https://en.wikipedia.org/wiki/ElectromagnetQuoteA core can increase the magnetic field to thousands of times the strength of the field of the coil alone
The quote above from wikipedia seems to indicate it is overunity.
But I remember seeing this subject discussed on another thread( I can't find that thread at the moment ) just some months ago, and they mentioned that the core 'condenses' the field of the coil, and they also used the example of one of those electromagnets that keeps doors closed or open, those electromagnets have no range at all, in other words they only work if the metal-plate is touching the electromagnet.
However, I thought that the cores in electromagnets function by having all their atoms lined up in one direction by the field of the electric-coil, so that if it is true to say that
"A core can increase the magnetic field to thousands of times the strength of the field of the coil alone" then that may be the best example of energy-amplification via geometric means, that I know of.
Also
- I don't actually know what happens if you run a wire-loop from one side of the
"core" of the electromagnet to the other side of the electromagnet, surely there is no impressive current produced.
- That also made me wonder about people's attempted overunity designs consisting of coils inducing current in other coils, is it possible that the coils being induced, are functioning as electromagnets
"A core can increase the magnetic field to thousands of times the strength of the field of the coil alone" , that because of the 'correct' specifications' of these Secondary-Coils/Induced-Coils( wire-thickness, diameters, I don't know ), that they are able to achieve a greater output than the input of the primary-coils.
Keeping in mind, that some coils in attempted overunity devices have a core, while others just have air-cores, but for the above paragraph I was thinking as simply as possible and just thinking of all air-cores.
This is a subject I know nothing about.