Optoisolator

Discussion in 'General Electronics Chat' started by rufus1907, Oct 27, 2008.

  1. rufus1907

    Thread Starter Member

    Aug 7, 2008
    10
    0
    Is it possible to transfer a low amplitude DC signal from the input to output by using an Optoisolator? I mean, Is the output a function of the input or a switching signal according to input? If yes what kind of Optoisolator can I use to isolate my low amplitude DC signal?
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Optoisolators can be considered analog devices, thus the output is a function of the input. There are many in the market, if you make a search in google you will find many and you have to choose one depending on your needs.
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Optoisolators are mainly for digital data. The IRLED wants 30 - 50 ma to drive, and the output is usually an open collector phototransistor or logic compatible.

    Could you give some data - how low is low amplitude, and why it needs isolation?
     
  4. John Luciani

    Active Member

    Apr 3, 2007
    477
    0
    It depends on the levels. A linear optocoupler, like the Vishay IL300, may work.

    You may be better off looking for isolation amplifiers. Checkout TI and Analog Devices.

    (* jcl *)
     
  5. rufus1907

    Thread Starter Member

    Aug 7, 2008
    10
    0
    it should be isolated because the signal have high potential according to ground and I need to measure this mV Dc signal. I already checked isolation amplifiers but for example iso122 and iso124, it is really hard find them in europe all of the stocks are ran out. What I can easy find is, HCPL optoisolator at the moment.
     
  6. John Luciani

    Active Member

    Apr 3, 2007
    477
    0
    IIRC the HCPL are digital devices.

    Measuring a mV signal through a linear optocoupler will be difficult.
    A pre-amp + IL300 could work.

    A pre-amp + A/D converter on the signal side would work. Use the optocoupler
    on the A/D digital lines.

    (* jcl *)
     
Loading...