The moving-coil voltage regulator

The general problem of voltage regulation under load is reviewed and the principal technical and operating characteristics of existing voltage-regulators are summarized. The problem has not been found easy of solution, as the more simple devices are restricted in scope and have other technical limitations, whilst apparatus of more general application is relatively expensive and complicated. A recent developmentis described which in principle involes an isolated and short-circuited coil moving up and down the leg of a laminated iron core over fixed coils. Smooth voltage variation over any desired range is obtained without switches, contacts, flexible leads, or windings in slots. After a discussion of the new regulator, the special features and application of regulators are considered under the separate headings of voltage control (a) in transmission and distribution circuits, and (b) for industrial and laboratory purposes.