Electrical designs are continuously pushed towards high frequencies, lower weight and higher load with less distortions to and from the environment. And we should not forget the demands for materials savings, especially when looking at materials with scarcity like rare earth elements, lithium and copper.
A major part of passive power applications are found in inductors, filters and transformers where Soft Magnetic Composite solutions can give designers new possibilities when working at low to medium frequencies at a high saturation level.
Soft Magnetic Composites (SMC) are materials known as powder based cores, but compared to most of the other powder based materials SMC has a very high saturation level – typically above 1,8 tesla. Furthermore SMC can be produced in complex shapes with very narrow tolerances which enables slimmer and more compact designs.
This can be seen in damping applications in applications below 5 KHz, where the advantages of the high saturation level directly can save on the number of turns of expensive copper wire.
But it can also be used in applications where a stable permeability is needed over a larger flux span. On the curve it is shown that the permeability stays stable/high until around 0,8 tesla. This is relatively high compared to competing materials that typically drops off around 0,2 tesla.
A normal core design typically distribute the losses between the copper and the core equally, but in some applications it can be advantageous to place the major losses in the core as thermal management of the core is a lot easier than on the enclosed cupper wire. Furthermore it is possible to design cooling fins or place heat sinks directly on the outside of a pot core as shown on the photo below.