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Author Topic: Coils,Magnetic and Electric fields  (Read 2334 times)
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After some discussion on the half coil syndrome thread about induced EMF,magnetic and electric fields in primary and secondary coil's,i would like to use this thread to discuss the topic more deeply.

First up-the big one.
Looking at the diagram below(i pinched you pic Smudge),what field from the primary coil causes the secondary coil(MOT) to produce a current flow through R1.?
Is it-1  :the B field cutting through the secondary from left to right,then right to left(as we are using AC)?.
Or 2    :The E field flowing radially around the secondary from the primary?.

Edit:-- You will notice that i have used B field in question one,and that is because i am referring to an air core type transformer in the above,as with an air core B=H.
« Last Edit: 2015-12-04, 22:58:35 by TinMan »
   

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Here is a good discussion of the E, H and B fields.  It also references a book I haven't found yet but will be looking for.  Hope this helps some.


http://electronics.stackexchange.com/questions/94744/what-is-the-difference-between-the-magnetic-h-field-and-the-b-field

Found the book.
Here is a link for the book recommended by author of the above discussion.


https://archive.org/details/magneticcircuit00karagoog




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After some discussion on the half coil syndrome thread about induced EMF,magnetic and electric fields in primary and secondary coil's,i would like to use this thread to discuss the topic more deeply.

First up-the big one.
Looking at the diagram below(i pinched you pic Smudge),what field from the primary coil causes the secondary coil(MOT) to produce a current flow through R1.?
Is it-1  :the B field cutting through the secondary from left to right,then right to left(as we are using AC)?.
Or 2    :The E field flowing radially around the secondary from the primary?.

Edit:-- You will notice that i have used B field in question one,and that is because i am referring to an air core type transformer in the above,as with an air core B=H.

It is answer 1 but with provisos.  It is the total AC flux that threads the coil which is (a) the flux flowing left or right through the primary minus (b) any of that flux that flows back in the opposite direction that passes through the secondary.  That total AC flux creates a circular E field at the secondary (which I did not show in my image, sorry about that) and that circular E field is what actually forces the conduction electrons along the wire.  As the secondary gets ever larger radius so more of the primary flux lines flow back through the secondary so the total threaded flux gets ever smaller.

Smudge
   
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It is answer 1 but with provisos.  It is the total AC flux that threads the coil which is (a) the flux flowing left or right through the primary minus (b) any of that flux that flows back in the opposite direction that passes through the secondary.  That total AC flux creates a circular E field at the secondary (which I did not show in my image, sorry about that) and that circular E field is what actually forces the conduction electrons along the wire.  As the secondary gets ever larger radius so more of the primary flux lines flow back through the secondary so the total threaded flux gets ever smaller.

Smudge

Thanks for joining in Smudge.
So,as i want to make everything very clear on this thread,i will go through what you said,so as i understand correctly.

Regarding our air core coil.
The alternating magnetic flux(lets use the top half of the sine first)flows through the center of the coil,and then loops back around the outside of the coil,and back into the center of the coil at the other end. At the bottom half of the sine,this flow direction is reversed. The magnetic flux that is looping back around the outside of the primary coil is what cuts the secondaries winding's(the MOT secondary in my case),and this creates an E field which gives rise to the EMF across that secondary-correct?.--If so,is this the case for all transformer action's,in that a magnetic flux must cut the windings of the secondary in order for an E field to be produced around that secondary,which gives rise to the EMF across that secondary?.

Brad.
   
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@Tinman

Good idea on this thread since it will enable lots of side discussions because as this subject matures, we will need it.

OK then let's take it step by step.

Before any discussion of "fields" let's first start with the actual AC on your air coil. Let's say the left side of the coil is connected to the AC hot and the right side is connected to AC neutral. We will designate them as Left and Right.

A scope sine wave if taken across the air coil while it runs and will show the peak rise and fall so when the sine wave.....

1) rises above the zero line,the left is still hot and the right is still the neutral side.
2) falls below the zero line, now which side is which. Let's be very very very clear on this question otherwise Tesla may come to us and clobber us on our heads. hahaha

So before going any further, this one question has to be resolved but one has to be very cognizant of the real impact of this one answer. So for point #2 which one is it? I have my own idea but one needs to hear this from those more qualified in the matter as being the presently accepted model.

Then as a side idea that may help you look at this "deeper" may is suggest the following that may sound crazy again but let's humor me a little. I always look for simple ways to integrate some variability into the research so........

