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Author Topic: On the notion of a magnetic motor  (Read 22827 times)
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Not at present however, tangential induction does use the sides of PMs to induce a coil.  The mmf is mostly uni-polar in this case and useful for potential OU which is what my research has focused on for quite some time.

I understand and agree however, the position of the PM is this particular test was such that I tried to eliminate this rotated vector.  IOW, the end of each N and S pole did not protrude beyond the outside of the coil bobbin.  To be clear, the coil assembly was held inside each pole. Referencing your vector diagram in your post #57, the high aspect ratio PM (width verses thickness) indicates the parallel vectors to be rather uniformly straight.  In my test I purposely used a low aspect ratio PM assembly and with the positional limit mentioned above, we could assume the horizontal vectors should be only slightly rotated or not at all in the field of induction.

In ref to the wire position on the center of the PM and it's attraction force, it could also be caused by the action seen in my crude drawing below from the converging flux from each pole.

Regards,
Pm


Edit: Added italicized.

Sorry Pm, I don't follow your logic about the vectors in the diagram, attached again. I also have difficulty comprehending your test.

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In ref to the wire position on the center of the PM and it's attraction force, it could also be caused by the action seen in my crude drawing below from the converging flux from each pole.

Not if you believe in Lorentz force law.
bi
   
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In ref to the wire position on the center of the PM and it's attraction force, it could also be caused by the action seen in my crude drawing below from the converging flux from each pole.

...

PM,

If the field is as you have drawn it in your "Wire to PM.png", why does a hall probe slid from one end of the magnet to the other, with its measurement axis parallel to the magnetic axis, not detect any field nulls or polarity reversals as was noted in my previous post?

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Sorry Pm, I don't follow your logic about the vectors in the diagram, attached again. I also have difficulty comprehending your test.

Not if you believe in Lorentz force law.
bi

Bi,

Look at the relative comparison between your vector diagram and my best guess vector diagram.  My diagram is drawn 2x accurately.  The center positions of the cores represent the center and outside positions plus of each core placement during the PM sweep.  The spacing away from the PM is also shown.  I hope this is clear enough.

If my best guess of the field vector is close, do you think it would justify the difference in induced currents seen in the test?

Edit: OOps! Forgot to post the pix!

Regards,
Pm
   
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PM,

If the field is as you have drawn it in your "Wire to PM.png", why does a hall probe slid from one end of the magnet to the other, with its measurement axis parallel to the magnetic axis, not detect any field nulls or polarity reversals as was noted in my previous post?

PW

PW,

I do have a hall effect device somewhere and once I find it, I will do a test on my actual setup when found.

Regards,

Pm
   
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PW,

OK, I found my linear hall sensor HAL400 which is sensitive to the flux passing through the center of the SOT-89A package.  When used in this manner, I see no flux change at the center of the stacked PM I used when spaced .50" away from the outside of the PM!!  This leaves me curious about the induction tests I ran.  At this point in time, I have no answer!

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Pm
   
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Bi,

Look at the relative comparison between your vector diagram and my best guess vector diagram.  My diagram is drawn 2x accurately.  The center positions of the cores represent the center and outside positions plus of each core placement during the PM sweep.  The spacing away from the PM is also shown.  I hope this is clear enough.

If my best guess of the field vector is close, do you think it would justify the difference in induced currents seen in the test?

Edit: OOps! Forgot to post the pix!

Regards,
Pm

Yes Pm, I do. Thanks for posting the clearer diagram.

It is unknown how the ferromagnetic core distorts the field of the magnet as Tinman noted, but I imagine it would be like a mirror image about the midline.

Also, if you get your Hall effect device working, please attempt to verify field shape as depicted in reply #58.
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PW,

OK, I found my linear hall sensor HAL400 which is sensitive to the flux passing through the center of the SOT-89A package.  When used in this manner, I see no flux change at the center of the stacked PM I used when spaced .50" away from the outside of the PM!!  This leaves me curious about the induction tests I ran.  At this point in time, I have no answer!

Regards,
Pm

PM,

The mapping I have performed using the Hall sensor on my gaussmeter appears to indicate that the field geometry is as it has always been traditionally depicted (i.e., as bistander has been depicting and simulating all along).  It also appears to rule out the idea of having two separate (and opposite?) poles at opposing ends with a null of some kind in the center. 

