Simple shunt resistor

Discussion in 'General Electronics Chat' started by cczone, Jan 6, 2009.

  1. cczone

    Thread Starter Member

    Dec 17, 2008
    Well, I am trying to make a simple shunt resistor of 1 mili ohm on my own.
    I searched from the internet, the easiest way will be using 10 AWG copper wire over 1 feet.
    Any other suggestion? haha ...
  2. hgmjr

    Retired Moderator

    Jan 28, 2005
    If accuracy is at all critical then purchasing a resistor of this value will be much more likely to get you the value you need.

    Measuring a milliohm so that you can tell when you have got it right will be an interesing challenge.

    I expect you will apply a known voltage to the resistor and then check that the proper current is established. This will bring into play the accuracy of the meter with which you make the measurement.

  3. AchMED

    Active Member

    Aug 5, 2008
  4. KL7AJ

    AAC Fanatic!

    Nov 4, 2008

    When I worked at HIPAS observatory, we had to build our own precision meter shunts...which was NOT an easy task. One trick was to use Nichrome wire, with a very well known resistivity per foot, then using a precisely cut length of the wire. It still took a great deal of faith, however...since we could never actually MEASURE the final product...we had to make some assumptions about the consistency of the resistivity of our spool of wire. It was probably very good, but we never really knew!

    One very old method is to take a bar or plate of copper, and file away at it until you had the right resistance....if you had a way of measuring it! Alas, even the finest DVMs don't really do well with really small resistances.

    You might also look up references on "4 wire resistors"

  5. KL7AJ

    AAC Fanatic!

    Nov 4, 2008