Using your same set-up with the Tesla air coil and the MOT, Since the air coil is working in lengthwise, I would try to find two deflecting plates or large washers that can be held to the windings that are exposed on the left and right side of the MOT with maybe some type of padding in between so the metal plate does not touch the MOT windings. This will sort of deflect any air coil impress coming to the MOT from the sides and leave only the surface area of the inner winds exposed to the air coil influence. Then see if the scoped MOT is higher in the middle.

This is because we have to understand what we are using to make our differential claims. The MOT does not care from where its copper atoms notice a change, distant or not. Whatever is changing around the MOT will be evidenced in the MOTs scope shot as an average that produces peaks. So while you are dong this experiment, if you took a second pulsed coil and approached it to your MOT, the MOT will integrate this new source of atomic change into its averaged own output even it is it shown as high and low peaks, it is still averaged across the coil. It does not care where the change comes from but it needs to be shown to realize it is there.

Once #2 has been clearly established and accepted by all, then we can move forward. But the answer has to be clear, no ambiguity is permitted here because this is the most causal description of how AC works in a coil and from this point on can one only then analyze the proposed logic by only then integrating the effect of voltage and amperage. Start with the little stuff first.   

wattsup



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@Tinman

Good idea on this thread since it will enable lots of side discussions because as this subject matures, we will need it.

OK then let's take it step by step.

Before any discussion of "fields" let's first start with the actual AC on your air coil. Let's say the left side of the coil is connected to the AC hot and the right side is connected to AC neutral. We will designate them as Left and Right.

A scope sine wave if taken across the air coil while it runs and will show the peak rise and fall so when the sine wave.....


So before going any further, this one question has to be resolved but one has to be very cognizant of the real impact of this one answer. So for point #2 which one is it? I have my own idea but one needs to hear this from those more qualified in the matter as being the presently accepted model.

Then as a side idea that may help you look at this "deeper" may is suggest the following that may sound crazy again but let's humor me a little. I always look for simple ways to integrate some variability into the research so........



This is because we have to understand what we are using to make our differential claims. The MOT does not care from where its copper atoms notice a change, distant or not. Whatever is changing around the MOT will be evidenced in the MOTs scope shot as an average that produces peaks. So while you are dong this experiment, if you took a second pulsed coil and approached it to your MOT, the MOT will integrate this new source of atomic change into its averaged own output even it is it shown as high and low peaks, it is still averaged across the coil. It does not care where the change comes from but it needs to be shown to realize it is there.

Once #2 has been clearly established and accepted by all, then we can move forward. But the answer has to be clear, no ambiguity is permitted here because this is the most causal description of how AC works in a coil and from this point on can one only then analyze the proposed logic by only then integrating the effect of voltage and amperage. Start with the little stuff first.   

wattsup


Quote
1) rises above the zero line,the left is still hot and the right is still the neutral side.
2) falls below the zero line, now which side is which. Let's be very very very clear on this question otherwise Tesla may come to us and clobber us on our heads. hahaha

The so called 0 volt line is just a reference point-a point without potential.
It is from this point we can view in which direction the current is flowing. Your scope shows current flow direction in the sine,and the amount of force(pressure) that current is flowing at. It's not  above or below 0 volt's,it;s forward or backwards of current flow,as you cannot have less than 0 volt's.

You just have to take a stand alone generator to see this. Now you have no ground,but your scope will still show a sine across the potential of that generator. If you hold the output wires from that generator(not advisable)in your hands so as you have one wire in one hand,and the other wire in the other hand-one half of the sine will show you current flowing into your right hand and out of your left hand,and the other half of the sine will show you it is flowing into your left hand and out of your right hand.
Quote
Using your same set-up with the Tesla air coil and the MOT, Since the air coil is working in lengthwise, I would try to find two deflecting plates or large washers that can be held to the windings that are exposed on the left and right side of the MOT with maybe some type of padding in between so the metal plate does not touch the MOT windings. This will sort of deflect any air coil impress coming to the MOT from the sides and leave only the surface area of the inner winds exposed to the air coil influence. Then see if the scoped MOT is higher in the middle.

I would expect the MOT(secondary) to output more power through the load if a steel plate were placed either side of it,as the steel plate would draw in more of the radiant magnetic field around it that would normally not pass through it. So the magnetic fields now being attracted to the steel plates either side of the MOT must pass through the MOT,as the field will want to link-continue it's journey. So no,i dont think the steel plates will deflect the field,i think it will concentrate it.


