333mV AC to 0-5Vdc

Discussion in 'General Electronics Chat' started by Liaquat, Sep 20, 2010.

  1. Liaquat

    Thread Starter New Member

    Sep 20, 2010
    Anybody have idea about the Circuit to convert 0-333mV Ac to 0-5 V dc.
    We have CTs (Current Transformers) which are converting 0-50 Amp to 0-333mV.I need Circuit which can convert 0-333mV signal to 0-5 V dc or 4-20mA,so that I can use it with Data Logger.Thanks.
  2. tom66

    Senior Member

    May 9, 2009
    Since you're using it with a data logger then you won't need much output current.

    You should probably use an op-amp full wave rectifier and amplify the output. Then you might want to average it to get a reading for the datalogger.
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    Have you tried a quick search on Google? If think you should start in that end. Then you have done some reading you can come back with questions.
    Last edited: Sep 20, 2010
  4. russ_hensel

    Well-Known Member

    Jan 11, 2009
    This is a good job for an op amp, and there are probably special circuits for the current loop ( but you can use op amps for that too ).
  5. Liaquat

    Thread Starter New Member

    Sep 20, 2010
    I tried to make some circuit but not succeed can anybody send circuit layout where 333mV AC can be converted to 0-5 Vdc.Thanks.
  6. SgtWookie


    Jul 17, 2007
    See the attached; it's a modification of a design that was in the magazine EDN.

    I'm not real keen on it because the input goes below ground. However, if you used a dual rail supply (at least 6v on each rail) then it would be OK.
    Interesting; it doesn't work if you use a negative rail.
    The output waveform has some distortion because the input signal is partially clamped to ground via U1a's input ESD protection diodes.

    The opamp used has rail-to-rail inputs and outputs.
    Last edited: Oct 11, 2010