Anyone with a gaussmeter or Hall sensor can confirm these observations.  I also recommend a piece of color changing viewing film to visualize the "apparent" null/bloch wall that appears with viewing film and ferrocells so that area in particular can be measured with the Hall sensor.

(I really like the color changing viewing film.  It clears itself instantly when the magnet is removed, without leaving remnant smudges as often happens with the green stuff.  The ones I have came laminated in fairly rigid plastic with a nice case to boot...)

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PM,

The mapping I have performed using the Hall sensor on my gaussmeter appears to indicate that the field geometry is as it has always been traditionally depicted (i.e., as bistander has been depicting and simulating all along).  It also appears to rule out the idea of having two separate (and opposite?) poles at opposing ends with a null of some kind in the center. 

Anyone with a gaussmeter or Hall sensor can confirm these observations.  I also recommend a piece of color changing viewing film to visualize the "apparent" null/bloch wall that appears with viewing film and ferrocells so that area in particular can be measured with the Hall sensor.

(I really like the color changing viewing film.  It clears itself instantly when the magnet is removed, without leaving remnant smudges as often happens with the green stuff.  The ones I have came laminated in fairly rigid plastic with a nice case to boot...)

PW

The fact that your hall sensor works, should tell you that two different fields, or field gradients exist on either side of the hall sensor.
If there was just one single field on both sides of the hall sensor, that were equal in magnitude (as claimed), it would not work, due to the electrons not being deviated from their straight path through the conductive junction material within the sensor. The hall sensor works using the Lorentz force, and with the same field either side of the hall sensor, there is no Lorentz force to curve the path of the electrons for the sensor to work. This is exactly the same as the homopolar generator, where if you have a north field either side of the rotating disk, then no current would flow through the disk, and around the circuit. You must have a north field on one side of the disk, and the south field on the other side of the disk, in order for current to flow through the disk when it is rotated.

Everything has an equal and opposite, and the magnetic field is no different. It must also have an equal and opposite charge.
Like charges repel, and unlike charges attract= the PM fields.
If the PM field was flowing out from the north and into the south as shown by the arrows in the field depiction, then that would explain as to why two north poles would repel, but not why the two south poles would. If this flow of (what ever it is) was flowing in at the south poles, then it would be like bringing two vacuum cleaner hoses close together--they would draw each other in.

What ever is flowing, or what ever is causing the magnetic force, must be two different/opposite fields of charge of some sort, in order for like poles to repel, and unlike poles to attract.
If it were the same field, then both ends of both magnets would repel each other, just like any other 2 charged bodies would, when charged with the same polarity.


Brad


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I have been following this with some interest .

One of my recent uses of hall sensors was to make a tacho pickup on a 25hp 2 stroke motor.

There are a few different kinds of hall sensors that could create confusion .
Some act only on one pole and some act on both poles.

The first pickup I made was with a dual pole type and gave a plus and a minus pulse every time the magnet passed the hall device .

As soon as I replaced it with a monopole hall sensor I got the single pulse I needed.

This may, or may not be a source of confusion in this case , but the potential for misunderstanding of different hall sensor types is present.
   
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The fact that your hall sensor works, should tell you that two different fields, or field gradients exist on either side of the hall sensor.{\

I do not believe a gradient is required for a Hall effect probe to function.  However, no change in field strength or polarity is detected as the probe is moved along the side of the magnet with its detection axis parallel to the magnetic axis.  If there was an extra or opposite pole at each end with a null in the middle, surely this would create even greater gradients that can be detected.  As previously stated, even moving the probe through an area that appears to be a null or bloch wall when observed with viewing film, no such null or any polarity reversal is detected with a Hall probe.  A piece of viewing film and a gaussmeter (Hall probe) will allow you to confirm this for yourself.   

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If there was just one single field on both sides of the hall sensor, that were equal in magnitude (as claimed), it would not work, due to the electrons not being deviated from their straight path through the conductive junction material within the sensor. The hall sensor works using the Lorentz force, and with the same field either side of the hall sensor, there is no Lorentz force to curve the path of the electrons for the sensor to work.  This is exactly the same as the homopolar generator, where if you have a north field either side of the rotating disk, then no current would flow through the disk, and around the circuit. You must have a north field on one side of the disk, and the south field on the other side of the disk, in order for current to flow through the disk when it is rotated.