Brad
   
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Test as per wattsup's description.
Long and boring for most,but it is interesting to see the difference the core makes when i slide it into the primary coil.


https://www.youtube.com/watch?v=gXLhJNdSnuo
   
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Test as per wattsup's description.
Long and boring for most,but it is interesting to see the difference the core makes when i slide it into the primary coil.
https://www.youtube.com/watch?v=gXLhJNdSnuo

What you observed is exactly as expected.  But before going into detail may I try to steer you away from what appears to me to be some incorrect perceptions.  You keep mentioning flux lines "cutting" the secondary which suggests to me that you believe the flux lines have to touch the conductor.  Wrong!!  It is the flux lines that don't touch the conductor that do the work, it is the flux lines that pass through the coil, with is why I used the term "threading".

You might ask how is it that flux that doesn't actually impinge on the conductor can create a voltage in it, and that requires a more detailed answer that goes into the realms of another type of field known as the vector magnetic potential which is given the symbol A.   In reality the current flowing in the primary coil, plus any atomic current circulations flowing in the core if it is present, create circular A field lines both within the coil and outside the coil.  Because the primary current is AC then so are these circular A fields, and the time rate of change of the A field then creates the circular E field that can drive electrons around a circular wire.  That A is now considered to be the primary field which then produces the magnetic B field that we are all familiar with.  The B field comes from the manner in which the A field changes spatially, and in particular how the A field changes value if you take an observation point by moving sideways from the field line.  There is a vector function of space known as the "Curl" that describes the spatial change in A needed to create B, and we end up with the formula B=Curl(A).   So current scientific philosiphy is that B comes from A, that E comes from a time-changing A, and therefore if you have that E there must also be a time-changing B present that is related to E.)

If you find all this confusing then just forget it and go back to the simpler viewpoint that it is the time changing B that produces circular E.  Those circular E lines exist within the B flux in the primary coil having zero value at the centre rising to a maximum at the inside edge of the coil.  Then outside the coil the value decreases as you move to ever larger radii.  For any given radius the value of E multiplied by the circumference gives you the volts-per-turn for a coil of that radius.  And that volts-per-turn is equal to the rate of change of total flux passing through the coil (not flux cutting or touching the conductor).  That is usually just the primary flux but for the coils you are playing with some of that primary flux can return through your large radius secondary so that the total flux gets reduced.  This effect would not be very noticeable with your very long primary coil because your secondary is quite close to the primary.  Only when your secondary is at a radius comparable to the primary coil length would you get any significant flux loss.

That brings me onto your video.  Without the core your "transformer" is a poor one (at 50Hz) because the primary inductance is not high enough.  The input is mainly resistive so the input current is in phase with the voltage (which you show at the end of your video).  That primary current creates flux, then since output voltage comes from rate-of-change of flux you get a secondary voltage that is almost 90 degree shifted from the primary voltage.  If you did any power measurements you would have an inefficient transformer.

With the core in place the primary inductance has increased so now it works much better as a transformer.  You find that primary and secondary voltage are almost in phase (or anti-phase depending on the polarity of the coil connections).   In that "good transformer" condition the flux that is creating the secondary voltage is the magnetizing flux that comes from the "magnetizing current" in the primary and that current is 90 degree shifted from primary voltage.  Electrically it does not represent a power flow from primary to secondary (although in the magnetic domain the magnetizing flux does represent power flow along the magnetic circuit).  With no load on the secondary the 90 degree shifted magnetizing current is the only current flowing (that ignores primary coil loss, in reality there will be a little in-phase current).  When there is a secondary load you get an in-phase component of current flowing in the primary, and electrically that (multiplied by the primary voltage) represents the power being transferred to the secondary.  IMO your tests agreed with all this transformer action.

The increase in secondary voltage as you moved the core into the primary coil is fully explicable and what would be expected.  The primary inductance value gradually increased, and since flux for a given current is proportional to L, this resulted in increased flux hence increased secondary voltage.   

As regards the air cored tests showing maximum voltage with the secondary coil at the centre, this fully demonstrates the typical flux pattern in a solenoid.

Smudge
« Last Edit: 2015-12-06, 16:51:08 by Smudge »
   
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I should have commented on your test with the steel flanges on the secondary coil.  It is the flux passing though the coil that does the work so your flanges did nothing to alter that "hole" through your coil.  I think you expected some screening action against flux that impinges on the wires and that is the wrong flux.  There is a form of flux cutting when a conductor moves within a magnetic field, or when a magnet is moving relative to a fixed conductor, and there the flux lines must impinge on the wire.  But not in the case of transformer induction.  The E field that drives the electrons in the wire can be outside the B or H field, in a region where B or H is zero.  In transformers where the flux is contained within the core that is generally the case, there is no flux impinging on the wires.

