Advise neede about amplification of the signal

Discussion in 'General Electronics Chat' started by jcp, Jan 8, 2013.

  1. jcp

    Thread Starter New Member

    Apr 12, 2011
    Hello Friends;
    I have a Flow meter which installed on the gas line.

    Problem is that i connect it to the GE PLC 90-30 series high speed counter module to read the frequency crossponding to the flow.

    But the voltage amplitude is too low to unable to read the values.

    Now it gives me 315 Hz at 300 mV.
    Please help me how i just amplify the voltage without disturbing the frequency.

    There are two wires come out from the flow meter. I see that signal on the oscillscope almost between sine and square wave shape.

    Please help me how i build the circuit to amplify the voltage from 300 mV to 4 to 5 V.

    Thanking you i will remain

  2. bertus


    Apr 5, 2008

    Does the 300 mV AC have a DC offset?

    You could make a comparator with a reference of about the middle of the 300 mV signal.
    On the output of the comparator, you can put a resistor of about 1K to +5Volts.