Question

How do you reduce the eddy current loss of a transformer?

Answer 1

Eddy current loss in a transformer happens when the alternating magnetic field induces circulating currents (eddy currents) in the iron core. These currents cause energy to be wasted as heat.

To reduce eddy current losses, here are some simple methods:

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✅ 1. Use Laminated Core:

1. What it means: Instead of using a solid iron core, the core is made of thin metal sheets (laminations).
   

1. How it helps: Each thin sheet is insulated from the others, so eddy currents can't flow in large loops. This reduces the loss.
   

1. Think of it like: Cutting a big loop of current into many small loops = less heat.
   

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✅ 2. Use High-Resistivity Material for the Core:

1. Example: Silicon steel is commonly used.
   

1. Why it helps: Higher resistivity opposes the flow of eddy currents, so less current flows, and less energy is lost.
   

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✅ 3. Apply Insulation Between Laminations:

1. Each sheet in the laminated core is coated with varnish or oxide layer.
   

1. This insulation blocks eddy currents from jumping between sheets.
   

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✅ 4. Reduce the Thickness of Laminations:

1. Thinner sheets = lower eddy current loss.
   

1. Common thickness is around 0.35 mm or less for better performance.
   

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✅ 5. Use Ferrite Core (for high-frequency applications):

1. In devices like SMPS or high-frequency transformers, ferrite cores are used.
   

1. Ferrite has very high resistivity, so it almost completely blocks eddy currents.
   

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In Simple Words:

> "To reduce eddy current loss, break the core into thin slices (laminations), use materials that don’t let current flow easily (like silicon steel or ferrite), and make sure each slice is insulated."

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Let me know if you want a diagram or animation idea for this – might be a good YouTube explainer!