I will give you comment above further thought, but I do not believe, as you state, that a magnetic gradient is required for electron deflection in the Hall probe.  Keep in mind that a Hall probe has a bias current that flows through one axis of a planar conductor with the detection axis perpendicular to that current flow. The Lorentz force is between the magnetic field and the bias current.

As well, I suspect a homopolar generator/motor would also function with just one pole of a magnet facing the homopolar disc and the other pole directed away using a long magnetic armature, but that is another topic for discussion.

For now let's stick to whether the field around a PM is as you propose or as it is conventionally envisioned. 

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Everything has an equal and opposite, and the magnetic field is no different. It must also have an equal and opposite charge.

The equal but opposite regarding a PM are its vectors.  With regard to a PM, I would not use the word "charge".   

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Like charges repel, and unlike charges attract= the PM fields.

Are you equating electrical charges to the poles of a PM?  I would not. 

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If the PM field was flowing out from the north and into the south as shown by the arrows in the field depiction, then that would explain as to why two north poles would repel, but not why the two south poles would. If this flow of (what ever it is) was flowing in at the south poles, then it would be like bringing two vacuum cleaner hoses close together--they would draw each other in.

The arrows do not indicate "flow",  They are merely vectors (although I have seen some seemingly use the vectors to indicate "flow", I would not).  The bigger clue is which way are electrons deflected at opposing poles...

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What ever is flowing, or what ever is causing the magnetic force, must be two different/opposite fields of charge of some sort, in order for like poles to repel, and unlike poles to attract.
If it were the same field, then both ends of both magnets would repel each other, just like any other 2 charged bodies would, when charged with the same polarity.

I myself would be inclined to not use words like "flow" or "flowing" when describing a PM.

The fields at the poles are indeed opposite but only in that the vectors point outward and inward at opposite ends of the magnet.  Again, they are merely vectors, they do not indicate "flow" or motion.  As in my first post, the Hall probe demonstrates which way electrons are deflected, and, as in that post, if one could see through the face of the magnet to the opposing face, we would see that the electrons are deflected in the same direction at each pole, when viewed from one end through the magnet to the opposite pole.  Similar to my solid bar rotating on its long axis analogy, the ends of the bar rotate together in the same direction, yet when observed at one end or the other they appear to be rotating CW or CCW based upon which end is viewed. This is just an analogy, not to be taken literally... 

In an earlier post you stated:

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I believe that the PM is separating charges of an extremely dense energy field that is all around us, and of which we are yet to understand.
 

Except for the words "separating charges" this statement is very close to that which I also believe to be true.

However, I disagree with your idea of two separate and opposite poles at opposing ends of a magnet with some sort of null in the middle.  I also believe the jury is still out with regard to whether the field rotates with the magnet.  Personally, I believe it does (this has been a debate between scientists for many years).

While I will agree that scientists don't know everything, they do know quite a lot with regard to the geometry of magnetic fields.  Look what they are able to accomplish with computer simulations and reductions to practice regarding Tokamaks and Stellerators, MRI machines or highly efficient PM motors.  A new theory regarding what a magnetic field actually "is" will embrace and enhance our current understanding and explain why the fields are shaped and behave as they do.  It won't prove all the scientists' observations wrong, it will explain them in a new light. 

PW
« Last Edit: 2024-05-12, 12:57:53 by picowatt »
   

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author=picowatt link=topic=4661.msg112099#msg112099 date=1715487478



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I do not believe a gradient is required for a Hall effect probe to function.  However, no change in field strength or polarity is detected as the probe is moved along the side of the magnet with its detection axis parallel to the magnetic axis.  If there was an extra or opposite pole at each end with a null in the middle, surely this would create even greater gradients that can be detected.  As previously stated, even moving the probe through an area that appears to be a null or bloch wall when observed with viewing film, no such null or any polarity reversal is detected with a Hall probe.

