Abstract
Due to the merits of minimum parts count and high reliability, switch mode power supplies below 100 Watts are usually realized with flyback converters. In spite of the simple circuit, there are so many parameters to be determined for given specification. In addition, too many trade-offs remain to be made by design engineers. As a result, for a given specification, the final designs resulting from different engineers may show quite big difference. In view of this, the main purpose of this thesisis to find a loss reduction oriented design method for constant frequency flyback converters under the constraints of approximately equal cost and volume. In other words, it is assumed that the adopted MOSFET and Diode specifications are fixed for cost consideration and the core of thecoupling inductor as well as the capacitor is also kept unchanged for volume constraint. Hence, only the number of turns of the windings and the copper wire size remain to be optimized. Under the proposed method of this thesis, a circuit engineer can finish the design without manydo-loop optimization.