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Self capacitance of a multi layer coil

  1. Mar 26, 2012 #1
    Hi everyone,

    I am trying to figure out how to correctly calculate the self capacitance of a multi layer coil.

    I have been trying to find an online calculator or software which can do this but I don't really know where to look.

    Just hoping someone here can give me some insight. Any help will be greatly appreciated!
  2. jcsd
  3. Mar 27, 2012 #2


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    Staff: Mentor

    Perhaps you'd better define "self-capacitance". Self-inductance I can grasp, self-capacitance is more nebulous. Can you draw a schematic and show a capacitor marked "self-capacitance"?
  4. Mar 27, 2012 #3


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    Science Advisor
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    At a low frequency, the self inductance should be fairly easy to calculate if the coil is of standard construction. The self capacitance is something that will be much harder to determine because it will be frequency dependent. There is a capacitance 'between the connecting terminals' (in parallel with the nominal L) because of the proximity of the turns at each end and this will resonate (parallel resonance) at a certain frequency with the L and increase the effective impedance of the coil. This frequency can be found experimentally with a sweep oscillator but is very hard to predict. I would search with terms like "RF coil winding techniques" and "Parasitic capacitance of coils"

    I found this.
  5. Mar 27, 2012 #4
    The Book "Electronic Transformers and Circuits" by
    Reuben Lee, Leo Wilson & Charles E. Carter has two pages describing how to calculate the distributed capacitance of a transformer coil.
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