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Dielectric Recovery of Short A-C Arcs Between Low-Boiling-Point Electrodes

Citation

Browne, Thomas Everett (1936) Dielectric Recovery of Short A-C Arcs Between Low-Boiling-Point Electrodes. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/2G7K-6814. http://resolver.caltech.edu/CaltechTHESIS:10012015-143909827

Abstract

The re-ignition characteristics (variation of re-ignition voltage with time after current zero) of short alternating current arcs between plane brass electrodes in air were studied by observing the average re-ignition voltages on the screen of a cathode-ray oscilloscope and controlling the rates of rise of voltage by varying the shunting capacitance and hence the natural period of oscillation of the reactors used to limit the current. The shape of these characteristics and the effects on them of varying the electrode separation, air pressure, and current strength were determined.

The results show that short arc spaces recover dielectric strength in two distinct stages. The first stage agrees in shape and magnitude with a previously developed theory that all voltage is concentrated across a partially deionized space charge layer which increases its breakdown voltage with diminishing density of ionization in the field-tree space. The second stage appears to follow complete deionization by the electric field due to displacement of the field-free region by the space charge layer, its magnitude and shape appearing to be due simply to increase in gas density due to cooling. Temperatures calculated from this second stage and ion densities determined from the first stage by means of the space charge equation and an extrapolation of the temperature curve are consistent with recent measurements of arc value by other methods. Analysis or the decrease with time of the apparent ion density shows that diffusion alone is adequate to explain the results and that volume recombination is not. The effects on the characteristics of variations in the parameters investigated are found to be in accord with previous results and with the theory if deionization mainly by diffusion be assumed.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Electrical Engineering
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Unknown, Unknown
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1936
Record Number:CaltechTHESIS:10012015-143909827
Persistent URL:http://resolver.caltech.edu/CaltechTHESIS:10012015-143909827
DOI:10.7907/2G7K-6814
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9188
Collection:CaltechTHESIS
Deposited By: Benjamin Perez
Deposited On:02 Oct 2015 15:08
Last Modified:08 Apr 2019 18:05

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