Current sensing hardware

Discussion in 'General Electronics Chat' started by poopscoop, Dec 25, 2014.

  1. poopscoop

    Thread Starter Member

    Dec 12, 2012
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    I need to detect up to 50 amps of DC current from a 12v battery to a trolling motor with a microcontroller.

    Most hall effect sensors I'm finding that are packaged for direct micro interface are < 20A, and the larger ones lack a clamping action (I believe the term is 'split core').

    Is there a better way to search for a high current transducer? Is there an easy way to buy just the hall effect IC and build a clamp for it?
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,050
    3,244
    Why not use a 50A resistive shunt?
     
  3. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    google : copper shunt resistor.
     
  4. poopscoop

    Thread Starter Member

    Dec 12, 2012
    139
    16
    I considered a shunt, but my micro ADC has only 10 bits of precision, so detecting a range of currents from1 - 50 amps reliably would require more voltage drop and more wasted power.
     
  5. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    You can using the op amp to amplifying the voltage.
     
  6. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    I've used these in a few current sensing projects to measure solar panel current. Direct interface with a 5vdc controller but your 10bit resolution might be a problem unless you over-sample and software filter the input as you have about 4.88mv per ADC step and the output of a 50A sensor is 23mv per amp.

    http://amploc.com/amploc.com/AMPLOC.html
    http://ampsense.com/HANDBOOK web.pdf
     
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