Back EMF vs Collapsed Spikes.....

[EMdevices]

I watched the video and it's very weak and incorrect in some respects, although it brings out a good point and that is to use proper language so we know what is being discussed.

Here's a few things that jumped out.

1)  picture showing the coil after current is interupted is labled wrong.  It showes the South pole at the top (where the North pole use to be)  and it should be the North pole.    The poles depend on the direction of the current at that instant. not on any changes  (the voltage polarity is what changes, based on whether the field is increasing or decreasing)

2)  He says to askyourself a few questions.   His assumption is that no current flows when the coil is opened.   Well, I got news for you, there is current flow because there is capacitance (interwinding, switch capacitance, etc.)   When you flip a switch what you actualy do is switch in a capacitor, albeit, a very small capacitor if you have a good switch.   So what you get is actually a tank circuit that resonates realy fast if no breakdown occurs, but usualy air breakdown occurs (or coil breakdown) and the energy flows into heat, light, and rf.


Here's two points that should be kept in mind.


1a)  If an external magnetic field "B_ext" INCREASES in a coil, a voltage appears across the terminals of the coil  such that if current is allowed to flow (by shorting the leads etc..) it would generate a magnetic field "B_gen" in the coil that OPPOSES the original one.   In other words,  if B_ext points UP, B_gen points DOWN.  HOWEVER THE TOTAL FIELD STILL POINTS IN THE DIRECTION OF B_ext since its the largest field.

1b)  If an external magnetic field already present begins to decrease,  the coil responds with a polarity such that if current is allowed to flow it would OPPOSE THE CHANGE, but in this case, the generated magnetic field would point IN THE SAME DIRECTION.  HOWEVER THE TOTAL FIELD STILL POINTS IN THE DIRECTION OF B_ext since its the largest field.


Is that awesome or what?

A simpler way is to think that the coil responds to prevent changes in the field, period. (Lenz's Law)  So to prevent an increasing field you create a field of opposite polarity, and to prevent a field from decreasing you aid it with one of the same polarity.   
Now, did you know that in a transformer core that's transfering power, the magnetic flux is almost zero?   Can you think why that could be based on the above?


Now,  what if there is no EXTERNAL MAGNETIC FIELD, that's doing the changes?

Well, this is the neat part,  it doesn't matter who/what creates the magnetic field !!!!   It could be the coil itself !!!  In actuality the coil responds to the TOTAL MAGNETIC FIELD, that is, the sum of all magnetic fields in the universe that have some flux that passes through the coils area.

So if we say there are no external magnetic fields, how can a coil itself create a magnetic field,  and at the same time OPPOSE it?  How can it grow?

Well, it works, you see,  when you apply a voltage to the terminals of the coil, the current doesn't increase instantly to  I x R = V, where R is the resistance of the coil.   The reason is because of the back EMF that develops (or this reaction of a coil to changing magnetic fields, also called CEMF or Counter EMF)   The reason it's called "BACK"  and not "FORWARD" is because it OPPOSES the voltage applied, or comes "BACK" at it, but counter is more intuitive, however BackEMF seems to be used more widely.

So anyway, apply 10 Volts to a coil, and instantly 10 volts of Back EMF showup to oppose, and zero volts IR show up as well (no current flow yet.)

But the 10 volts BEMF, can't be kept up.  They are generated as a response to a CHANGEING magnetic field,  but how can you have an increasing magnetic field if you don't let the current flow?  And current can flow only if there is a difference in voltage potential , so 10 volts -10 volts is zero at the instant of application.    

Well there is a compromise, a middle ground where everybody is happy. 

You see current begins to flow at a SET RATE  of  di/dt = V/L, so the rate of change of the current (di/dt) is equal to the voltage divided by a constant called the inductance of the coil.  So basicaly, the current needs to increase so there can be an increasing magnetic field that will induce the backEMF or else the current will increase instantly and produce a large magnetic change which will create a larger voltage then 10 volts which will try to drive current the other way, so a middle ground exists, a fine ballance of electromotive forces and all this can be dervied with mathematics, but I won't bore you with it. 

