Ferrite Toroidal Cores

Ferrites Toroid Cores are generally used to introduce permeability, i.e. increased inductance for a given number of turns.
Toroids provide the following advantages:
High inductance for the physical space occupied.
No interaction or coupling with adjacent components (unlike air wound and other inductors).
Exceptional Q values when wound correctly and optimum core and windings selected.
Wide range of diameters and thicknesses.
Relatively low cost
Often simple to mount or secure mechanically.

Ferrites Toroid Cores are generally used to introduce permeability,