Tutorial: Switch Mode Power Supplies And Their Magnetics

By Datatronic

In today's day and age the most often used topologyfor electronic power supplies is that of the Switch Mode Power Supply (SMPS), which is a major user of magnetics.

In some applications the "older type" linear supplies are still used, but in the early 70's SMPS came into being spurred by the development of faster switching transistors. This facilitated the use of much smaller magnetic components and greater efficiencies.

In general, there are four different types of magnetic components that are needed for the typical SMPS. They include the Output Transformer, usually the most noticeable because of its size compared to the others, the Output Inductors, the Input Inductors and the Current Sense Transformer, each with its own important function.