So in an ideal coil (superconductor perhaps) the current increases LINEARLY from zero, and it's slope is V/L.  The magnetic field this current produces is obviously related to the current and it too will increase linearly (that's why it generates the voltage at the terminals after all, which prevents instant current jumps, or discontinuities) 

However, in a coil that is resistive, as the current increases more and more of the opposing EMF changes from the Back EMF to the IR voltage drop.  This is not an EMF which means Electro-Motive-Force, because its a passive "force" more like a resistance.  LOL.     Anyway, it begins to produce a resistive voltage drop across the coil resistance, and pretty soon it reaches a high enough level where the 10 volts drop is now supported entirely by the I^2R losses, as they are called.   We all knew current can't increase forever.     

So we have an exponential transition from pure Back EMF to a pure I*R voltage drop as a voltage is applied to a coil and current begins to flow.

Ok, that's enough for now, I don't want to upload to much of my knowledge or I'll start to fully believe it myself.    LOL   

EM

[libra_spirit]

To further complicate this one must start to look at power factors and phasing schemes! Transmittion lines and antennas, and power grids.

To understand copper and how the mass of the copper atoms is floating inside the electron shell, we get the sense of sloshing back EM or CEMF. [NMR theory] There is a delay of 90 degrees between the voltage and the current and this translates into a very real and true angle in space.

The isotope chains in copper are magnetic and attach end to end precessing and connected on there ends between adjacent atoms. This is the bassis of David Hamels cones using Aluminum. The Nuclear magnetic field is weak in atoms but in copper aluminum and bismuth it is strong enough to couple with the electron shell for manipulation of the mass of the atoms, as the electrons shells are normally neutral or non magnetic.

A non energized copper wire therefore has an isotope chain in place already that is aligned the longest length of its mass. The nuclear magnetic field is running the wires length and precessing at the NMR frequency, a long magnetic chain with inertial momentum and spinning backwards of the electrons. A small counter EMF is already present setting at 90 degrees to the wire.

This is why scalar coils are felt to be charged without any actual currents in them, and why so many devices using coils and crystals generate torsion fields using no current whatsoever.

When a voltage hits the wire, before current even starts to flow, this neuclear alignment is resistant to the flow of electrons in the wire and delays them from being dislodged until a mass rotation occurs at the nucleus. The voltage vector at this point sits at 90 degrees to the coil, and we see it instantly arise in a wire passing through the center of the coil at 90 degrees in space. For this special case of coupling the voltage vector has no delay from the normal 90 degree lag in copper coils because it is already aligned to recieve it.

The instanious E field spike passes through to the 90 degree coil or conductor and can be viewed using a scope. This is TPU style effect, right out of NMR theory.

Now as the first coil begins to conduct electrons the mass of the copper atom at the nucleus begins to rotate into alignment with the new magnetic field on the electron shell and we discover the actual reason for the 90 degree phase shift in copper. The isotope chains are now broken between the atoms down the length of the wire and the mass tries to keep up with the E field wave as it changes. The nuclear magnetic field turing to try and catch the electron shell creates a reverse EM in the electron shell because its spin is the opposite direction. We see here now the reversed EM is out of phase with the initial EM hitting the coil.

Experiment using a spherical system of only copper exposes this for observations. The back EMF can never catch the forwards EMF in space because it cannot turn as fast. Nuclear rates are in the Mhz and Electron shell rates are in the microwave rates for ability to turn quickly. The mass of the nucleus is over 1000 times heavier then the electron shell so the nuclear field turns sluggish.

This splitting of the two fields in space during a changing E field, is the reason for both the effects describbed for back EMF and Counter EMF. The "back" indicates it is being generated on the "nucleus" of the atom which spins backwards to the forwards EM which is entirely electron shell mechnism. They may be describbed differently in electronics theory but in NMR theory a different model emerges.

This becomes more apparent when one starts to observe the NMR traces on scopes in copper wire using coils at 90 degrees. And here is where you begin to see that OU is possible, as there is obviously more energy resulting from a changing E field in coils then it takes to set up this turn. If both fields could be captured while they are split the energy gain is now only a function of how far you manage to split them in space. This is why the fast rise time of the square waves is criticle to harness the split time.

If the reverse field was being created at the electron shell, as the current and incomplete electronics theory indicates, then there would be no phase shift of voltage and current in copper wire at all, the reverse spin would be instant and current would never rise at all. The copper atoms would become diamagnetic and simply be repelled by any magnetic field present wether changing or not. There would be no E field spike on the leading edge at 90 degrees to the wires length.

I believe this is a case where two seperate fields of technology have yet to merge. Most electronics people are resistant to start opening the atom to this depth but here is where the true function lies. We can no longer turn a blind eye as OU engineers, to the depths of the atom and what is already known. The writesr of Lenz Law had no concept for this, it was discovered in the 50s.

