecting pulses can be coincident with the prescribed reference value. A controller 8 measures the interval between the output pulses of pulse generators 4 and 5 and outputs the control voltage corresponding to the error between the measured value and the reference value. A comparator 17 compares the control voltage outputted by controllers 8 and 15 and switches the switch 18 in correspondence to the compared result.</p> |
