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Homework Help: The influence of crossing angle on amplitude in cable to cable coupling

  1. Mar 2, 2010 #1
    1. The problem statement, all variables and given/known data
    Hi all,
    I have this project i have to write but i am having trouble getting the necessary materials to aid my writing. The project topic is the influence of crossing angle on amplitude in cable to cable coupling. It is a magnetic coupling problem and i am supposed to design a workbench to demonstrate it.



    2. Relevant equations
    I need to interpret data from the experiment.


    3. The attempt at a solution
    I tried to analyze it in this manner: An experimental set up to demonstrates the influence of magnetic field coupling from an power cable to a nearby signal cable.The experimental set would demonstrate the impact of parallel cable layout as well as when the cables cross.
    What happens when a power/signal cable is placed in close proximity to the cable not carrying current or carrying a signal of a different frequency?
    Please find attached pictures of a workbench with the cables placed in parallel.
    Thanks, i would appreciate any help.
     

    Attached Files:

  2. jcsd
  3. Mar 2, 2010 #2

    berkeman

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    Staff: Mentor

    Welcome to the PF. Your pictures show coaxial cables -- are you trying to model crosstalk between coaxial cables? That coupling should be quite low, and is generally not an issue that I am aware of.

    You mention a power cable and a signal cable in the text of your post -- that is quite different from the pictures. What are the constructions of the power and data cables?
     
  4. Apr 19, 2010 #3
    I was able to model something. I used two coaxial cables, one of the cables i connected to a signal generator, the other i connected to an oscilloscope, and crossed both cables. The cable connected to the scope i moved, varying the angles between both cables.
    I saw some induced voltage but the voltage did vary even after varying the angles between both cables. The whole idea of the project is to get the readings of the induced voltage at different angles between both cables. I don't know if i should blame it on the scope because it is quite old.
    I would really appreciate any help i can get and any articles/journals/papers highlighting induced voltage and how to calculate it.
    Thanks.
     
  5. Apr 19, 2010 #4

    berkeman

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    Staff: Mentor

    Are you terminating the coax cables in their characteristic impedances? Honestly, cross-talk between coax cables that are handled properly (even when run together) will be minute.

    The search terms you should use are Near End Crosstalk (NEXT) and Far End Crosstalk (FEXT):

    http://www.answers.com/topic/unger-model

    You can find some experimental help by using those search terms.
     
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