The inertial spin momentum of the nuclear mass is normally countering the electrons spin of mass, when the two are split in angular alignment, both surge upwards as long as they remain out of phase. The copper not only reacts to current induced on its electron shell surface but it is also a generator of the forces moving through it which normally nearly cancel.

The back EMF is ever present in copper all the time, it is buried just below the surface as countering inertial momentum force.

Dave L

[quantum1024]

@ libra_spirit

Hi, libra. Several days ago i read your post above and some things started to make sense while others are over my head. what I do understand is a bit fuzzy still, even after reading your post for several days repeatedly.

I too have been asking the same questions, where does this impedance come from and what is the cause of the 90 degree phase shift, why is geometry so fundamental and has not been studied in detail. What would a triangle coil do as apposed to a square coil.

confirms what you are saying basically, i think... here is the phase shift
http://www.springerlink.com/content/pu43p4h827m34386/

And here..
http://books.google.com/books?id=DuOiW_N1yTAC&pg=PA410&lpg=PA410&dq=nuclear+spin+of+copper&source=web&ots=8Vvai1VM6s&sig=g2RcjtGGAHpHtsK9qARUXv7QJj4

So what I think your trying to say is that, voltage potential effects electrons, more so then current, and current effects nucleus spin, that electrons don't, and that the different spins are what creates the 90 degree phase shift. is this about right?  and that current which is held back by entropy (nuclear field turns sluggish),
creates the phase shift.

So now if I look at a triangle coil, I think i might be able to see what is going on... You have a long wire which then has a sharp turn, and then a long wire again. The current hitting the turn point will be the interesting area. must experiment now...

[MarkSnoswell]

This is the first time I have ever been compelled to correct and error of this sort in public. No offence is intended to anyone.

Please note that electrodynamic momentum should not be confused with nuclear interactions as stated below. This is incorrect. If anyone reading this wants to gain a deep understanding of what is really going on then Carver Mead's book on Collective Electrodynamics is perhaps one of the best places to start. The entire first chapter of the excellent book is available on line here http://www.pnas.org/cgi/reprint/94/12/6013?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=carver+mead&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

For those who don't choose to follow up on Carver Meads excellent book then I suggest the following simplifications: Current is a kinetic phenomenon with momentum. Voltage is a potential phenomenon. In a closed system energy will oscillate harmonically back and forth between kinetic and potential forms. The 90 deg relationship between kinetic and potential energy is a fundamental property of our universe that we are all intuitively familiar with. Hang a weight on a spring -- pull it down to put some energy in and then let go of it -- it oscillates. There is a 90 deg relationship between the potential and kinetic energy in the system. Voltage is like the potential energy stored in the stretched (or compressed) spring... current has inertia like the weight moving. This is what's happening in a coil that you apply a voltage to -- Initially the voltage is maximum and the current is zero... as the current begins to flow the voltage drops. Once the current is flowing it has inertia and it doesn't want to stop -- it creates a flyback.

[ If you want to atempt to gain a grasp of things at the following two levels of understanding then I suggest picking up a copy of Roger Penrose's excellent book, The Road to Reality.]

At a deeper level for those with a little mathematical inclination picture the energy as a coherent thing -- it can be described by a complex number. The amount of energy is constant - this can be represented by a radius in the complex plane. The energy will orbit the origin in a circle - always remaining constant in magnitude but oscillating in it's makeup of imaginary (kinetic) and real (potential) parts.

At a much deeper level harmonic oscillation is an inevitable, and simple, consequence of any consistent system of two or more dimentions. Potential energy is just a measure of entropy and kinetic energy a flow of entropy. The energy is a single thing that exists in a 2 dimentional metric. Although a single thing the energy dimentions are related by a 90 deg phase relationship and are best represented as a complex number.

Mark.

To further complicate this one must start to look at power factors and phasing schemes! Transmittion lines and antennas, and power grids.

To understand copper and how the mass of the copper atoms is floating inside the electron shell, we get the sense of sloshing back EM or CEMF. [NMR theory] There is a delay of 90 degrees between the voltage and the current and this translates into a very real and true angle in space.

