Accession Number : AD0691889

Title :   A SURFACE CHARGE INDUCTION MOTOR,

Corporate Author : STANFORD UNIV CALIF INST FOR PLASMA RESEARCH

Personal Author(s) : Choi,Soon Dal

Report Date : JUL 1969

Pagination or Media Count : 96

Abstract : An electromechanical force generation mechanism involving interaction between moving media and a TM mode wave was studied. No restrictions were imposed on the wave and medium velocities. The medium with finite conductivity was assumed to be homogeneous, isotropic and linear, and to move with a uniform velocity. A relativistic transformation of the electromagnetic fields was employed to transform the electromagnetic fields in the frame of reference in which the medium was stationary to the laboratory frame of reference in which all the measurements were made. The dominant force mechanism was due to the electric field acting on the surface charge on the interface between the conducting medium and the air gap. The time average force mechanisms with the TM mode waves turned out to be due only to the electric field interacting with free surface charge due to the conductivity of the medium but not to the field acting on polarization charge. The theoretical efficiency of the electromechanical energy conversion of this type of waves was found to be identical with that for the conventional induction motor. To check the theory a surface charge induction motor whose rotor was made from a hollow cylinder of a dielectric material was built. The TM mode was generated with a 60 Hz three-phase circuit constructed from a set of uniformly spaced wires fed in groups of three. Speed and torque data agree with an analysis of the space harmonic fields produced by such a circuit. The device operated as a motor both in the forward and backward directions and above and below the synchronous speed of the fundamental wave. (Author)

Descriptors :   (*INDUCTION MOTORS, STATIC ELECTRICITY), ELECTROMAGNETIC RADIATION, INTERACTIONS, ENERGY CONVERSION, ELECTROMECHANICAL CONVERTERS, THEORY

Subject Categories : Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE