Influence of Improved Magnetic Alloys on Design Trends of Electrical Instruments

Small panel-type electrical indicating instruments are recognized as an and power control equipment, which is so essential in all military and naval operations on land, in the air, and on the sea. Such instruments are required to be small, compact, light in weight, and reliable measuring devices; and one of the major factors in the realization of these requirements is the efficient utilization of improved magnetic materials for permanent magnets. This paper describes properties of a new magnetic alloy and compares its characteristics with other permanent-magnet materials used in small panel electrical indicating instruments of the permanent-magnet moving-coil type. The use of a new cobalt-molybdenum-iron alloy as a permanent magnet material in an indicating instrument and its influence on design trends are discussed. The resulting improvement in overall instrument performance by the use of this new material is summarized, with particular reference given to mechanical factor of merit which is a measure of instrument reliability.