Air coil
Air Coil Inductors
Ferrite honeycomb coil
The honeycomb coil is wound in a crisscross manner to reduce distributed capacitance. It is used in the tuning circuits of radios in the ranges of medium and long waves, thanks to the shape of the winding achieving inductively high values in low volume.
Toroidal core coil
A simple coil wound on a cylindrical form creates an external magnetic field with a north and south pole. A toroidal coil can be created from a cylindrical coil by bending it into a doughnut shape thereby merging the north and south poles. In a toroidal coil, the magnetic flux is largely kept internal to the coil. This results in less magnetic radiation from coil, and less sensitivity to external fields.
Various types of inductors
