ABSTRACT
This chapter treats the specific aspects related to inductors, in general, and the design of special inductors.
The inductance of air coils and toroidal cores is presented at the beginning. Air coils were historically important and are still used if accurate values are needed, as they are not influenced by the characteristic of magnetic materials. Compared to air coils, much higher energy and apparent power densities are obtained using coils with cores of magnetic materials. With high permeability materials, air gaps are necessary to improve the energy storage. Usual shapes for laminated iron are given in this chapter. For inductors with air gaps, methods to estimate the additional permeance due to fringing fluxes are also presented.
