Fly-back voltage vs back-emf

[peacepenguin]

I'm hoping to get some clarification on these two terms.

fly back

and

back-emf

the way the terms are used are very confusing. Paul Babcock says Flyback voltage is what hes capturing and recovering. bedini says hes using a voltage spike from the coil collapse.

bedini also says that what he's using is NOT back emf.

so why is everyone talking about capturing back emf? is Flyback the same as back emf? Wikipedia doesn't clarify very well either.

is Flyback a component of back emf, or is back emf a component of Flyback?

or are they completely different phenomenon?

any guidance or advice would be appreciated.

thanks

-Ben

-------------------------

UPDATE (sept. 17, 2012):

I think the answers to the original questions posted above have been answered quite well in the first page of the thread. And also in the thread mentioned here that Aaron started on "back emf vs inductive spike". I feel very good about my understanding of how a flyback voltage is actually a "forward" emf in the direction of the applied voltage, after the applied voltage has been cut off from a charged inductor.

Back emf or Forward emf, either way its a voltage generation (emf = voltage). more of a matter of perspective and timing than anything "fundamental". the only thing fundamental is the voltage generation. Generators and motors both create forward and backward emf during normal operation, so Peter's electric motor secrets seems to be the best place to start for fundamentals. then electric motor secrets part 2 if you want your mind blown, in a good way.

The flyback is a phenomenon of an inductor discharging quickly. Also known as "inductive spike" or "inductive collapse". Lots of great links to be had from the members, thanks for all the help and pointers to previous threads.

Interesting that inductive collapse is used by many "free-energy" devices: Bedini SSG, Kromrey or G-field, and Dollards analog computer "in longitudinal mode". Those are my favorites and sure enough they all have a flyback or inductive collapse effect. I think EV Gray's machine involved it too. Dollards is my favorite since it RESONATES these inductive collapses, adding even more voltage amplification.

(Some ramblings now): I'm fully convinced that some "other" things like HHO production from water at super efficiency is possible when you begin approaching the intense high voltages generated by a flyback transformer. Similar to Stan Meyers water cracking, which has some very obvious inductors placed near the water. especially exciting since you can use such a tiny amount of input current at tiny voltage to generate these mega-voltages. seems to be related to PLASMA creation. that "4th state of matter" that appears to be "electrified matter" and nothing like normal matter at all.

Now on an unrelated but fun issue, there is more bad information, mis-information, dis-information, distracting information, whatever you want to call it on this single thread than I have seen in a lot of personal trolling on forums over the years. I am encouraged by that fact because if any thread needed corrupting, it seems like it would be one that is "close to something needing protecting".

Anyway thanks for all the responses, including the intentionally misleading ones!

-Ben

[citfta]

Hi peacepenguin,

I understand your confusion. The confusion comes from all the hobbyists that hear a term and start using it without really understanding what is means. If you talk to someone who has actually been trained in electronics they will tell you flyback and impulse spike are the same thing. Back EMF is not the same as impulse spike or flyback spike. Back EMF is only generated when current is induced into a wire from it moving in a magnetic field or when the magnetic field is moving in relation to the wire. If we apply power to a motor we put current through the armature either directly through brushes or indirectly through induction. This causes the armature to turn. The turning armature in turn now starts generating a voltage that opposes the original voltage. This is back EMF. As the motor comes up to speed the bemf will reach the point where it reduces the forward current to a level that is just enough to overcome friction losses and power the load. As we increase the load the motor slows down and the bemf is reduced. This allows the motor to draw more current and thus it is able to maintain speed under load. I know there is a lot of talk of this forum about how bad bemf is but in a normal motor bemf acts like a governor to help the motor to maintain a nearly constant speed under varying load conditions.

Impulse spike is caused by suddenly removing power from an inductor. Usually it is a coil such as in the Bedini SSG. It can also be the field windings of a motor or the windings of the armature of a motor. Even a simple solenoid will generate a spike when it is turned off. In a television this property is used to drive the electron beam from one side of the screen to the other. A voltage is applied to the horizontal deflection windings which drives the electron beam from the left to the right at a certain speed. When the beam gets to the right the power is suddenly cut off from the deflection yoke and the spike is used to make the beam FLY BACK to the other side of the screen to start all over again. This is where the term flyback came from. The spike is also used in a TV to give a kick to the high voltage transformer which most people call the flyback transformer. This transformer is used to develop the high voltage needed for the CRT to work.

