The property of a transformer design in which the transformer contains two separate magnetic paths with limited coupling between them. The output contains a resonating tank circuit and draws power from the primary to replace power delivered to the load.

A phenomenon characterized by overvoltages and very irregular wave shapes which are potentially damaging to a transformer. It typically occurs when there is no ground on the system except through the transformer connected line to ground. It is always associated with the excitation of one or more saturable inductors through capacitance in series with the inductor. When one or two phases are disconnected from the source by single-pole fault clearing or switching, it is possible for the transformer windings connected to the open phases to be excited through the system capacitances to ground and between phases.

Resonance resulting when the iron core of an inductive component of an LC circuit is saturated, increasing the inductive reactance with respect to the capacitance reactance. This is an undesirable effect in electrical distribution systems.

This term refers to a principle that is used in open-loop (non-feedback) power supplies that are intended to stabilize voltage.