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The so called 0 volt line is just a reference point-a point without potential.
It is from this point we can view in which direction the current is flowing. Your scope shows current flow direction in the sine,and the amount of force(pressure) that current is flowing at. It's not  above or below 0 volt's,it;s forward or backwards of current flow,as you cannot have less than 0 volt's.

You just have to take a stand alone generator to see this. Now you have no ground,but your scope will still show a sine across the potential of that generator. If you hold the output wires from that generator(not advisable)in your hands so as you have one wire in one hand,and the other wire in the other hand-one half of the sine will show you current flowing into your right hand and out of your left hand,and the other half of the sine will show you it is flowing into your left hand and out of your right hand.
I would expect the MOT(secondary) to output more power through the load if a steel plate were placed either side of it,as the steel plate would draw in more of the radiant magnetic field around it that would normally not pass through it. So the magnetic fields now being attracted to the steel plates either side of the MOT must pass through the MOT,as the field will want to link-continue it's journey. So no, I don't think the steel plates will deflect the field,i think it will concentrate it.
Brad

@TinMan

Sorry for the delay in responding to your post above. Been really busy.

Yes, I was sort of expecting such a reply and you may be right, but first you or others need to explain why the AC neutral is always connected to Earth ground. So............ if it is like they say, then the positive is on one wire per half cycle, then on the other wire in the other half cycle but going the other way (seen as the negative sine), while the inverse polarity is always on the other side of the coil per cycle, so as it is said "in alternating directions". So how is that possible with a line going to ground? How can current flow from or in the other direction when the ground always remained ground? Or maybe, just maybe, there is no "current flow", just atomic spin conveyance which would explain it perfectly with zero need for current flow, fields or electrons. Just something to think about.

I think that some may want to go all the way back to the original AC patent by the great Tesla. Reread it to reunderstand it and also maybe also realize that Tesla, as far as I can ascertain in his patents never used the words "field" or "electron", yet, he was able to advance the industrial condition of the world because he kept his perspective pure to the effect, while all of our past and present geniuses use the words field and electron in every sentence without ever knowing what the hell they are supposed to be in reality while Tesla always kept himself true to the effect never using words that do not mean exactly what he wanted to convey. That's the curse of a high level perfectionist, never bowing to ambiguity. hahaha

Question: Our present day CPUs run our computers. So how many fields are in a CPU? How many electrons should be traveling in the CPU? What is all this crisscrossing of fields and electrons doing to the CPU to enable it to work the way it does? Try to explain this in a logical manner and you will soon realize that it is impossible for either to be active in a CPU, only atom to atom mutual effects are possible to switch O's and 1's. So science can slip this CPU discovery into our lives without anyone ever realizing it contradicts the very nature of the EE perspective. Seems like academia has to slip this in but had to keep the discourse symbiotically in line with Standard EE. OK, more on this later if you want.

Thanks for doing your last Tesla coil and Mot pickup coil video. I know you found it to be a drag but good or bad, we always learn. If I was in your lab I would have maybe suggested to try and ground the plates as well or even stick a small magnet to each and see again. Small things that change the environment of the test quickly and teach more about the effect, if any, either way gives answers. And just think, without that video, we would not have @Smudges' great post right after which I will get into hopefully soon and sorry for the delay. There is simply so much to cover and I have to push myself now to really get into and start my Spin Conveyance thread since all these discussions would tie in much better for guys to catch a new drift. My only hesitation is once I start it, there is no turning back and I am afraid I will have to devote all of my time, including my bench time, to this one effort and that is one thing I would really not to want to lose. My personal hope is that once I start it, that a few others will hop on and help out, but I will not hold my breath and really consider it be a solitary project.

wattsup


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Hi guys,

I am not sure I understand all that is being discussed but a question was asked by wattsup that I can answer.  I do know why the neutral wire is connected to ground.  I worked as an industrial maintenance electrician for over 30 years.   When we had a robotic storage and retrieval system installed where I worked they started having a lot of problems with the computer system that controlled the inventory and told the robotics where to go to get a particular part.  My boss asked me to see if I could find out what was going on.  I took our disturbance analyzer to the ware house and connected it to the power system for the computer system.  When I checked it the next day I found all kinds of spikes and surges in the 110 volt power for the computers.  I also saw that the so called neutral wire was sometimes floating as high as 150 volts above ground potential.  I then traced the problem to the fact the contractors had NOT tied the neutral of the secondary side of the transformer to ground.   If a user had touched the metal case of any of the computers and at the same time been touching a solid ground they would have gotten a nasty shock.  As it was the floating and noisy 110 volts for the computers was causing all the problems.  Grounding the secondary side of the transformer neutral took away the spikes and floating voltage on the neutral and then the computers worked fine.

Carroll


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