Respectfully,
Carroll

[gyula]

hi Ben,

The best thing to see clearly is to know the physical phenomena behind them.
Many forum members, even those with born English language, do not use these terms correctly, they are negligent... and then there are those who use English as a second language. However these cannot be an excuse.

There was an attempt to clarify the terms here:
http://www.energeticforum.com/renewa...eld-spike.html

rgds, Gyula

PS I just noticed Caroll answer to you and I agree with the explanation.

[Dave45]

What most dont take into consideration is that there is a forward emf as well as a bemf both can be used to make free energy, when the magnetic field of an inductor collapses it moves in two directions femf and bemf , the femf which is not as noticeable moves on into the load and bemf runs back to source, the bemf is the one that is most noted because of its destructive spikes but femf is there as well.

dave

[Ufopolitics]

Hello Dear...

I'm hoping to get some clarification on these two terms.

fly back

and

back-emf

the way the terms are used are very confusing. Paul Babcock says Flyback voltage is what hes capturing and recovering. bedini says hes using a voltage spike from the coil collapse.

bedini also says that what he's using is NOT back emf.

so why is everyone talking about capturing back emf? is Flyback the same as back emf? Wikipedia doesn't clarify very well either.

is Flyback a component of back emf, or is back emf a component of Flyback?

or are they completely different phenomenon?

any guidance or advice would be appreciated.

thanks

-Ben

Hello Dear Peacepenguin,

Just for the record, I will write my opinion now, before it gets deeper into further pages...not precisely about the B EMF or the Spikes...but my opinion about the Thread in general...

Ok, so if You thought You are confused now...because of all the different opinions and controversial points of view as contradictions on this subject out there...that obviously tends to confusion...

Wait til this Thread develops further on...

I wish you the bests of luck and a very open mind...


Regards


Ufopolitics

[Dave45]

I agree this can get very confusing look to the basics, dont overcomplicated something that is very simple.
HowStuffWorks "Inductor Basics"

The reason for this strange behavior is the inductor. When current first starts flowing in the coil, the coil wants to build up a magnetic field. While the field is building, the coil inhibits the flow of current. Once the field is built, current can flow normally through the wire. When the switch gets opened, the magnetic field around the coil keeps current flowing in the coil until the field collapses. This current keeps the bulb lit for a period of time even though the switch is open. In other words, an inductor can store energy in its magnetic field, and an inductor tends to resist any change in the amount of current flowing through it.

The current that keeps the bulb lit after the switch is opened is femf.

[Farmhand]

Hi PeacePenguin, Carroll explained it very well, Back emf is described in this
guide on transformers. I included a quote because I think this is important
for people to understand. Back emf is not our enemy. Good idea to start
a new thread about it.

Transformers Part 1 - Beginners' Guide to Electronics

3. How a Transformer Works
At no load, an ideal transformer draws virtually no current from the mains, since it is simply a large inductance. The whole principle of operation is based on induced magnetic flux, which not only creates a voltage (and current) in the secondary, but the primary as well! It is this characteristic that allows any inductor to function as expected, and the voltage generated in the primary is called a "back EMF" (electromotive force). The magnitude of this voltage is such that it almost equals (and is effectively in the same phase as) the applied EMF.

Although a simple calculation can be made to determine the internally generated voltage, doing so is pointless since it can't be changed. As described in Part 1 of this series, for a sinusoidal waveform, the current through an inductor lags the voltage by 90 degrees. Since the induced current is lagging by 90 degrees, the internally generated voltage is shifted back again by 90° so is in phase with the input voltage. For the sake of simplicity, imagine an inductor or transformer (no load) with an applied voltage of 230V. For the effective back EMF to resist the full applied AC voltage (as it must), the actual magnitude of the induced voltage (back EMF) is just under 230V. The output voltage of a transformer is always in phase with the applied voltage (within a few thousandths of a degree).

For example ... a transformer primary operating at 230V input draws 150mA from the mains at idle and has a DC resistance of 2 ohms. The back EMF must be sufficient to limit the current through the 2 ohm resistance to 150mA, so will be close enough to 229.7V (0.3V at 2 ohms is 150mA). In real transformers there are additional complications (iron loss in particular), but the principle isn't changed much.

If this is all to confusing, don't worry about it. Unless you intend to devote your career to transformer design, the information is actually of little use to you, since you are restrained by the "real world" characteristics of the components you buy - the internals are of little consequence. Even if you do devote your life to the design of transformers, this info is still merely a curiosity for the most part, since there is little you can do about it.