Why would you detect a neutral point using a hall probe along the magnets length, when the field gradient remains the same value along the length of the magnet?
So doing my best to explain, we need to view the field as a cloud of !charged! particles, where one end of the magnet has a negative net charge, and the other a positive net charge. (i will get to the type of charge in one of your later responses). So looking at my first scribble below, where it is only 2 dimensional, (but should be viewed a 3 dimensional), we can see that when the hall probe is slid from one end to the other, the same field gradient value exists along the length of the magnet that the hall probe would encounter, resulting in your hall probe showing the same result all along the magnets length.

Now, the second diagram shows the same thing, but this time using a voltage dropped across a resistive carbon rod.
With the two DMM probes fixed, so as the same distance between the probes is maintained, such as the junction in the hall probe is, regardless of the fact that we both know that one end of the carbon rod has a net positive charge, and the other a net negative charge, the DMM will read the same voltage at any two fixed points along that resistive rod.
Now, if we use a ferromagnetic rod, like that used for the core of a coil, at the center of the magnet, the rod would see an even negative and positive value, which means a net value of 0.
If this coil core is move to the left, it would see a net positive value, and if moved to the right, it would see a net negative value, which is why we would get opposite sines from right to left of center, and a 0 value emf at the center position.

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As well, I suspect a homopolar generator/motor would also function with just one pole of a magnet facing the homopolar disc and the other pole directed away using a long magnetic armature, but that is another topic for discussion.

Yes it will work with just one magnet on one side of the disk, but the field gradient is still their through the disk.
By placing another magnet on the opposite side of the disk, with the two opposite fields facing the disk, far more current, and a higher voltage is produced, as the disk now sees a far greater field gradient.

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For now let's stick to whether the field around a PM is as you propose or as it is conventionally envisioned.

I would ask, who decided the field convention? and what instruments were used back then to conclude such a convention?
What is the magnetic force?. What is it made of?
The conventional magnetic field theory does not answer this fundamental question.

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The equal but opposite regarding a PM are its vectors.  With regard to a PM, I would not use the word "charge".

The vectors and field lines are man made constructs, in the hope of describing what a magnetic field is.
In reality, the fields should be viewed like clouds of charge, where the charge density is greatest at each pole.

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Are you equating electrical charges to the poles of a PM?  I would not.

I am guessing you have not read the whole thread, where i explain as to what type of charges i believe they are, which is not the conventional electric charge as we know it.
I believe the PM is separating some other kind of charge that exists within an energy field that exists in all space.
Perhaps this dark energy they speak of, or vacuum energy, or the Aether.

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The arrows do not indicate "flow",  They are merely vectors (although I have seen some seemingly use the vectors to indicate "flow", I would not).  The bigger clue is which way are electrons deflected at opposing poles...

I would agree that there is no flow of anything, but only a separation of some kind of charge.
If nothing is flowing or moving, what is it that is deflecting the electrons?
In order for an electron to be deflected, energy is required. Where or what is this energy if nothing is flowing or moving?
We know that photons, although massless, can move an electron, as they (the photon) have energy due to motion.
So what moves or deflects electrons in a magnetic field?

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I myself would be inclined to not use words like "flow" or "flowing" when describing a PM.

Neither would i, but many people do.
So once again, where does the magnetic field get it's energy from to deflect an electron, which has mass?

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The fields at the poles are indeed opposite but only in that the vectors point in opposite directions at each end.

If there is no flow or motion, what are these !vectors!?
What do the arrows (vectors) show?, if nothing is moving.
At the north, we have the arrows pointing out of the magnet body, and the south end, we have the arrows pointing into the magnet body.
If nothing is exiting or entering the magnet (no flow), then what exactly do these vector arrows show?

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Again, they are merely vectors, they do not indicate "flow" or motion.

So if the field is static, then how can there be a direction associated with the vectors?
How is it that although the same static field (nothing flowing) exists at each end of a magnet, we can say-well one end the field is pointing in, and the other it is pointing out.

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As in my first post, the Hall probe demonstrates which way electrons are deflected,

Where is the energy coming from to deflect the electrons?

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if one could see through the face of the magnet to the opposing face, we would see that the electrons are deflected in the same direction at each pole,

Which would mean that one end would have a negative charge, and the other a positive charge.

