ADC

Discussion in 'The Projects Forum' started by Cerkit, Jan 11, 2009.

  1. Cerkit

    Thread Starter Active Member

    Jan 4, 2009
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    3
    How can I setup an ADC to be a voltmeter and current meter together??
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    282
    It can only convert voltage - you have to use the current through a resistor for the measurement. Current through a resistor makes a voltage across the resistor proportional to the current. A small value resistor will not disturb the circuit too much, and a good quality op amp can make the voltage large enough for the ADC to handle.
     
  3. Cerkit

    Thread Starter Active Member

    Jan 4, 2009
    275
    3
    Ok. So assuming I do that would it would be possible to alternate the input to the ADC depending on whether I want to measure voltage or current. Using a decoder on the input signal for instance??
     
  4. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    You can make it by using a simple SPDT switch.
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    Yes, with an analog switch, or with a microprocessor that has a built-in A to D and multiple switched inputs to it.
     
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