When you apply a load to the output (secondary) winding, a current is drawn by the load, and this is reflected through the transformer to the primary. As a result, the primary must now draw more current from the mains. Somewhat intriguingly perhaps, the more current that is drawn from the secondary, the original 90 degree phase shift becomes less and less as the transformer approaches full power. The power factor of an unloaded transformer is very low, meaning that although there are volts and amps, there is relatively little power. The power factor improves as loading increases, and at full load will be close to unity (the ideal).

Cheers

[Dave45]

This is the best part

If this is all to confusing, don't worry about it. Unless you intend to devote your career to transformer design, the information is actually of little use to you, since you are restrained by the "real world" characteristics of the components you buy - the internals are of little consequence. Even if you do devote your life to the design of transformers, this info is still merely a curiosity for the most part, since there is little you can do about it.

[peacepenguin]

thanks for the insights!

so the high voltage Flyback of an open circuited inductor can reach insanely high voltages. very cool.

I think I understand what Dollard and Peter were doing in the old borderlands video with the "analog computer" in "longitudinal" mode.

an inductor is charged, then discharged into a capacitor using the Flyback voltage gain. then capacitor discharges to next set of inductors, which then collapse, again at a much higher voltage. cool, but then as if that's not enough voltage you can get more on each impulse by sending a sine wave.

by applying a high frequency input sine wave, if tuned correctly, it will resonate with the charge - discharge cycle of the inductors. this causes each step to gain resonance type of multiplication of voltage at each step, in addition to the Flyback transformer effect.

strange stuff, maybe there's a gain in power to be had from that insanely high level of voltage amplification. ozone or hydrogen production at least.

-Ben

[jpolakow]

What most dont take into consideration is that there is a forward emf as well as a bemf both can be used to make free energy, when the magnetic field of an inductor collapses it moves in two directions femf and bemf , the femf which is not as noticeable moves on into the load and bemf runs back to source, the bemf is the one that is most noted because of its destructive spikes but femf is there as well.

dave

I would definitely have to disagree here. BEMF and FEMF dont happen in the same time frame, and there is no "free energy" here.

Most know when a current flows through a wire it creates a magnetic field. Well this magnetic field OPPOSES the current that created it. This magnetic field around a wire opposing current flow IS the BEMF. Normally this has little to no effect in a conductor, but when a wire is wound into a coil, the magnetic fields created by the wire add together to oppose current flow. This is the essence of BEMF, it is the magnetic field of the current flowing.

BEMF by its nature, opposes current flow, it is seen as a resistance to it. In actuality it exchanges or "stores" current into the magnetic field of the coil. It cost current to make that magnetic field. Now you cannot "capture" BEMF just as you cannot capture the electricity used up in a resistor exchanged into heat. Whereas a resistance exchanges electricity into heat, BEMF stores the energy in the magnetic field. When this stored magnetic field energy is used, or brought back into the circuit, the name changes from BEMF into FEMF.

Where BEMF opposed current flow, FEMF aids it. FEMF is what most refer to as "capturing the BEMF", or the inductive spike. When I first heard of the term "capturing the BEMF", I pictured in my mind current shooting back through the coil, opposite the way it went in. This is NOT what is happening. Current stays in the same direction. With current flowing through the coil, there is the magnetic field of stored 'energy' around the coil. If current through the inductor is reduced, due to a switch opening or the EMF applied to the coil being lowered, the magnetic field returns some of its energy to the circuit to try to keep current constant. This is how a large voltage spike is created. How big the voltage spike will be is directly proportional to how fast the current through the coil is changed. If a switch is instantly opened, and the current is suddenly reduced, the stored magnetic field can generate a near infinite EMF to discharge its field potential.

However, there is no free energy here. The coil is just a storage medium for magnetic energy. What you put in is what you get out, under ALMOST all circumstances. In practice, the voltage spike of FEMF can damage electronic components so it is discharged by a diode, not used, energy discarded. Greater efficiency can be gained by using the energy of the FEMF to do something useful, because it normally is thrown away, but there is no free energy here.

What is constant is the energy stored in the magnetic field, and the energy of the discharge. If the magnetic field generates a huge FEMF(due to a sharp change in current), the time of that current discharge(the time constant) will be shorter than a discharge with a smaller FEMF(smaller change in current) generated. Different voltages, different time frames, same amount of energy.
Simply put, BEMF is storing magnetic energy and FEMF is returning it.

