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Author Topic: Back-EMF Manifesto - A Key, hidden in plain Sight.  (Read 21835 times)

dieter

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #15 on: February 22, 2018, 12:26:54 PM »
Oh, and also important: the voltage height of the back-EMF highly depends on coil design, and therefor, the current will only flow backwards if it reaches a voltage higher than that of the supply. If it doesn't then, by means of logic, you are right. But it usually is higher. Often a multiple of the supply voltage.
Also important is a clean cutoff of the forward pulse.

tinman

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #16 on: February 22, 2018, 01:19:58 PM »
Oh, and also important: the voltage height of the back-EMF highly depends on coil design, and therefor, the current will only flow backwards if it reaches a voltage higher than that of the supply. If it doesn't then, by means of logic, you are right. But it usually is higher. Often a multiple of the supply voltage.
Also important is a clean cutoff of the forward pulse.

First of all,your mixing up BEMF with inductive kickback.

Second---> 

Quote
the voltage height of the back-EMF highly depends on coil design, and therefor, the current will only flow backwards if it reaches a voltage higher than that of the supply.

Where can i get one of these overunity coils?.

To clear things up

BEMF is normally used when talking about the generating effect of electric motors.

CEMF is normally what we use when talking about inductors and coils.
The CEMF is of the same polarity as the current source that created it,but is always a lower value.
If it were the same value as the source EMF,then no current would flow.

Inductive kickback refers to the self induced EMF across any inductor/coil,when the source of the current to the coil is broken/interrupted/disconnected.
This self induced EMF from the inductive kickback,is of the opposite polarity to that of the current source that created it.


Brad

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #17 on: February 22, 2018, 02:40:27 PM »

Magluvin

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #18 on: February 23, 2018, 12:24:53 AM »
author=Magluvin link=topic=17611.msg516966#msg516966 date=1519270261]


What is the reverse influence Mags?

Are you sure it's a magnetic field?

If we take a toroid core inductor for example-->is not the magnetic field contained within the core?
If so,then what field is collapsing inward around the wire ?

EMF is measured in volts--has nothing to do with current.

Brad

"What is the reverse influence Mags?"

Well after 'reverse influence' I have a comma and then I write CEMF, Counter 'Electro' Motive force' .  Not sure what is so hard to understand about that. ???


"Are you sure it's a magnetic field?"

Are you 'sure' it is something else? If so then please explain and or provide proofs otherwise. ;)


"If we take a toroid core inductor for example-->is not the magnetic field contained within the core?
If so,then what field is collapsing inward around the wire ?"

For one, I dont believe that the magnetic field is only contained in the core of a toroid transformer/inductor.  My view of it is that the mag fields of the windings engage the core cutting across the hole in the middle of the core, thus cutting any other windings that also go through that hole..  And my view is that most all of the interactions between the windings happen in the hole of the toroid core. Ive said it before many times as to what i think on this stuff and nobody has presented any evidence to get me to think otherwise other than 'conjecture'. So maybe you have some proofs that can 'prove' me wrong as you are that one stating that the field only exists in the core.


"EMF is measured in volts--has nothing to do with current."

I get what you are trying to convey with that statement. What you are trying to say is that a changing magnetic field on a wire produces voltage in the wire and not causing moving currents in the wire of which could influence the voltages that we can read across that wire. E fields, right?  Show me proof.

Mags

Magluvin

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #19 on: February 23, 2018, 12:54:20 AM »
Oh, and also important: the voltage height of the back-EMF highly depends on coil design, and therefor, the current will only flow backwards if it reaches a voltage higher than that of the supply. If it doesn't then, by means of logic, you are right. But it usually is higher. Often a multiple of the supply voltage.
Also important is a clean cutoff of the forward pulse.

"Also important is a clean cutoff of the forward pulse."

That statement is key to getting the reversal you speak of. Im glad you stated it. ;)

I have gone over this before.  And I can agree that you have to have an absolutely clean cutoff in order to enable the possibility of an actual reverse current after cutoff.

