PERMANENT MAGNET MATERIALS MANGANESE ALUMINIUM

摘要

There are other factors besides power consumption that determine whether an electromagnet should be replaced by a. permanent magnet. The most fundamental is that;to produce the same field as an electromagnet may need a greater weight of permanent magnet material. This affects both the cost and;the power/weight ratio of the motor. To compare the relative volumes of electromagnet and permanent magnet needed for a given-field, then, it is useful to consider the former as a permanent magnet;with a rectangular hysteresis loop and to estimate a (BH) max product. The coercivity may be taken as the field produced by the windings and thenremanenceras the mean, fluxvdensity of the iron core and the copper wire.