[Ufopolitics]

My Opinion

I would definitely have to disagree here. BEMF and FEMF dont happen in the same time frame, and there is no "free energy" here.

Most know when a current flows through a wire it creates a magnetic field. Well this magnetic field OPPOSES the current that created it. This magnetic field around a wire opposing current flow IS the BEMF. Normally this has little to no effect in a conductor, but when a wire is wound into a coil, the magnetic fields created by the wire add together to oppose current flow. This is the essence of BEMF, it is the magnetic field of the current flowing.

BEMF by its nature, opposes current flow, it is seen as a resistance to it. In actuality it exchanges or "stores" current into the magnetic field of the coil. It cost current to make that magnetic field. Now you cannot "capture" BEMF just as you cannot capture the electricity used up in a resistor exchanged into heat. Whereas a resistance exchanges electricity into heat, BEMF stores the energy in the magnetic field. When this stored magnetic field energy is used, or brought back into the circuit, the name changes from BEMF into FEMF.

Where BEMF opposed current flow, FEMF aids it. FEMF is what most refer to as "capturing the BEMF", or the inductive spike. When I first heard of the term "capturing the BEMF", I pictured in my mind current shooting back through the coil, opposite the way it went in. This is NOT what is happening. Current stays in the same direction. With current flowing through the coil, there is the magnetic field of stored 'energy' around the coil. If current through the inductor is reduced, due to a switch opening or the EMF applied to the coil being lowered, the magnetic field returns some of its energy to the circuit to try to keep current constant. This is how a large voltage spike is created. How big the voltage spike will be is directly proportional to how fast the current through the coil is changed. If a switch is instantly opened, and the current is suddenly reduced, the stored magnetic field can generate a near infinite EMF to discharge its field potential.

However, there is no free energy here. The coil is just a storage medium for magnetic energy. What you put in is what you get out, under ALMOST all circumstances. In practice, the voltage spike of FEMF can damage electronic components so it is discharged by a diode, not used, energy discarded. Greater efficiency can be gained by using the energy of the FEMF to do something useful, because it normally is thrown away, but there is no free energy here.

What is constant is the energy stored in the magnetic field, and the energy of the discharge. If the magnetic field generates a huge FEMF(due to a sharp change in current), the time of that current discharge(the time constant) will be shorter than a discharge with a smaller FEMF(smaller change in current) generated. Different voltages, different time frames, same amount of energy.
Simply put, BEMF is storing magnetic energy and FEMF is returning it.

Hello Jpolakow,

I am sorry, but I have to disagree with you and be on total agreement with Dave 45...
And We must NOT only go by the laws they taught Us as per other opinions...BUT MAINLY by Our own Lab and Development Work on this fields , in order NOT to state conclusions merely based on others explanations and concepts.

BEMF and FEMF dont happen in the same time frame, and there is no "free energy" here.

There are always TWO Forces of Current flow , traveling in any given conductor that We have excited by sending our artificial generated Flow. This currents Oppose to each others BUT are absolutely NOT in conflict related to each others...They BOTH can travel in opposite directions within a single strand of wire. There are MANY simple testing that can prove that FACT.

And I really do not mind what "Name" we give them ...but I know they BOTH EXIST.

Most know when a current flows through a wire it creates a magnetic field. Well this magnetic field OPPOSES the current that created it. This magnetic field around a wire opposing current flow IS the BEMF. Normally this has little to no effect in a conductor, but when a wire is wound into a coil, the magnetic fields created by the wire add together to oppose current flow. This is the essence of BEMF, it is the magnetic field of the current flowing.

A Magnetic Field manifests, lives and propagates into Space, Open Space... while a current, an electron flow of OUR generated side, can ONLY travel,move, within a given path called conductor(s). Therefore, A Magnetic Field Can NOT oppose DIRECTLY to any other flow that exist in other Space or Limited Area...except trough ANOTHER Flow directly related to that Magnetic Field that executes within same dimension of Our Flow.

When We create a Magnetic Field through our Coils it goes "free out to space" beyond the means that created it (our flow), it projects an Irregular Three Dimensional Spectrum that develops/blows out of that Coil, out of that wire...then it triggers a series of OTHER parameters/events beyond our flow, where starts an exchange of atomic and molecular alignments and positioning within that 3D Space. This whole process-completely out of the reach of our electron flow scope-keeps developing as long as We keep supplying the flow that generated the MF.

The "Capacity" of Storage of Our Flow within a Coil is very small related to time frame...A Coil NEVER, could store a charge like a Capacitor does...it is very close to zero point.

