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On physical processes in showering arcs

Discussion in 'Electronic Basics' started by Sergey Karavashkin, Mar 9, 2005.

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  1. Dear colleagues,

    I would like to share with you 75 jubilee celebration of a talented
    scientist and one of my teachers of which you did not know, my Mother
    Dyna P. Karavashkina,

    Many years ago we two undertook a study which, as you will make sure,
    still remains actual, because today contact sparking remains one of
    the main problems of electric engineering. Semiconductors only in some
    cases are able to substitute contacts, but not in case when we need to
    switch the circuit fully off. ;-)

    Now I would like to suggest to your attention the paper written after
    materials of that old discovery,

    *Phenomena at electric contacts breaking direct-current inductive


    This paper is devoted to theoretical and experimental study of
    physical nature of unstable discharges arising in contact gaps when
    opening inductive load. We revealed that despite conventional opinion,
    showering arcs are alternating relaxations. Each of them consists of
    two stages: monotonous exponential growth of voltage related to the
    charging of parasitic capacitance of gap which is shunted by metallic
    bridges, and of high-frequency high-voltage oscillation process
    related to the high-frequency spark process within the gap. With it,
    metallic bridges are produced in each period of unstable discharges.
    We analyse the conditions and stipulate the physics of processes of
    such bridges formation. We established that the cause of bridge
    formation is the electric pressure in high-voltage oscillation process
    preceding the monotonous period of unstable discharge. The second
    cause are plasma jets able to strap even larger gaps than those
    typical for unstable discharges. The experimental results obtained
    after this theoretical study fully corroborated the described pattern
    of physical processes in showering arcs. On the basis of developed
    method to obtain the dynamic curve of breakdown voltage and noting the
    experimentally corroborated physics of processes, we have successfully
    carried out the work on practical protection of relay contacts working
    under inductive load, and presented the result of this protection.

    Enjoy reading full text:

    Hopefully, this study will be of your interest. It will be my pleasure
    if someone, having looked through our work, will get to see the world
    wider and more versatile, and that problems of physics are not
    confined to Lorentz transformation, Schwarzschild sphere and
    Schroedinger equation. ;-) Here also are very many subjects for

    Best to you all,

    Sergey B. Karavashkin

    Head Laboratory SELF
    187 apt., 38 bldg.
    Prospect Gagarina
    Kharkov 61140

    Phone: +38 (057) 73706624
    e-mail: ,
  2. Fred Abse

    Fred Abse Guest

    I think that should be "monotonic"

    Still apposite, though :)
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