Coosing a Current Shunt.

Discussion in 'General Electronics Chat' started by R!f@@, Apr 1, 2014.

  1. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    The supplies I had in mind can Supply 10 to 12 Amps .

    I like to chose a current shunt. I chose this.

    Will it be suitable or do I need to go for high rating like 20A.

    I never used these before.
    I like to know the what the data actually says.

    I am thinking that if it says 75mV 15A, it will drop a total of 75mV when 15A of current flows through it.

    OR is it 75mV per 1 Amps ?
    Last edited: Apr 1, 2014
  2. MaxHeadRoom


    Jul 18, 2013
    It should have a resistance rating also, if the numbers are correct it would be .005Ω?
    Volt drop at 15amps.
    R!f@@ likes this.
  3. odinhg

    Active Member

    Jul 22, 2009
    The downside with buying components from eBay is that they usually don't provide a good datasheet or complete specifications.

    But for all the current shunt resistors I have used in the past, the current rating have been for continuous operation. So a 15A shunt should be enough.

    I'm pretty sure it is 75mV/15A (5mΩ). Also based on previous experience.
    R!f@@ likes this.
  4. alfacliff

    Well-Known Member

    Dec 13, 2013
    the 75 mv indicates that it is to be used with a 75mv meter, and voltage drop acorss the shunt is 75mv at 15A. if you use a shunt with .001 Ohm,you would read 15 mv at 15 amps. most of these surplus shunts were not designed with digital meters in mind.
    R!f@@ likes this.
  5. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
    Thanks guys.
    I am making my own meter here.
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    I've bought a few of these off EBay, different values but similar when I needed a .0025 ohm reference resistance.

    My $3000 Keithley micro ohmmeter says it is spot on. Had to snag it away when a load bank needed a sense resistor and 20A thru the 30A rated device goes on all day.

    They have an excellent Kelvin terminal arrangement. I used similar decades ago that were 10 times the price.
    R!f@@ likes this.