want help to raise earth resistivity tester to 50 volt instead of 5 v

Discussion in 'General Electronics Chat' started by mabdulraheman, Nov 18, 2013.

  1. mabdulraheman

    Thread Starter New Member

    Nov 18, 2013
    can any one help me to raise earth resistivity tester circuit voltage to 50 volt

    I am talking about the voltage used to measure earth resistivity not the circuit voltage ...


    I can use a 50 dc volt external power source but the problem when the micro

    controller measure the received voltage .... it cannot exceed 5 volt ..

    so If I used a 10 mega resistor to drop 50 v to 5 v and 40 v to 4 and so on ...

    is this works fine ?? or will cause to get unreal earth resistivity values when use it ??
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    If your micro wont read 50V, then why are you increasing it to 50V, the circuit you posted is a Differential amp with variable gain, not the power supply?
  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Using a voltage divider resistor pair could help but we would need to learn more about your power supply and what the various connections in the differential amp are supposed to do.