We can not just see/judge our analysis based on JUST our "Physical" current (electron) flow within a conductor when we are generating Magnetic Fields, precisely because, a MF goes into Spaces and Dimensions where our flow just CAN NOT pass/exist/travel/develop...We could "Influence" INDIRECTLY that Magnetic Field through our signal flow...However, We MUST have in mind that Field DOES Exchange/Influence and "work" with a Dimension beyond our electron physical flow.

When We Collapse Our Magnetic Field, We MUST ALSO look at what has happened to ALL those "Aligned Spaced Dimensional Particles" at Molecular-Atomic levels, around Our existing Generated MF...and what consequences it brings into our Circuit when the Collapse of Our Field occurs...we CAN NOT disregard this FACT because it DOES Influence Our Flow and in great fashion.

The "Disregarding" of this Real and Existing Field Process of ANY Magnetic Field with the Aether, the Three Dimensional Space, Radiant Energy Field or whatever name will like to be baptized with...have caused ALL the Confusion and Arguments We all face up to now...We must "Thanks" Mr. Hendrik Lorentz for doing this MUTILATION under the "Influential Funding Interests" of J.P Morgan and Thomas A. Edison...as also did Mr. A. Einstein to be able to sustain a "Theory" that Up to NOW...No One have been able to prove it really "functions as He wrote"...

Regards


Ufopolitics

[mbrownn]

Interesting thread, Both BEMF and flyback voltage (I use the term inductive kickback) are terms used to describe observed phenomenon ie observations. I think we have already explained in this thread what those observations are in terms of the effects seen, but the truth is we still do not have a definitive answer as to what "electricity" is, how it is formed and how it interacts with magnetism (if indeed it does) and everything else.

The quote below hints at what may be behind it all, but that is subject matter for another thread.

Hello Jpolakow,

However, We MUST have in mind that Field DOES Exchange/Influence and "work" with a Dimension beyond our electron physical flow.
"Aligned Spaced Dimensional Particles" at Molecular-Atomic levels, around Our existing Generated MF...and what consequences it brings into our Circuit when the Collapse of Our Field occurs...we CAN NOT disregard this FACT because it DOES Influence Our Flow and in great fashion.


Regards


Ufopolitics

Dave45 covered it for us as did farmhand.

[tecnovative]

What we have here is a nomenclature problem. The term "Back-EMF" is used as slang to describe multiple electromagnetic phenomena and creates much confusion. Basically from a Lenzian perspective Counter-EMF refers to the phenomenon of a self-induced current that opposes the input current by flowing in the opposite direction briefly as a magnetic field builds around an inductor. FSU has a reasonable description and simple DC circuit animation on their MagLab website.

It appears the most common usage of terms like "Back-EMF", "Back-Spike", or "Fly-Back" by experimenters is in reference to the high voltage spike that occurs when the electromagnetic field around an inductor collapses. Since this spike actually flows in the same direction as the input current it might be more correctly described as a Forward-Spike or Collapsing-Field-Spike or Counter-Counter-EMF.

[Dave45]

This model shows both bemf and femf
The magnetic field is electricity, just separated into voltage and amperage.

dave

[Ufopolitics]

Seeing in different "Colors"...

This model shows both bemf and femf
The magnetic field is electricity, just separated into voltage and amperage.

dave

Hello Dave, nice Diagram!

A Diagram has the ability to speak for a thousand words!!

Now, one thing I will like to add to your Diagram...

If, instead of an incandescent bulb (like is shown) We place a Neon...and we use an Oscillator... instead of a switch...and start VERY SLOW pulses, very low hertz...and connect a nice Digital (Digital because it is a faster response tronics) Scope to read the Square Waves...

We will notice the Neon will turn Orange light when pulse is at On Time...while it will turn Purple Plasma Sphere Light, at time off, and still display some residues of orange....

Now, our human vision is limited when it comes to pulses of Radiant Light...as also some cheap cameras...so...I recommend to film it with an HD Cam...then play back at slow motion with a nice Editing Software...and enjoy the "Show"...

Then make your own Scientific Conclusions and let me know...

Regards


Ufopolitics

Edit: Oh, I forgot!!...If you are not seen the purple light well defined, then you could add a couple of diodes (rectifiers) and deriving the Neon from the opposite to Hot flow side...this will avoid our pulses to get to neon directly, but only through the diode reversed and minimal flow, according to its spec's.