From an F-V converter i have got voltage values.. i.e for f(hz)-v(v) 65hz - 5v . . . . . 100hz-9.85v. my next stage is feeding these output from f-v converter to an device (opamp\comparater) so tat i get an constant output 0f 5v for frequencies above 65hz, and for frequencies from 0-64hz it should provide 0v. so please suggest me ideas about tis.