It is nonsense to imagine that an air cored coil has a difference between magnetized field energy and demagnetized field energy. But this is not an air core as it has the permeable toroidal core within its ambit. If you measure the (open circuit, no load) voltage rise while the coil is receiving some magnetic field from that toroid then the integral of that rise wrt time will tell you the value of the field flux within the air core. You could then relate that to the energy that you would have got if the field came from current in the coil, and call that the magnetized energy. You could do this by calculation or by taking the toroid away and putting in your own current to get that flux value, then doing the math to get the energy. You could also do the integral of the voltage fall down to zero to get the value of the flux fall, and you would get the same values of flux and energy. An air cored coil does not and can not have different mag/demag energy.
Now the coil plus that toroid is not air-cored, so could that combination have different mag/demag energies? If so this will be a property of the toroid and that is another matter. You wont get the answer from that nonsensical charging of the two capacitors. The sensible thing to do there is to put a current pulse into the air core and measure the voltage rise and fall (a) with the toroid un-energized and (b) with the toroid energized. That will tell you a lot about the effect of that toroid on the system. You could play around with that data looking for OU.
On the subject of whether the toroid get saturated by the magnets, when using tape wound cores like metglas the core high permeability does not apply to the magnet's field being injected into the core radially, it only applied to the field along the laminations. The field from the magnet does not follow the field lines shown in the simulations that assume the permeability is isotropic. In fact they do not penetrate so far into the core, most of the field lines flow around the core in the laminations closest to the magnet. And that concentration will saturate that part of the core. This has interesting features that could apply to the MEG where flux from the input coils adds or subtracts from the magnet's flux in different halves of the core. That adding or subtracting alters the radial depth where the saturation region occurs, so we get a form of flux-gate pumping going on. The attached image show a simulation of the MEG core where the FEMM facility of having different values of x and y permeability is used to show the concentration of the magnet's flux in the inner laminations.
Smudge
Smudge, It is nonsense to imagine that an air cored coil has a difference between magnetized field energy and demagnetized field energy. But this is not an air core as it has the permeable toroidal core within its ambit. If you measure the (open circuit, no load) voltage rise while the coil is receiving some magnetic field from that toroid then the integral of that rise wrt time will tell you the value of the field flux within the air core. You could then relate that to the energy that you would have got if the field came from current in the coil, and call that the magnetized energy. You could do this by calculation or by taking the toroid away and putting in your own current to get that flux value, then doing the math to get the energy. You could also do the integral of the voltage fall down to zero to get the value of the flux fall, and you would get the same values of flux and energy. An air cored coil does not and can not have different mag/demag energy. you say: It is nonsense to imagine that an air cored coil has a difference between magnetized field energy and demagnetized field energyand An air cored coil does not and can not have different mag/demag energy.That is good to know and i think i have to agree after reading Nikolay E. Zaev his PDF again as he there talks about "Ferrites and Ferromagnetics Free Energy Generation", so its the ferrite / ferromagnetics as core that is generating the free energy according to him. So the output / air coil used by JN Naudin must be the vehicle to extract that energy from the ferrite. My air coil measures 16mH @ 1KHz and this increases to 18mH @ 1KHz when the toroid coil is placed ontop, with or without the magnets attached. I will try to follow your suggestion to measure / calculate the (even) mag. / demag. energy of the stand alone air coil to proof that it is correct what you are saying, but i am not sure i understand exactly how to do so. Now the coil plus that toroid is not air-cored, so could that combination have different mag/demag energies? If so this will be a property of the toroid and that is another matter. You wont get the answer from that nonsensical charging of the two capacitors. The sensible thing to do there is to put a current pulse into the air core and measure the voltage rise and fall (a) with the toroid un-energized and (b) with the toroid energized. That will tell you a lot about the effect of that toroid on the system. You could play around with that data looking for OU. So indeed the air coil is influenced by the toroid core (inductance 16mH v 18mH) so a difference in mag. / demag. energy could be caused by that. But you say: "You wont get the answer from that nonsensical charging of the two capacitors.", so what do i measure with that "nonsensical charging of the two capacitors"? I measure a clear difference in mag. / demag. energy. Anyway, i will try to follow your suggestion and "put a current pulse into the air core and measure the voltage rise and fall (a) with the toroid un-energized and (b) with the toroid energized." On the subject of whether the toroid get saturated by the magnets, when using tape wound cores like metglas the core high permeability does not apply to the magnet's field being injected into the core radially, it only applied to the field along the laminations. The field from the magnet does not follow the field lines shown in the simulations that assume the permeability is isotropic. In fact they do not penetrate so far into the core, most of the field lines flow around the core in the laminations closest to the magnet. And that concentration will saturate that part of the core. This has interesting features that could apply to the MEG where flux from the input coils adds or subtracts from the magnet's flux in different halves of the core. That adding or subtracting alters the radial depth where the saturation region occurs, so we get a form of flux-gate pumping going on. The attached image show a simulation of the MEG core where the FEMM facility of having different values of x and y permeability is used to show the concentration of the magnet's flux in the inner laminations.
Thanks for the info on metglas cores, the finemet core i have seems also tape wound, so will show similar effects as you describe. It is strange then i think that JL Naudin shows a FEMM simulation of a Nanoperm M-059 core which seems to follow other rules with no flux leakage etc. Thanks, Itsu
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Topic: Itsu's workbench / placeholder. (Read 137189 times)
