3 Main Types Of Magnetic Cores Used In Transformers

A transformer can help in transfer of electrical energy between circuits through the help of electromagnetic induction, only with the presence of a magnetic core within it. This magnetic core is a piece of magnetic material that has high magnetic permeability to direct magnetic fields within the transformer. The magnetic field is created when a coil of wire carrying a current is wound around the core. This magnetic field can be increased by a factor of thousands with the presence of the core!

How much power, voltage and current a transformer can provide depends on the properties of the core. The dimension and geometry of the core, the properties of the core’s material, the operating temperature of the core, and the amount of air gap in the magnetic circuit are some factors that determine the properties of a transformer.


Magnetic cores used for industry applications are available in different sizes, frequencies, voltage ratings and many different types. Different industry types use different core types. Here is a brief overview of the three main types of cores used in transformers.

Solid iron or steel

Steel and iron have been one of the most common materials used for constructing cores. They serve as an excellent pathway for magnetic flux, allowing the magnetic field to be very high without saturating the material. They provide sturdy magnetic fields and generate enough heat required, thus boosting the overall performance of the transformer. However, being a good conductor of heat, they also result in massive heat generation and thus inefficiency at very high operating frequencies. This is the reason why iron and steel are becoming fairly uncommon today.

Laminated silicon steel

These cores have thin silicon alloy laminations stacked one over the other. These alloys provide great magnetic pathways but, don’t conduct electric current. Instead of a solid piece of iron or steel, these thin layers result in reduced eddy currents and electrical pathways. Thus, the efficiency of transformers using these alloys increases greatly. With reduced vortex current and heat dissipation, these magnetic cores make the transformers last longer, thus requiring lesser maintenance efforts and costs. These cores are highly replacing solid iron and steel cores.

Amorphous steel

Amorphous steel cores are made up of many layers of paper-thin metallic tapes stacked together. They work on the same idea as laminated silicon steel but, with better efficiency. This is because the super thin strips reduce the flow of eddy currents even further, due to which there are lower losses and higher operating efficiency even at higher frequencies. These cores are commonly used in medium frequency and high efficiency transformers.

These three different types of cores are used to build different types of transformers like step-up, step-down, auto, three-phase, rectifier and many others. Whatever your industrial need, choose the one that suits your requirements the best and opt to buy it from Miracle Electronics, the largest transformer manufacturer in India, who provides 100% assurance and guarantee of high quality and tested products.