The isotope chains in copper are magnetic and attach end to end precessing and connected on there ends between adjacent atoms. This is the bassis of David Hamels cones using Aluminum. The Nuclear magnetic field is weak in atoms but in copper aluminum and bismuth it is strong enough to couple with the electron shell for manipulation of the mass of the atoms, as the electrons shells are normally neutral or non magnetic.

A non energized copper wire therefore has an isotope chain in place already that is aligned the longest length of its mass. The nuclear magnetic field is running the wires length and precessing at the NMR frequency, a long magnetic chain with inertial momentum and spinning backwards of the electrons. A small counter EMF is already present setting at 90 degrees to the wire.

This is why scalar coils are felt to be charged without any actual currents in them, and why so many devices using coils and crystals generate torsion fields using no current whatsoever.

When a voltage hits the wire, before current even starts to flow, this neuclear alignment is resistant to the flow of electrons in the wire and delays them from being dislodged until a mass rotation occurs at the nucleus. The voltage vector at this point sits at 90 degrees to the coil, and we see it instantly arise in a wire passing through the center of the coil at 90 degrees in space. For this special case of coupling the voltage vector has no delay from the normal 90 degree lag in copper coils because it is already aligned to recieve it.

The instanious E field spike passes through to the 90 degree coil or conductor and can be viewed using a scope. This is TPU style effect, right out of NMR theory.

Now as the first coil begins to conduct electrons the mass of the copper atom at the nucleus begins to rotate into alignment with the new magnetic field on the electron shell and we discover the actual reason for the 90 degree phase shift in copper. The isotope chains are now broken between the atoms down the length of the wire and the mass tries to keep up with the E field wave as it changes. The nuclear magnetic field turing to try and catch the electron shell creates a reverse EM in the electron shell because its spin is the opposite direction. We see here now the reversed EM is out of phase with the initial EM hitting the coil.

Experiment using a spherical system of only copper exposes this for observations. The back EMF can never catch the forwards EMF in space because it cannot turn as fast. Nuclear rates are in the Mhz and Electron shell rates are in the microwave rates for ability to turn quickly. The mass of the nucleus is over 1000 times heavier then the electron shell so the nuclear field turns sluggish.

This splitting of the two fields in space during a changing E field, is the reason for both the effects describbed for back EMF and Counter EMF. The "back" indicates it is being generated on the "nucleus" of the atom which spins backwards to the forwards EM which is entirely electron shell mechnism. They may be describbed differently in electronics theory but in NMR theory a different model emerges.

This becomes more apparent when one starts to observe the NMR traces on scopes in copper wire using coils at 90 degrees. And here is where you begin to see that OU is possible, as there is obviously more energy resulting from a changing E field in coils then it takes to set up this turn. If both fields could be captured while they are split the energy gain is now only a function of how far you manage to split them in space. This is why the fast rise time of the square waves is criticle to harness the split time.

If the reverse field was being created at the electron shell, as the current and incomplete electronics theory indicates, then there would be no phase shift of voltage and current in copper wire at all, the reverse spin would be instant and current would never rise at all. The copper atoms would become diamagnetic and simply be repelled by any magnetic field present wether changing or not. There would be no E field spike on the leading edge at 90 degrees to the wires length.

I believe this is a case where two seperate fields of technology have yet to merge. Most electronics people are resistant to start opening the atom to this depth but here is where the true function lies. We can no longer turn a blind eye as OU engineers, to the depths of the atom and what is already known. The writesr of Lenz Law had no concept for this, it was discovered in the 50s.

The inertial spin momentum of the nuclear mass is normally countering the electrons spin of mass, when the two are split in angular alignment, both surge upwards as long as they remain out of phase. The copper not only reacts to current induced on its electron shell surface but it is also a generator of the forces moving through it which normally nearly cancel.

The back EMF is ever present in copper all the time, it is buried just below the surface as countering inertial momentum force.

Dave L

[quantum1024]

No offense taken here. Where all just trying to learn. Thank you for your kind statement. I have read Rogers book many many years ago.. forgot about that...

I am looking for a more basic and fundamental answer to what is happening in a coil.

1) Why is the voltage potential already far far ahead in a coil, what is the voltage potential anyway in a coil?

2) what is the voltage potential (or wave) doing to electrons? as it passes them?

3) what does current do to to the electrons? and how does it effect them during transfer.

4) if voltage is ahead in a coil by 90deg, does it build a magnetic field or is this strictly a combination of current and voltage or just current?


These are the fundamental questions which no one seems to be answering?

I thank you for any responses you can provide!

Fred