A comparison of the ladder and full-order magnetic models

Predictions of the reduced-order ladder model and the full-order extended cantilever model are compared with the measured behavior of an experimental multiple-output flyback converter. The flyback transformer geometry was chosen to closely follow the idealizing assumptions that lead to the ladder approximation, including use of a pot core with full-width copper foil windings. In spite of this, the ladder model fails to predict the observed waveforms and the mode of operation. The full-order extended cantilever model does indeed correctly predict the operating mode and the observed waveforms. Model parameters are measured using a network analyzer. Conditions on the validity of these measurements are derived using Middlebrook´s extra element theorem