APPROACHES TO PERMANENT-MAGNET CIRCUIT-DESIGN

The advent of high-coercivity /high remanence magnet materials has gre atly extended the range of applicability of permanent magnets so that many formerly impracticable devices are now viable. This paper discuss es some of the more fruitful approaches to the use of these materials in magnetic circuit design and how application of comparatively few an d simple techniques can result in a large number of useful devices. Th e approaches discussed are estimation of permeances, magnetic cladding , equivalent pole densities and current sheets, analytic application o f Maxwell's equations, the magnetic moment rotation theorem and magnet ic ''mirrors''. Some novel devices resulting from these applications a re cited.