Experimental Characteristics of Electret Generator, Using Polymer Film Electrets

Abstract

An experimental electret generator has been developed to examine its operating theory. Although the generator is essentially a simplified version of Jefimenko's electret generator, it has none of the shortcomings of his generator. Since the electret used in our generator is a Teflon FEP film electret retaining stable homocharge, it does not have to be shielded. Our generator is of the single-ended-output type; therefore the electret need not have mechanical strength. The generator is a typical parametric machine which has the simplest structure. The fundamental electrical characteristics of the generator are derived experimentally. The experimental characteristics agree well with the theoretical ones. The maximum power obtained when the revolution number equaled 5000 rpm was \fallingdotseq1.02 mW.