Coupled inductors are components identified by the presence of two or more windings on a common core. They are used extensively in electronic applications such as radio transmission and are commonly found in DC-DC convertors and operate by transferring the energy from one winding to the other via the common core that they share. In order to protect them from electromagnetic interference (EMI) that may occur, most coupled inductors are magnetically shielded.
Coupled inductors vary in size, inductance values and current ratings. They may have equal coils in each winding (1:1) or varying/unequal coils (1:N).