Hi Len,

RE: Measuring it with a meter may be inconclusive as the surface may be non conducting, ie. it may have an oxide or other type of film.

You've hit the nail on the head again. I've been on my magnet suppliers website and they reveal this:

"Our Neodymium-Iron-Boron magnets are approximately 75 iron, and have a surface protector to prevent corrosion"

The iron in the magnets construction suggests saturation problems

In respect to your suggestion, Another way to do it would be to use a ferrite core and a DC current superimposed on the AC current to provide the "DC field" with the AC imposed on it, ie. don't use the magnet

Do I take it that a ferrite core is preferable to the neo-magnet then, or could I just use a strong ferrite magnet within the inductor? Maybe it's back to the drawing board, Len.

As explained to Hero999 in my previous post, my main aim was to superimpose and add the circuits varying pulsed output upon the magnets very impressive static gauss of 10000, thus giving a larger overall field strength. This would hopefully give me a larger depth of magnetic penetration into biological materials.

Kind regards as usual,

John

 

John,
As I said above, I'm not an expert in magnetics. So I suggest to glean as much as you can from the manufacturer's web sites and the internet in general.

Perhaps you could start another thread in this forum asking for advice on the properties of ferrite.

__________________
Len

 

Hi Len,

Your response is impressive and factual from my limited knowledge. I'm far from an expert in any field and thus I'm at the mercy of those who freely choose to impart their knowledge to me. Of this I'm truly grateful. My aim, as previously stated, is to acheive as maximum a penetration of biological materials as possible, in as great an alternating + varying field strength & frequency as possible, within what I believed was achieveable via my origininal concept of static field (neo magnetic inductor) + that of the added and created pulsed fields from the circuitry. I must convey honestly that I'm not the most adept or able person to impart my ideas and concepts to others, but I do hope I can achieve such a realisation of my intents in my somewhat naive way via you and friends on this forum.

In my minds eye I visualise the reality of adding something to that which already exists, i.e. neo-magnetic gauss + ?, but cannot claim any expertise in that area of static magnetics + a pulsed electronic content.

Likewise I cannot make any claims to my beliefs or visualisations of this concept because I don't possess that expertise in any capacity.

Len, on this basis, and from your electronic experience, do you believe, without predjudice of course, that what I'm aiming to achieve with my revealed concept is viable with just a strong alternating field as you suggest?

RE: But I'm dubious about your claim that the static component will give you a deeper penetration.

For clarity, it's revealed that all static magnets have a known 'Magnetic Permiability depth' of all materials to varied extents. Therefore it seems reasonable to conclude that such a fixed content can be added too with the correct pulsed magnetic content via circuitry electronics. Once again, maybe I'm totally wrong in my inspired concepts. I personally make no claims.

I do relish and appreciate our communications and hope I don't outstay my welcome with my enthusiasm in this area.

Kind regards

John in the UK

 

Ooops,

Sorry Len, the last point went well over my head in my eagerness to achieve.

RE: Perhaps you could start another thread in this forum asking for advice on the properties of ferrite.

Yes, you are correct, I've probably exhausted everybody with my questions and I'm truly appreciative of their advice. I not one to impose upon those who have been so generous, and thank yourself and others for their contributions. Hopefully some day people will say of me as I aspire in knowledge, " I knew of him, and he helped me." A truly worthy acknowledgment.

Truly, thank you once more,

John in the UK

 

John,
I did not mean to imply that you stop adding to this thread.

What I meant is that the people who have the magnetic expertise may not necessarily be reading this one given the subject heading "Reasonance"

So if you start a thread with a subject line such as "Advice needed on ferrite materials" or something like that, you may attract the right audience.

I'll now go back to your previous post and answer it.

__________________
Len

 

The way you're proposing to do it will vary the strength of the static field.

So if the static field is much stronger than the alternating one, then it will be like a wave on the surface of deep water.

On the other hand, if you make the alternating field so strong that it overpowers the static field, and therefore causes the flux direction to alternate, then why have the static field?

For the sake of argument, let's assume that the saturation issue can be resolved.

If the static field is 10000 Gauss as you said and the alternating field has a peak of say 12000 Gauss (ie. when the magnet is not present), then the resultant field will change from a maximum of 2000 Gauss in one direction (ie. when the fields are opposing) to a maxiimum of 22000 Gauss in the other direction (ie. when the fields are adding).

