What is Skin effect: Definition and 41 Discussions

Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor such that the current density is largest near the surface of the conductor and decreases exponentially with greater depths in the conductor. The electric current flows mainly at the "skin" of the conductor, between the outer surface and a level called the skin depth. Skin depth depends on the frequency of the alternating current; as frequency increases, current flow moves to the surface, resulting in less skin depth. Skin effect reduces the effective cross-section of the conductor and thus increases its effective resistance. Skin effect is caused by opposing eddy currents induced by the changing magnetic field resulting from the alternating current. At 60 Hz in copper, the skin depth is about 8.5 mm. At high frequencies the skin depth becomes much smaller.
Increased AC resistance caused by the skin effect can be mitigated by using specially woven litz wire. Because the interior of a large conductor carries so little of the current, tubular conductors such as pipe can be used to save weight and cost. The skin effect has practical consequences in the analysis and design of radio-frequency and microwave circuits, transmission lines (or waveguides), and antennas. It is also important at mains frequencies (50–60 Hz) in AC electrical power transmission and distribution systems. It is one of the reasons for preferring high-voltage direct current for long distance power transmission.
The effect was first described in a paper by Horace Lamb in 1883 for the case of spherical conductors, and was generalised to conductors of any shape by Oliver Heaviside in 1885.

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  1. Q

    I What causes skin effect in AC currents?

    My assumption has been it is the electromagnetic field starting from the center of the wire that pushes the electrons outward. However, this would also be true of a DC current, but it isn't. So why does an AC current cause electrons to move toward the skin of a wire? I don't recall ever seeing...
  2. Sibilo

    I Does the Skin Effect cause charge to accumulate on the surface of a conductor?

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  3. Narayanan KR

    A Question on Skin Effect and Eddy Currents

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  4. G

    Skin effect and electric shock question

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  5. Jackson Lee

    Why Does the Skin Effect Not Reverse into a Core Effect in AC Conductors?

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  6. E

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  7. E

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  8. T

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  9. Anton Alice

    I What is the connection between the skin effect and electromagnetic waves?

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  10. Cedric Eveleigh

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  11. dreens

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  12. G

    Understanding Skin Depth in DC and AC Fields: Confusion and Clarification

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  13. Dorian Black

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  14. L

    AC current skin effect due to eddy current?

    is skin effect of ac due to eddy current?
  15. H

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  16. A

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  17. P

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  18. N

    I understanding how skin effect works

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  19. R

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  20. V

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  21. Y

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  22. E

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  23. B

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  24. C

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  25. L

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  26. D

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  27. K

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  28. N

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  30. D

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  31. R

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  32. Y

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  33. C

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  34. H

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  35. A

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  36. Phrak

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  37. C

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  38. J

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  39. C

    What Causes the Skin Effect in High Frequency Currents?

    Can anybody explain the skin effect more clearly- why does the current tries to concentrate more closely to the surface of the conductor at high frequencies? what is happpening inside the conductor? thanks
  40. F

    Can potato skin effect the rate at which catalase breaks down hydrogen peroxide

    can potato skin affect the rate at which catalase in potato discs breaks down hydrogen peroxide? does potato skin contain the polysacharide cellulose?
  41. M

    Skin effect or total crossectional area

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