| 摘要 |
PURPOSE:To detect an overspeeding with accuracy, in a rotor excessive speeding detecting device for a centrifugal machine, etc., by comparing a rotating signal with a reference frequency signal which is switched being linked with change-over of rotor's r.p.m. CONSTITUTION:When a rotor 1 of a centrifugal machine, etc. rotates, a rotating signal of a frequency which corresponds to the rotation is obtained by an optical adapter 2 and a rotation detector 9. On the other hand, emission signals of oscillators 10 and 11 which emit respectively different reference frequency signals are compared with the aforementioned signal by a frequency comparator 13, and in case if the rotor's r.p.m. proved to be larger than frequency of the reference frequency signal, it is determined to be an overspeeding and the rotor is decelerated by a control circuit 14. 12 is a switch for changing outputs of the oscillators 10 and 11, and since this switch is linked with a speed setting dial of the rotor and it is so designed that a reference frequency signal corresponding to the maximum tolerable r.p.m. of the rotor is put into the comparator, it is possible to detect an overspeeding with accuracy. |