Imaging this....  We apply input to the coil. Then we have a not so clean cutoff where a spark happens across the switch opening. That spark is part of the continued forward current I speak of.  So with an absolutely clean cutoff, the field collapse still generates a forward current, at first, but with the clean cutoff the self capacitance of the coil takes on the high voltage produced by the field collapse. Once it is peaked, it does a reversal like an LC resonator. Now when we had that clean cutoff, there was 'nowhere' for that voltage produced by the collapse to dissipate to other than the coil. So if you have an absolutely clean cutoff, and provide a path for the reverse currents to exit the coil after the forward current has peaked, then yes, you will have what you claim and I am in complete agreement with you that it can be had.

It would be a much easier conversation if you could show what you are doing to get the results you claim, as I can agree that it is possible you are getting reverse currents back to the source using a clean cutoff, but as to getting more back than you have put in, I cannot agree with that yet until you show it.

Ive been through this subject a lot over the years.  Im not here to claim that you are wrong, yet, because I dont know for sure what you are doing to get your results you claim.  Your statement of the 'clean cutoff' is where I have to agree with you 100%. But it is my contention that there is first a forward current in the coil before there is a reversal as you claim and it is not just only a reversal after the cutoff.  You can demonstrate this to yourself on any simulator as in a simulator a switch can give you that clean cutoff as you describe provided that in the sim your switch parameters can be set for infinite ohms when open. Then put the sim scope across the coil and you will see a forward spike and then the reverse spike..  And you can set up the circuit with a diode that can capture the forward spike and you wont see the reverse spike at all, demonstrating that the forward currents do happen firstly.  ;)

Can you show us what you have going on so we can understand it better? It would be easier on everyone. 

Thanks

Mags

dieter

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #20 on: February 23, 2018, 02:17:58 AM »
Glad you agree with me in that point, Magluvin.[/size]


It's a thought, a logical conclusion. There is no "circuit".


Ok, so let's say there is a reverse current flow.
It recharges the battery or helps the supply caps, right?


Now, isn't it simply logical, that when you put a low resistance in that back path, more energy will get trough and back to the supply battery than over a high resistance? Is 1+1=2? I really tried to explain this core feature, It is the exact opposite of conventional energy consumption theory.


@tinman, check your backend, your overunity coil (wich I never termed) may be deep in there - so much about zynicism. :P


Again Magluvin, I probably would do this:


Use a Mosfet or NPN Transistor such as a Darlington TIP122 to open and close the Exit of the coil. So you could use some Signal Generator with squarewave, frequency and PWM to search for sweetspots. From Emitter to Collector goes a high power, fast Schottky Diode. Transistors break trough reversly at -12vdc, actually a zener effect, or may get fried, so this flyback diode allows reverse current, while the transistor inhibits forward when base=0vdc. Darlingtons give you a steep on and off curve, the tip122 amplifies current from the base by 1000x, so no problems to fully open that one with a few mA signals. Although, not a high frequency transistor, may work up to 1000hz.
So this is what's at the "Back End" of the coil, the side towards ground.
At the front end of the coil are similar Schottky diodes, an Avrabmenko Plug ( or however that is spelled), which redirects reverse current to a separate path. So one Diode for the juice from the supply to the coil, and the other one from the same coil front end to the experimental load and the to the supply.


Certainly, you need powerfull pulses and a huge coil to drive a significat load.


This is just one possible approach. But the Theorem stands by its own, simply because it's logical.

tinman

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #21 on: February 23, 2018, 10:06:57 AM »
 author=Magluvin link=topic=17611.msg517033#msg517033 date=1519341893]
 


Quote
I get what you are trying to convey with that statement. What you are trying to say is that a changing magnetic field on a wire produces voltage in the wire and not causing moving currents in the wire of which could influence the voltages that we can read across that wire. E fields, right?

No,not saying that at all.

Im saying it is the electric field that induces an EMF across a wire--not the magnetic field.

