Analysis of Quality Factor of Annular Core Inductors
01 January 1960
The analysis of annular magnetic core inductors in terms of the desired characteristics and the properties of their components entails adjustments of core and winding dimensions, and the selection of best arrangements for each set of requirements. The present paper summarizes the methods in use during the past 25 years at Bell Telephone Laboratories. Such analysis involves consideration of numerous properties of core and winding, some of which may occasionally be negligible. It will be illuminating first to make an analysis based upon the fewest basic properties. Subsequently the contributions and complications of secondary properties will be treated, as their need becomes apparent. I I . SIMPLE ANALYSIS 2.1 Magnetic Core The inductance of a winding of N turns on an annular core is L = 4iV>/i X 10"9 ^ 105 , henry, (1)