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However, I disagree with your idea of two separate and opposite poles at opposing ends of a magnet with some sort of null in the middle.

Everything i have shown, shows a neutral point at the center of the poles of a magnet, along with many others here.
My 2 field theory explains exactly why you see what you see with your hall sensor.
It explains as to why opposite poles attract, and like poles repel.
It explains why a piece of ferromagnetic material will not stick to the center portion of the magnet between the poles.
And it explains why passing the center point of a magnet pass the core of a coil will not induce an emf across that coil.
You claim that your hall sensor shows the same field along the length of the magnet, and so it should produce an emf across a coil when any portion of that magnet is passed across the core of the coil-but it does not.

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  I also believe the jury is still out with regard to whether the field rotates with the magnet.  Personally, I believe it does

If that were the case, we could spin either the disk or the magnet in a homopolar generator, to generate a current flow through the disk.
But this is not the case. We can spin the magnet as fast as we like, but no emf would appear across the disk, and no current will flow through the disk, as no charge separation takes place.
This can only mean that the magnetic fields are pinned to the surrounding space of the magnet body, and is not part of the magnet body it self.
In order to generate current flow through the disk, there must be relative motion between the magnets fields, and the copper disk.
So, if the magnetic fields actually moved with the magnet body, then would could just spin the magnet to get that relative motion between the magnetic fields, and the disk.
This would mean we could pull electrical energy from the disk, without having to use brushes and the likes to collect that electrical energy.
We could solder one wire to the outer rim of the disk, and the other to the center of the disk, and just spin the magnet=a pure DC brushless generator and motor would be had.
But as i am sure you are well aware, this does not work.

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While I will agree that scientists don't know everything, they do know quite a lot with regard to the geometry of magnetic fields.  Look what they are able to accomplish with computer simulations and reductions to practice regarding Tokamaks and Stellerators, MRI machines or highly efficient PM motors.  A new theory regarding what a magnetic field actually "is" will embrace and enhance our current understanding and explain why the fields are shaped and behave as they do.  It won't prove all the scientists' observations wrong, it will explain them in a new light.

The 2 field theory changes nothing about the workings of any magnetic device.
But what it does do, is explain what the magnetic field is, what the magnetic force is, and why like poles repel, and unlike poles attract.

I mean, you really just have to stand back and look at all the effects we see with magnetic fields, where the two field theory explains them all.
Think about what happens when say a piece of neodymium is magnetized.
We zap it with a strong electromagnetic field- all the electrons (well most) are deflected in the same direction, and then all of a sudden, we have this invisible !force field! just appear out of no where.
I say force field, as this invisible field can apply a force to another such invisible field.
Where did this force field come from if nothing flows out of, or into the PM?

I stand by my claim.
That field already existed around that PM body before it was magnetized, in a neutral state, as it does in all space. It never just spewed out of the magnet once it was magnetized.
Once all those little generators (electrons) were all working together( material magnetized), then caused the separation of charges that already existed in a neutral field around the PM body.
There is nothing that the two field theory does not work for, and it explains what the magnetic field is, and how and why it can exert this invisible force.


Brad


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The 2 field theory changes nothing about the workings of any magnetic device.
But what it does do, is explain what the magnetic field is, what the magnetic force is, and why like poles repel, and unlike poles attract.

I would agree your on the right track.

I noticed when speaking with many scientific minded people that they have a few blind spots. I can explain how there are over a billion trillion stars which have been radiating ungodly amounts of EM energy out into all space for billions of years but it doesn't register in there mind. They get this blank stare and glassy eyes ie. cognitive dissonance and won't acknowledge the fact that all space is full of energy. They talk like this EM energy just magically dissipated into nothing and space is empty however we know this cannot be true. I think this helps explain why so little progress has been made in understanding what the Primary Fields are.

My theories tend to align more with yours in that there could be no such thing as a "magnetic field". The supposed magnetic field is simply what happens when motional electric fields interact with external EM energy. As such the magnetic field is not something in itself more so an interaction with something else in the surrounding space. Which fits well with the fact that no fields rotate on axis. Fields do not rotate for the same reasons light radiated from a bulb does not rotate.

