Leakage Reactance Transformers provide both transformation and relatively high reactance between the source and the load. They are defined as those providing an artificial leakage flux path between the primary and secondary windings. The basic Leakage Reactance Transformer consists of a core, a primary winding, a secondary winding, and a magnetic shunt that separates the primary and secondary windings. Leakage flux is driven through the artificial leakage flux path by the magnetic potential of the windings, and produces a voltage in the windings equal to an inductive reactance voltage drop in series with the load. The ratio of that voltage drop to the load current is the leakage reactance of the transformer, relative to the load circuit. The series reactance is composed of two main components, the energy stored in the shunt path air gaps, and the energy stored in the air path leakage fields through the core window and around the outside of the core. Leakage Reactance Transformers provide inherent current limiting, short circuit protection, and peak current reduction. They are commonly used for current limiting in applications such as welding, starting and ballasting gas-discharge lamps, for decoupling output circuits and as anode supply transformers in continuous wave magnetrons.
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