The magnetic field is a bi-product of current flowing through a conductor--no current--no magnetic field-->but still an EMF  ;)

Quote
For one, I dont believe that the magnetic field is only contained in the core of a toroid transformer/inductor.  My view of it is that the mag fields of the windings engage the core cutting across the hole in the middle of the core, thus cutting any other windings that also go through that hole..  And my view is that most all of the interactions between the windings happen in the hole of the toroid core. Ive said it before many times as to what i think on this stuff and nobody has presented any evidence to get me to think otherwise other than 'conjecture'. So maybe you have some proofs that can 'prove' me wrong as you are that one stating that the field only exists in the core.

It is my belief that the B field is confined to the core.
A secondary winding,where the windings pass through the middle of the toroid core-well away from the core it self,will have an induced EMF from the electric field-not the magnetic field.
When a load is placed across this secondary winding,a current starts to flow through this winding,and only then is a magnetic field produced around that secondary winding.

Can i prove this-->sure can.

Fore many years now,all seem to believe that the magnetic field is a must have,in order to produce current flow.
I say the magnetic field is a Bi-product of current flow,and an impedance on our electrical systems.

It is my belief that if we could remove this magnetic waste,then we would open up a whole new can of worm's-so to speak.

But problem is,we have had this drummed into us for the past 200 years,and we know no other way-->why,because we have not been looking--everyone is happy with the way thing are--how they have been told it is.


Brad

Magluvin

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #22 on: February 23, 2018, 11:47:39 AM »
Have to get to work. Ill reply to this one later today. Its not a short reply.

Mags

dieter

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #23 on: February 23, 2018, 12:09:08 PM »
Quote
The magnetic field is a bi-product of current flowing through a conductor--no current--no magnetic field-->but still an EMF  [/size]


I have a slightly diffrent understanding of this particular issue:


Once the current is actually flowing trough the inductor, the magnetic field is only trapped, but it us it's built up while the current started trying to flow, due to the voltage, but actually flew "into" the magnetic field, and not over the dc-resistance of the coil to ground. Current is converted to a magnetic field. The magnetic field holds a certain amount of energy this way. No surprise that when this field vanishes due to Pulse end, this change of magnetic field strength induces current in the very same coil, although in reverse direction.
This corresponds to the fact, that voltage is immediately there trough the entire coil, but current flow starts at zero and, depending on inductance and impedance, takes some time to rise up to what flows under a dc condition. For instance, if you have a transformer, the primary is at 220vac hot wire, but not connected to the neutral line (turned of by a switch, while hot wire and neutral by mistake swapped, so there is no current flow in the primary, you still can measure the Voltage at the secondary.


So I'd say the magnetic field is not a Biproduct of current flow per se, it is more like a mandatory depot that the current must only initially provide, in order to flow at all. This Depot however is not neccessarily lost - normally it just flows back to the supply. The voltage of the reverse current depends on the coil architecture, not the supply, as does the duration of this back "pulse".

dieter

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #24 on: February 23, 2018, 12:43:17 PM »
And about the use of the term "Back-EMF", the reverse current of a collapsing field, as well as the inductive impact of a secondary field like in a motor (Lenz Drag etc.) it's both the same thing, only the cause is a diffrent one. Back- electromotive  force simply means, a force that drives the current in the opposite direction, not neccessarily against a forward current.

tinman

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #25 on: February 23, 2018, 02:23:59 PM »
 author=dieter link=topic=17611.msg517053#msg517053 date=1519386197]

And about the use of the term "Back-EMF", the reverse current of a collapsing field

No-that is not BEMF-->that is inductive kickback,or flyback as some call it,and the current flow is in the same direction as it was when connected to the source.

as well as the inductive impact of a secondary field like in a motor (Lenz Drag etc.) it's both the same thing, only the cause is a diffrent one.

No,they are not the same thing at all.

,
Quote
Back- electromotive  force simply means, a force that drives the current in the opposite direction,

Wrong again.
BEMF is the self induced EMF an electric motor produces.
The lower the BEMF value,the higher the value of current an electric motor will draw.
The higher the BEMF value,the lower the value of current the motor will draw.

And what makes this harder,is bullshit like this
https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Counter-electromotive_force.html--> For example, the voltage drop across an inductor is due to the induced magnetic field inside the coil.[1][2] The voltage's polarity is at every moment the reverse of the input voltage.