In effect, you could be correct and there are two different fields having two different polarization's. Now were talking about something similar to wave theory. Could like field repulsion and unlike field attraction relate to constructive and destructive interference?. So like field repulsion could be due constructive interference increasing the wave amplitude/field density. Like wise unlike field attraction could be due to destructive interference decreasing the wave amplitude field density due to cancellation/neutralization.

This seems like a much more rational or coherent explanation rather than a spooky action at a distance acting through nothing. As well, if all space is actually full of EM energy then we don't have to wonder where the energy for a FE device comes from, everything gets easier.

AC





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Brad,

A gradient in the B field is not required for the Hall effect.  A steady state and homogeneous B field in the Z axis, vector pointing upward, will cause electrons flowing in the Y axis to deflect to the left (right hand rule) in the X axis.  Again, no "gradient" required...

The vectors indicated in a magnetic field representation basically only tells you which way electrons (or other charged particles) will be deflected when passing through a given point in the field (using right hand rule).  That is all the vectors indicate. 

Using a Hall sensor to study the field shape seems to be the least intrusive way to probe the conditions at any given point in the field.

PW   
« Last Edit: 2024-05-12, 17:56:05 by picowatt »
   
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So if the field is static, then how can there be a direction associated with the vectors?
How is it that although the same static field (nothing flowing) exists at each end of a magnet, we can say-well one end the field is pointing in, and the other it is pointing out.

I never said the field around a PM was "static", I said the vectors do not indicate "flow", as such...

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You claim that your hall sensor shows the same field along the length of the magnet, and so it should produce an emf across a coil when any portion of that magnet is passed across the core of the coil-but it does not.

No it should not produce an EMF.  As I previously stated, induction only occurs when the magnetic field is changing .  Moving your center coil (in the three coil drawing) slightly to the left and right exposes the coil to similar, mostly unchanging, magnetic conditions in both positions, hence little induction occurs.

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The 2 field theory changes nothing about the workings of any magnetic device.
But what it does do, is explain what the magnetic field is, what the magnetic force is, and why like poles repel, and unlike poles attract.

Actually I would think that it would change quite a bit.  For one, it would change how charged particles react to a PM's magnetic field.

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I stand by my claim.  That field already existed around that PM body before it was magnetized, in a neutral state, as it does in all space.

On this we both agree...
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Brad,

Please explain the "FIELD GRADIENT.JPG" and the "CARBON ROD TEST.JPG" in your previous post.  What is it you are depicting?

Thanks,
PW
   
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I never said the field around a PM was "static", I said the vectors do not indicate "flow", as such...

No it should not produce an EMF.  As I previously stated, induction only occurs when the magnetic field is changing .  Moving your center coil (in the three coil drawing) slightly to the left and right exposes the coil to similar, mostly unchanging, magnetic conditions in both positions, hence little induction occurs.

PW, I may be misunderstanding you here but in that drawing the idea isn't to move the coil to the left or right against the fixed PM, it is to move the coil say left, then move the PM in or out of the page.  Then move the coil to the center and again move the PM in or out of the page, etc.  This action produces the waveforms I show in my post #71 when the PM assembly is moved in the same direction for each test.

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Actually I would think that it would change quite a bit.  For one, it would change how charged particles react to a PM's magnetic field.

On this we both agree...
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PW, I may be misunderstanding you here but in that drawing the idea isn't to move the coil to the left or right against the fixed PM, it is to move the coil say left, then move the PM in or out of the page.  Then move the coil to the center and again move the PM in or out of the page, etc.  This action produces the waveforms I show in my post #71 when the PM assembly is moved in the same direction for each test.

That's not the way I understood it. My understanding was motion was parallel to the magnetic axis and believe I mentioned that.
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Brad,

Please explain the "FIELD GRADIENT.JPG" and the "CARBON ROD TEST.JPG" in your previous post.  What is it you are depicting?

Thanks,
PW

Ok, the field gradient change JPG is the transition change from a positive to negatively charged field.
The fields around the PM start as very dense at the poles, and slowly decrease toward the other pole, where the center of the magnet is not void of the fields, but where the two fields are of equal density, thus creating a neutral field value.

