Magnetic fields within a toroid inductor.

[Farmhand]

AS far as my telling people to disregard MileHighs post in the Coil For Electromagnets thread, I said that because I felt a lot of posts were distracting from the actual effect Tesla intended to show.

Tell me MileHigh do you still deny that the voltage applied to a Coil For Electromagnets as described in the patent will change the resonant frequency due to capacitor plate separation distance and "effective" capacitance secured as a result of the voltage applied ?

If the plates are a certain distance apart then a certain voltage is required to secure the full capacitance possible. Simple.

I also described Synchro as an extremist, and in the context of that thread I felt it was true. The theory is sound. Tesla describes it in his patent and I explained how it is so.

Did Tesla lie about the claims ? I say no. The thread had nothing to do with the possible uses of the coil. It was to investigate the validity of the patent claims. They are true and correct. Yet some very educated people denied that was even possible. Gotta wonder who has the ego.

I say we all have ego's and ego is not a dirty word. 

Just like this song by Skyhooks explains. 
http://www.youtube.com/watch?v=UduuxKdPt9Q

Cheers

[MileHigh]

Farmhand:

This is off topic but there are no substantive claims made in the patent.  You are reading something into the patent that is not there.  The patent just describes the architecture of the physical coil and says that it will have no impedance at the self-resonant frequency which is exactly what is supposed to happen.  It's a patent that tells you how to build something and makes a comment about how it will behave at the self-resonant frequency.  Beyond that there are no claims.  And yes, the capacitance is not a function of the voltage in a general sense and I see no reason that the Tesla bifilar coil would have any special capacitance vs. voltage relationship.

Beyond that, to say "don't listen to that guy" on a discussion board is inappropriate to the extreme.  How would you like it if somebody said to ignore all of your postings?  Take that to the limit and you don't have a forum anymore.

Anyway, that's all water under the bridge and nobody that I am aware of ever made a significant demo of a "series bifilar coil" that showed any special redeeming qualities above and beyond a regular coil or above and beyond a regular coil in parallel with a tiny capacitor.  As far as I am concerned this is just over reading of a document from the 19th century and imagining you can apply it to all sorts of unconnected and unrelated applications without any rational reason behind it.

Sorry Tinman, back to your thread.  With respect to your clip, using a magnet as a core does not make any sense.  I know that you see it being done everywhere but the simple fact is that it does not make any sense.  The purpose of the core is to allow itself to get polarized in any direction so that it can store magnetic energy.  A magnet as a core is already polarized in a fixed direction and by definition is not designed to store magnetic energy.

MileHigh

[Pirate88179]

MH:

What about a core made from a neo magnet that has been heated above the currie temp. to demagnetize it?  Would the properties that allow such a strong magnetic field to be had from the neo make it a good core choice then?  Or, would it try to be magnetized when the field is on and then not collapse?  The best thing I can find so far is Metglas.

Bill

[MileHigh]

Bill:

I haven't read up on magnetic core properties in a while but without brushing up on the subject I am quite certain the answer is no.  I am assuming that the raw unmagnetized  neodymium material has a very fat BH "S" curve.  In other words it has a fat hysteresis loop and the area inside the hysteresis loop represents lost energy after you do a complete travel around the loop.  It also would have very high remanence (also shown in the BH curve) and that's the last thing you want in an inductor core.  You want the core to be made of a material that can easily be temporarily magnetized and just as easily give up all of that stored magnetic energy (low remanence) and go back to a neutral state, all with a minimal loss of energy.

From what I recall a Metglas core has next to zero remanence and very high permeability and they make it in ribbon-like spools that form insulated layers to keep eddy current losses to a bare minimum.  I believe it's an expensive and exotic way to implement a core and as a result its very high in performance.  One assumes that for more "mainstream" cores the standard core materials are still in use because they are much cheaper.  Take this all with a grain of salt because I don't regularly scour the Internet reading up on cores.

Going back to using magnets in cores, a point that I made a few times is that the magnetization of the core can't by definition affect anything.  The magnetization is a DC-type phenomenon and all the "action" is in the realm of AC.  So the magnetization is invisible and has no affect on the AC circuit.  You just end up with a magnet doing a lousy job as a core.  You often see people posting, and you see free energy propositions, where people claim that using a magnet as a core means that the magnet will give an "extra kick" to the return energy but it's not true, it's just an old wives' tale.  All that you have to do is build your circuit twice, one version with a proper core and the second version with a magnet as a core and compare them if you are the type that needs to prove these things for yourself.  However, in this case, understanding all of the issues is ten times more important than building a test circuit.

MileHigh

[tinman]

@MH
Quote: Going back to using magnets in cores, a point that I made a few times is that the magnetization of the core can't by definition affect anything.

So i guess this being the case,i should ask as to why i am able to get a voltage out of the coil that is sitting 3/4 of an inch away from the toroid coil?.We can see(other than the phase shift due to high frequency)that it seems to be coupled to the pulsed input> Now this is an AC input,but i dont see that makeing a difference?.
If the fields are contained within the core,i should get nothing in the way of voltage in the secondary coil?.

A test thought.
If i take a standard toroid coil(non magnetised core)and place a magnet above the center,when applying a dc current to the toroid coil,the magnet above should have less attraction due to core saturation?. If i get a stronger pull on the PM when a dc current is applied,this could only mean an eminating magnetic field-correct?.
Just trying to think how we could test to see if there is an eminating magnetic field from the toroid.