What a crock of shit that is.
The CEMFs polarity is the same as the sources polarity--not bloody opposite/reverse.
If it were opposite,then we would have a huge current draw as soon as we attached the source voltage.Just take two 1.5 volt batteries,and connect them so as the negative of one is connected to the positive of the other,then connect the remaining two end to each other--so connect the two batteries in series-->then see what happens.

Only when the source EMF is disconnected,do we get a reverse voltage across the coil,as the field is now collapsing.

No wonder so many people have a hard time trying to work all this out,when you have idiots posting shit like that on websites all over the internet.

dieter

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #26 on: February 23, 2018, 04:04:20 PM »
Au contraire, Brad.


Look: When a coil attracts a magnet and thebmagnet gets closer, it's increasing fieldstrength seen from the coil causes inductive coupling that is REPULSING the coil, as Lenz's law holds true. So, to oroduce attraction in a coil you need one polarity, to oroduce repulsion you need thr other polarity - in the same one coil. No matter whether the current is induced via Lenz Law or simply by wires attached.
Once these two current directions fight afaonst eachother in the coil, of course, this means increased RESISTANCE for the current that comes from the wire, and hence, as you stated, less current draw, WHILE THE MOTOR SLOWS DOWN and to maintain the RPM and torque, you will need to increase the Power from the supply to the coil.


This isn't so much about you being wrong, but much more about a somewhat pathetic attitude to jump in and call people idiots, "proofing" that every word they say is wrong while diverging from the thread subject.


If such a mood issue is something infective around here, then I am seriously concerned about this forum.

citfta

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #27 on: February 23, 2018, 06:06:34 PM »
Dieter,

If you will read all the way through the following thread you will understand that the current does NOT reverse when the field collapses.  And the proper term is inductive kickback NOT back EMF.  There are many of us on this forum that have many many hours of research time on our benches.  As Brad has been trying to tell you your ideas are not supported by the test results.  This thread will help you get a better understanding of coil inductance and field collapse.

http://overunity.com/16203/inductive-kickback/#.WpBI2rNG3IU

Respectfully,
Carroll

tomd

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #28 on: February 23, 2018, 10:14:37 PM »
This article explains clearly the effects of a collapsing magnetic field.
First you have the emf/current (in the direction of the original applied voltage source) induced from the collapsing magnetic field.
Second as a result of the current from the collapsing magnetic field there is a cemf against the direction of the induced emf and therefore against the original voltage source.

"Finally, the applied voltage is removed--made to equal Zero (Vapplied = 0 volts); the steady-state Magnetic Field now starts to collapse, which induces an E.M.F into the inductor thus causing a Current to flow (of the same polarity as that of the original applied voltage source). As in the applied case there is a Counter E.M.F. generated by the Current generated from the collapsing Magnetic Field, again impeding the collapse of said Magnetic Field."

http://www.williamson-labs.com/480_rlc-l.htm

tinman

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Re: Back-EMF Manifesto - A Key, hidden in plain Sight.
« Reply #29 on: February 24, 2018, 12:09:22 AM »
This article explains clearly the effects of a collapsing magnetic field.
First you have the emf/current (in the direction of the original applied voltage source) induced from the collapsing magnetic field.
Second as a result of the current from the collapsing magnetic field there is a cemf against the direction of the induced emf and therefore against the original voltage source.

" As in the applied case there is a Counter E.M.F. generated by the Current generated from the collapsing Magnetic Field, again impeding the collapse of said Magnetic Field."

http://www.williamson-labs.com/480_rlc-l.htm

Quote
Finally, the applied voltage is removed--made to equal Zero (Vapplied = 0 volts); the steady-state Magnetic Field now starts to collapse, which induces an E.M.F into the inductor thus causing a Current to flow (of the same polarity as that of the original applied voltage source).

No
When the applied voltage is removed,the collapsing !magnetic ?! field induces a voltage across the coil that is of the opposite polarity to that of the source voltage.
The current will continue to flow in the same direction.