The carbon rod JPG
In your comments about using the hall probe, you stated that you seen no field change along the length of the magnet, and that the field exists along the length of the magnet.
The carbon rod JPG also would show no voltage differential or change on the DMM, at any point you placed the two DMM probes, (which have a fixed distance between them) at any point along the carbon resistor rod, even though we know that the + end has a net positive charge, and the - end has a net negative charge, due to the charge gradient being the same along the length of the resistive rod.
Your hall sensor is working in much the same way, where although the ends of the magnet have a net field, the field gradients along the length of the magnet remain the same.


Brad


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That's not the way I understood it. My understanding was motion was parallel to the magnetic axis and believe I mentioned that.
bi

Then you mis-understood.
I clearly stated that the magnet is passed across the coil core, not slid along the coil core.
See reply 50.


Brad
« Last Edit: 2024-05-13, 03:42:01 by TinMan »


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author=picowatt link=topic=4661.msg112104#msg112104 date=1715530475


Quote
I never said the field around a PM was "static", I said the vectors do not indicate "flow", as such...

If it is not flowing or moving, is that not a static condition?

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No it should not produce an EMF.  As I previously stated, induction only occurs when the magnetic field is changing.

The magnetic field is changing in relation to the coil core, when the magnet is waved across the coils core.
You stated that along the length of the magnet, your hall probe detected no change in the field along the length of the magnet.
So, if we wave the magnet passed the coil core, where we use all three positions as indicated in my 3 coil JPG, then all 3 coils should produce the same sine.
But we do not see that. We see opposite sines for both the left and right coils, and no sine(emf) at all across the center coil position.

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induction only occurs when the magnetic field is changing

No, there only needs to be relative motion between the fields and the inductor for induction to take place, not a changing field.

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Moving your center coil (in the three coil drawing) slightly to the left and right exposes the coil to similar, mostly unchanging, magnetic conditions in both positions, hence little induction occurs.

As stated in the relevant post, the magnet is passed across the core of the coils, not slid from side to side.

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Actually I would think that it would change quite a bit.  For one, it would change how charged particles react to a PM's magnetic field.

I don't see how.
The charged particles could either be pushed in one direction by one field, or pulled in the same direction by the other field.
Much the same as we can move any object. We can either push from one side, or pull from the other side, to get that object to move in the same direction.

Quote
On this we both agree...

Ok, great. We both agree that the field already existed around the PM in a neutral state.
So once the PM body was magnetized, what took place within that existing field that was around the PM body, that was in a neutral state?
You would have to agree that some form of organization of that field took place?
What kind of organization could have taken place, where now 1 part of this organized field can now repel the same organized part of a similar field, and where that organized field can attract the opposite part of a similar organized field?

I believe that there are those-black opp type organizations, that have worked out how to manipulate this field of energy that exists in all space.
I believe they know how to draw energy from it, and how to cause an imbalance in it to provide propulsion.

The humble PM organizes this field, and can produce an invisible force, by arranging the electrons in a way that they all work together, and organize this field.
We also know that we can achieve the same field organization by getting those electrons to travel altogether in the same direction through a conductor, so both are related to getting the electrons to work together, and organize this field of what ever it is.


Brad


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PW,

OK, I found my linear hall sensor HAL400 which is sensitive to the flux passing through the center of the SOT-89A package.  When used in this manner, I see no flux change at the center of the stacked PM I used when spaced .50" away from the outside of the PM!!  This leaves me curious about the induction tests I ran.  At this point in time, I have no answer!

Regards,
Pm

Hi PM

I wonder what would happen if you set up a simple reed switch circuit, where you would have a battery or power supply, an LED, and the reed switch, and moved that reed switch along the length of stacked magnet? Would the reed switch open, causing the LED to go out, when it got to the center of the stacked magnets?, which would indicate no net field at the center of the magnet stack-or single magnet if you have a long bar or rod magnet.

I would try it my self, but i am 1000Km from home, on vacation.
Do you have a reed switch to carry out such an experiment?


Brad


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It's not as complicated as it may seem...
I am pretty sure that any civil conversations would not be deleted.

