How to build a clamp-on DC ammeter?

Discussion in 'The Projects Forum' started by Jack_K, Jun 28, 2013.

  1. Jack_K

    Thread Starter Active Member

    May 13, 2009
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    I need to measure 50 - 60 amps of DC current. I realize a shunt resistor for a milliamp meter is probably not practical. I have seen clamp-on meters that can measure AC or DC current, but they're rather expensive.

    So, how can I make a clamp-on (or regular) meter to measure high DC current?
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Hall effect sensor/ split iron core then the associated electronics to scale/present a proper calibrated value.. Its not a "simple" task as calibration/hall sensor placement,etc..can be tough for a DIY project.

    But personally I would simply buy a 50mv 100 Amp "shunt" and measure the voltage coming off it with your dc voltmeter. Something like this http://www.mouser.com/ProductDetail...-01099-0/?qs=sGAEpiMZZMukgiigmf73gCjDvzQf9eP1

    100A would be 50mv, 50A would be 25mv.. you can take it from there.
     
  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
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  4. Jack_K

    Thread Starter Active Member

    May 13, 2009
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  5. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    What do you call expensive there are some on Ebay
     
  6. cork_ie

    Member

    Oct 8, 2011
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    If you don't need good accuracy i.e.+/- 10% Blue Point used to make an ammeter suitable for the 50A range you are talking about.
    They had no electronics and solely relied on the deflection of a needle with a magnet attached which was attracted/repelled by the magnetic field generated by the current in the wire.
    Great little too still working almost 35 years later.
    You could easily enough make your own with a cheap magnetic compass and a lot of time to do the calibrations.
     
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