| 摘要 |
<p>PURPOSE:To freely set tape speed by providing a means to drive one side reel with the output signal of an adder and a period central value setting means setting a converting action point to an output value to the period of the input signal of a period detecting circuit. CONSTITUTION:The sum of the output of latches 14A and 14B is made by an adder 5, converted into an analog voltage by a D/A converter 8, inputted to a driving circuit 6 and the driving circuit 6 is constituted so as to conduct the current in proportion to the difference between the output voltage of the D/A converter 8 and the suitable reference voltage. Finally, for a feeding-back loop, the output of the adder 5 is stabilized to a certain constant value. At control circuit in which the sum of the period of a pulse outputted by FG3A and 3B provided at reels 2A and 2B is constant, a magnetic tape 1 is travelled approximately at constant speed. When the presetting value of counters 13A and 13B is changed by a period central value setting means 9, the number of the clock to count the counters 13A and 13B is changed and the speed of the magnetic tape 1 is changed in accordance with it. Thus, the tape speed when the data on the tape are read can be set in detail.</p> |
