Typical curves, as furnished by the Al-legheny-Ludlum Steel Corporation, are included in this text for the purpose of providing reliable technical information for use in making calculations as described in a following chapter.

Tables, Charts, Graphs and Formulas

"B-H" curves for each of the types of steel listed in the preceding paragraphs, as well as curves showing the variation of core-loss characteristics of each grade with frequency and flux-density, are included in Figures 27 to 33 inclusive. Additional sets of curves (Figures 34 and 35) have been calculated and plotted from information provided by the Alle-gheny-Ludlum Steel Company. These show the variation in core-loss coefficients for the various grades, so that the approximate core-loss for any actual frequency and flux-density involved in the design can be calculated. This data is valuable when making comparisons of optional designs so as to secure the lowest over-all loss characteristics of core-loss, copper-loss, and magnetizing current.