So, looking at the diagram below that i just threw together, we can see what the result would be if the long rod/bar magnet was passed across the cores of each 3 coils in their relative position.
How exactly can this happen if the field is the same all around the magnet, and where the B field is the same passing all 3 cores of the coil?
The arrow of the B field depicts that the B field is the same along the length of the magnet, and will cut through each of the 3 cores in the same direction, and yet the left and right coils have opposite sines, and the center coil produces no emf at all.

Now, replace this single field theory with the one i believe to be correct, and what would the scope show?  O0


Brad

The net induced voltage in the centre coil is nil because the positive-induced and negative-induced voltages are simultaneous, equal in amplitude, but in opposite polarity, and therefore they cancel each other out.

The two outside coils however experience an imbalanced positive and negative induced voltage, and therefore the net induced voltage in each case is non-zero, and opposite in polarity to each other.

- There is no null zone in the middle of a magnet.
- Maximum induced voltage is achieved by aligning the magnet axis and coil core axis end-to-end
- Minimum induced voltage is achieved by aligning the magnet and coil core axis as per your middle coil's configuration (perpendicular and in the middle)


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Then you mis-understood.
I clearly stated that the magnet is passed across the coil core, not slid along the coil core.
.


Brad

Hi Brad,

That's still not clear.

Faraday's Law. Notice cosθ. This term takes voltage to zero when motion is parallel to B.

Simple as that.
bi

It should have been clear that I was talking about motion parallel to the axis as is the B vector at the middle of the magnet and shown by diagrams I posted numerous times.

Also, my reply#73:

Quote
Hi Pm,

Remember
I am talking about this:
https://youtu.be/F2JFDpTE_ls?si=HRzgcA1K0LYBxUD9


These coils (with cores) are a different situation. You're looking at Faraday's Law instead of Lorentz.

But still, I contend at the middle of side of the magnet, the external field is strong and parallel to the magnetic axis. Motion of a conductor parallel to the B vector causes cosθ to equal zero so induced voltage is zero per Faraday's Law. Displacement from the midpoint, either way, introduces a perpendicular component to the B field and will increase cosθ so induced voltage appears in a conductor moving parallel to the axis.

You don't see generators using the sides of magnets.

In the experiment to which I've been using, the current carrying wire, once having moved and positioned midway along the side, comes to rest and continues to experience a strong force against the body of the magnet. This demonstrates a strong presence of magnetic field parallel to the axis.
bi

I was clear about my interpretation of the moving coil experiment.

BTW, I was experimenting this evening with the magnet, wire and coil which I showed previously. By using a stronger current the wire, or coil side could pick the magnet up 3-4 inches vertically off the table then suspend it against the middle of the magnet side. I think that demonstrates there is a strong magnetic field parallel to the axis along side of the magnet.
bi

edit: I see poynt99 posted while I was composing. I agree with his statements. Thanks.
   
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Ok, the field gradient change JPG is the transition change from a positive to negatively charged field.
The fields around the PM start as very dense at the poles, and slowly decrease toward the other pole, where the center of the magnet is not void of the fields, but where the two fields are of equal density, thus creating a neutral field value.

I must admit, your field gradient drawing and the explanation above leaves me more confused than ever as to what it is you envision going on in and around a PM.  Are you still adhering to the ideas of orbital alignment and domains within the PM?  You reference "+/- charges", are you referring to electrical charges?

If you were to draw vectors and field lines around the magnet in the gradient.jpg, what would they look like?

PW
   

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author=poynt99 link=topic=4661.msg112113#msg112113 date=1715568631

Quote
The net induced voltage in the centre coil is nil because the positive-induced and negative-induced voltages are simultaneous, equal in amplitude, but in opposite polarity, and therefore they cancel each other out.

The two outside coils however experience an imbalanced positive and negative induced voltage, and therefore the net induced voltage in each case is non-zero, and opposite in polarity to each other.

- There is no null zone in the middle of a magnet.
- Maximum induced voltage is achieved by aligning the magnet axis and coil core axis end-to-end
- Minimum induced voltage is achieved by aligning the magnet and coil core axis as per your middle coil's configuration (perpendicular and in the middle)

That is absolutely correct.
There is no null zone as others have said, but there is a neutral zone as i have stated, where the field gradient is both equal and opposite that induces the core at the center of the magnet, which results in no efm being produced across the coil.


Brad


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