So my question is - do you want a field that has a bias in one direction, or one that alternates from -12000 Gauss to +12000 Gauss?

I can't answer the question, but intuitively, I suspect that an unbiassed field would be better than a biassed one.

__________________
Len

 

Hi Len,

Sorry I got the wrong end of the stick in your previous reply. I mistakenly thought my topic was becoming too dominant on the forum, ie taking up too much time. As it's alien to my nature to intentionally impose upon people I reactively choose to 'ride into the sunset' with whatever knowledge I've been graciuosly offered. I certainly failed to realise that there are other more appropriate areas, and probably more relevant persons to ask about ferrites and magnetics. With that clarified I feel so much better. Anyhow;

RE: So my question is - do you want a field that has a bias in one direction, or one that alternates from -12000 Gauss to +12000 Gauss?

I'm truly not completely certain at this point, the higher gauss scenario seems very attractive as this follows my original concept of Static magnetic gauss + Circuitry created gauss = mega gauss.

However, your intuition seems to be leaning towards the -12000 to +12000 swinging choice and this leads me to ask whether this lower gauss level is achievable with just the electronic component alone. My limited knowledge of electronics forbids me from knowing the answer to that one. I am likewise asking myself whether I will achieve sufficient depth of penetration in a biological mass with a lower gauss level. These and similar questions have plagued researchers from the year dot so I don't feel alone here. I think the answer is to try one way and if the results are not the desired ones, try the other.

On the latter basis Len, which do you think is the easiest way to create a strong alternating magnetic field in the 12000 gauss area, and could such be made available at different frequencies? I ask this because biological material reacts and responds in sympathy to varied, plus specific frequencies, and strength of magnetic fields.

Quite a bundle of questions, maybe I should be paying you a consultancy fee. ( if only )

Any feedback, postive or otherwise, is very welcomed.

Cheers for now,

John in the UK

 

John,
Your post of a few days ago stated that the magnet produced 10000 Gauss.

So I chose 12000 Gauss for the flux to be produced by the coil as an example to illustrate what flux would be generated by the combination of magnet + coil, ie. the resultant flux would alternate between -2000 and +22000 Gauss.

Had I chose 30 kGauss, the flux would alternate between -20 kG and +40 kG.

Had I chosen 8 kG, the flux would alternate between +2 kG & +18 kG, ie. it would not reverse direction at any point in the cycle.

I'm just pulling figures out of the air without any real idea of what is practical in order to illustrate my point.

You need someone with more knowledge of magnetics to tell you how much flux a coil can produce.

I don't really have the time to dig out my physics books and revise what I once knew while doing my engineering degree.

So I suggest you start a new thread (with a suitable subject line) and ask for advice on how much flux can be produced from a coil.

But don't make the question too general. I suggest you state (in broad terms) how much flux you want to produce and how it will be directed into the patient.

From memory, the flux depends upon the current, the number of turns and the reluctance of the magnetic circuit.

The answer will also depend upon the frequency range you want to employ.

For high frequencies, you will need a low inductance coil; therefore, you will have to supply a high current to produce the flux.

At lower frequencies, you could use a coil with a higher inductance (ie. more turns) and therefore you will be able to produce the same flux with a lower current.

__________________
Len

 

Hi Len,

Thanks for your time and contributions to my conquest, they have most certainly opened up many new avenues of thought which I need to vigorously pursue if my goal is to be achieved and the rewards unselfishly reaped.

The link you sent to the Magnets and Electromagnets page was quite enlightening and useful too. I'm grateful for that.

In the future I will acknowledge your contributions, in whatever shape or form that will take, for without persons like yourself inspired ideas would remain just those, ' ideas', whereas now the seeds have been sown and the fruit is only a fraction away from picking.

Kindest regards and eternal gratitude,

Respectfully yours,

John in the UK

 

Hi,

In my internet search for information on Coils & Inductors I came across this website which has a beautiful Java calculator for working out a coils inductance / resistance / wire length req'd etc. Thought it might be useful to other forum members who wish to design such. Here's the link:

http://www.coilgun.info/mark2/inductorsim.htm

Regards to all,

John in the UK

PS. Hope I'm allowed to post this info in this section ??