Kool Mu Powder Cores

What is Kool Mµ®?

Magnetics Kool Mu cores are distributed air gap cores made from a 85% Iron, 9% Silicon, and 6% Aluminum alloy powder for low losses at elevated frequencies. Kool Mµ® material’s low loss and relatively high saturation level (10,500 gauss) make it excellent for use in power factor correction circuits (PFC) as well as unidirectional drive applications such as Pulse Transformers and Flyback Transformers. The near zero magnetostriction makes Kool Mµ ideal for eliminating audible frequency noise in In-Line Noise Filters and Inductors.

For more technical information, view the official Magnetics Kool Mu technical information, or view the Kool Mµ Material Property Curves

What applications are Kool Mµ cores best suited for?

Kool Mu Powder Cores are naturally suited for the energy storage filter inductors used in switch-mode power supplies. The 10,500 gauss saturation level of Kool Mu cores provides a higher energy storage capability than can be obtained with gapped ferrites of the same size and effective permeability.

Where significant ripple may contribute to heat rise, Kool Mu cores perform better than powdered iron cores in these respects. In similar applications, it is possible that Kool Mu cores will offer a reduction in core size over powdered iron cores.

Kool Mu cores are ideal for in-line noise filters where the inductor must support large AC voltage without core saturation occurring. Line filters using Kool Mu cores can be smaller in size, requiring fewer turns than by using ferrite cores. Kool Mu cores are also near zero in their magnetorestriction coefficient, meaning that they are extremely quiet when operating with audible frequency range noise or line current.

The high flux density and low core losses make Kool Mu cores excellent for use in power factor correction circuits as well as unidirectional drive applications such as pulse transformers and flyback transformers.

What are the advantages of Kool Mu Cores?

High Saturation

Lower core loss than Powdered Iron (see graph below)

Moderate cost

Low Magnetostriction

Very high Curie temperature

Stable performance with temperature

Variety of shapes available (E Cores, U Cores, Blocks, Segmented Cores, etc.)

Core Loss for Kool Mµ versus Powdered Iron

What advantages do Kool Mµ E Cores offer over gapped ferrite E cores and powdered iron cores?

The 10,500 gauss saturation level of Kool Mμ provides a higher energy storage capability than can be obtained with gapped ferrite E-cores, resulting in smaller core size. Kool Mμ E cores are competitively priced against gapped ferrite E cores and their distributed air gap eliminates gap loss problems associated with ferrites. Kool Mμ E cores have significantly lower losses and substantially better thermal properties when compared to powdered iron E-cores. Kool Mμ E-cores have significantly lower losses and substantially better thermal properties when compared to powdered iron E cores.