Current measuring

Discussion in 'Embedded Systems and Microcontrollers' started by ifithegr8, Feb 5, 2010.

  1. ifithegr8

    Thread Starter New Member

    Feb 5, 2010
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    I want to measure current ranging from0 - 1 A max i was planing to Try two things 1.make reference of ADC0831 to 1 V and use 1 ohm resistor connected serially to load and measure voltage along it.
    2.Try Digitlizing current flow schematic in datasheet of ADC0831.

    what should i do

    using 89c51 and adc0831
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Is it DC or AC current?

    What is the frequency?
     
  3. ifithegr8

    Thread Starter New Member

    Feb 5, 2010
    7
    0
    its DC but ZTC etc components are not available here
     
  4. t06afre

    AAC Fanatic!

    May 11, 2009
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    1,222
    Post you schematics young man
    This was not a bad base idea. Why did iy work?
     
  5. ifithegr8

    Thread Starter New Member

    Feb 5, 2010
    7
    0
    i think this should work see if i have 1 ohm resistor used.and i should measure voltage across it for current

    1.Make VREF = 1 V
    that will give me 1/256 = 3.9mv resloution i think not bad
    2.In code make equation to convert adc val to voltage as follow

    current = adc_rec_val/256 *Vref;

    am i write?
     
  6. atferrari

    AAC Fanatic!

    Jan 6, 2004
    2,647
    759
    Hear of them but did not suspect their price! Not for an occasional use, really.

    The use of a resistor seems appealing.

    There are cheaper ICs (Maxim or Burr Brown?)

    The OP did not say what is the voltage wrt ground at the point where he wants to measure current. A point of concern...

    There are lot of circuits with inexpensive opamps that could fit.
     
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