Most electrical transformers that I am aware of have either copper or aluminum cable wound around an iron core.

Can the iron core be replaced with a copper core? Would there be any performance differences?

  • $\begingroup$ You probably can, however the efficiency will be a lot lower due to magnetic field leakage. Namely the iron core has much higher magnetic permeability than air, while copper has even a slightly lower one, if I remember correctly. So an air "core" would probably be better than a copper core. I am not sure if other material properties might play a role as well so I only post this as a comment. $\endgroup$
    – fibonatic
    Commented Oct 25, 2019 at 9:01
  • $\begingroup$ You have many losses in transformers, usually the magnitude of copper (winding loses) dominant in compare to the Iron losses, by making the copper core, you'll increase the power-loss up to more than 70%. Besides the issues mentioned in the answer. Google the equivalent circuit of the transformer, you'll relize why. $\endgroup$
    – user14407
    Commented Oct 25, 2019 at 16:19

1 Answer 1


It would not be a good idea at all - a transformer is effectively a magnetic circuit, so you need a low reluctance path for the magnetic flux to flow through. Copper has a high magnetic reluctance, so would not be a good choice.




Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.