non common ground buffer

Discussion in 'General Electronics Chat' started by gehan_s, Nov 10, 2012.

  1. gehan_s

    Thread Starter Active Member

    Sep 17, 2012
    hey all,

    i want to buffer a voltage between 2 DC circuits with different grounds. a traditional op amp buffer won't work as i am not prepared to connect the 2 grounds together. what i would want is something like an optocoupler but with linear characteristics. can anyone suggest a method for doing this ????? (the voltage that i want to buffer is in the range of 0V to 5V. the buffered voltage will actually be an analog input to a PIC).

    thanks in advance !!!!!!!!!!!
  2. ScottWang


    Aug 23, 2012
    Here is what I'm thinking about:
    DC circuit 1 → V to F → Op Amp → optocoupler → F to V → Op Amp → PIC ADC port
    DC circuit 2 → V to F → Op Amp → optocoupler → F to V → Op Amp → PIC ADC port

    V to F - maybe 0~5V convert to 0~5Khz.
    F to V - maybe 0~5Khz convert to 0~5V
    Op Amp - Op Amp maybe is unnecessary, it depends on the final design.
    Last edited: Nov 11, 2012
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    Last edited: Nov 11, 2012