Description
The energy absorbed and released by transformer leakage inductances during each switching period usually ends up as loss, thus impairing switching power supply efficiency. Even when much of this energy is recycled and recovered through the use of resonant or active clamping techniques, leakage inductance remains as the main factor in cross-regulation errors among multiple outputs, a problem that cannot be eliminated ore reduced with a single control loop. This topic discusses how proper thinking about leakage inductance can lead to construction techniques to minimize it (and thus minimize the closely related ac winding loss), as well as how to optimize the winding hierarchy to reduce cross-regulation errors. Also discussed are ways to use reluctance modeling and duality principles to develop the equivalent electrical circuit model of a transformer to provide the best visibility of the effects of transformer parasitic inductances. Examples are presented of forward and flyback transformer applications with multiple outputs.

Objective

Key Learning

Course Modules
1. Transformer and Inductor Design for Optimum Circuit Performance (ATECH2-4)