Observations on the Theory and Characteristics of Electrical Figures on Plates in Air with Particular Reference to their Speed of Growth

Author: Pleasants, John Gibson

Year: 1933

Degree: Dissertation (Ph.D.)

Advisor: Unknown, Unknown

Committee Member: Unknown, Unknown

Option: Electrical Engineering

DOI: 10.7907/8EFG-G165

Abstract

The fact that electrical figures in air at atmospheric pressure grow with average velocities which lie in the range of from 10 to 103 km./sec., and which may extend beyond this range, depending on the magnitude of the voltage applied and the physical constants of the plate is verified. The velocity decreases with increasing size of the figure. The effect of a variation in the capacitance between surfaces per unit area of the plate has been found to be greater for negative than for positive figures, and has been found to decrease with increasing voltage, for figures at the same stage of development. The maximum current intake has been observed to be 22.5 amp. (an average for two figures in parallel) at 30 kv., rising to a value of 60 amp. at 42.5 kv.. The effective capacitance (of two figures in parallel) in one case rose from an initial value of practically zero to more than 8,000 cm., resulting in a reduction in maximum value of the voltage wave applied of 25% of the open line value. The reduction in rate of rise of voltage for the same case was 30%. The possibility of the use of such an arrangement for protection against over voltages is suggested. The polarity difference in the figures is a result of the difference in direction of the flow of charge, and is dependent on the constants of the plate, - - no predisposition to a fixed ratio being noted. The behavior of the figures is such as to verify the conclusions of other authors that figures of both polarities are formed by the movement of electrons alone.

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