ABSTRACT
This chapter describes magnetic properties of transformer steels. Inductors are passive components in which voltage leads current by nearly 90° over a wide range of frequencies. Inductors are usually coils of wire wound in the form of a cylinder. In magnetic materials, such as iron, cobalt, and nickel, the electrons in the third shell of the atom are the source of magnetic properties. In effect, the shielding of components and circuits from magnetic fields is accomplished by the introduction of a magnetic short circuit in the path between the field source and the area to be protected. The effectiveness of shielding depends primarily upon the thickness of the shield, the material, and the strength of the interfering field. Inductors have resistive losses because of the resistance of the copper wire used to wind the coil. Air-core inductors are used primarily in radio frequency applications because of the need for values of inductance in the microhenry or lower range.
