Reconsiderations of basic motor and generator action: The nature of the new control techniques

The application of electronic controls to electric motors and generators has the appearance of a mere merger of two somewhat divergent practices of a common engineering discipline. It is, however, much more than this! It taxes the ingenuity of the practical man and challenges the imagination of the theorist. Indeed, such a merger has evolved as an excellent illustration of applied science. For instance, one might consider such recent innovations as motors with superconducting field mag nets, homopolar machines with liquid-metal contacts, magneto-hydrodynamic generators, commutatorless dc motors, printed-circuit motors, levitated induction drives for transport vehicles and, of course, the application of solid-state devices to all types of electric machines.

The nature of the new control techniques

As the author, I assume in this guide that you have at least a basic knowledge of electrical and electronic devices. Accordingly, I will not attempt to duplicate the con tents of the other guides already available on electricity, magnetism, and electronics.

This section explores the known, with deliberate intent to invoke the unknown. It touches on elemental notions to show how accepted principles band together to produce useful hardware. Basic questions are raised, but the very contemplation thereby initiated will, in itself, constitute my objective. From this study, I hope you will realize that electric machine technology, though rooted in the past, is destined for a profuse blossoming in the future.

Let us commence with a discussion of a feature common to all motors that convert electrical to mechanical energy—the phenomenon of action at a distance.