| 摘要 |
<p>PURPOSE:To control a capstan motor at the accurate speed corresponding to command frequency by comparing the command frequency with the rotation frequency of a capstan motor directly, and controlling the output of the motor by a comparative output. CONSTITUTION:A detection signal from the rotation detector 2 of a capstan motor 1 is inputted to the subtraction input terminal D of a counter 8 through a frequency convertor 10, and a command signal is inputted to the addition input terminal U through a frequency convertor 9. When the motor 1 rotates at a speed corresponding to command frequency, the frequencies of convertors 9, 10 coincide with each other, and the differential output of the counter 8 becomes 0. However, if there is an error such as variation of load etc., the deviation is caused in the outputs frequency of convertors 9, 10, and the error voltage is supplied to an adder 7, and the deviation of rotation speed of the motor 1 is corrected. Thus, the motor can be controlled accurately corresponding to the command frequency.</p> |
