The bifilar pancake coil at its resonant frequency

[Magluvin]

Wouldnt it be better if we look at the differences between the single wound pancake coil,and the bifiler pancake coil,and see if we can work out what those differences mean-or how they would change the operating characteristics of the coil.

Lets say that each coil(1x single wound,and one bifilar wound)has 100 turns in total,and we pulse each coil with a 100 volt potential across each coil--what ever frequency.

Now,as far as i know,the single wound coil would have 1 volt potential difference between each winding--although i believe that the potential difference between the windings at the center would be less than 1 volt,and increase between windings as you get toward the outer windings.


But,with the bifilar coil,the voltage between windings will always be 50 volts.
So,i see one coil with an uneven voltage between windings,and the other with an even voltage between windings.

So,what dose this mean ?
If each winding is seen as the two plates of a capacitor,and one coil dose not have an even voltage between winding,and the other dose-how would the stored capacitive energy stack up between the two?

Then there is the magnetic field--how would it differ between the two?
Dose the voltage potential between windings play any part in how the magnetic field will propagate around those windings,and that coil as a whole ?.


Brad

In response to your last post to me.....

It took me some time to figure that one out and even though I know it well now, im still thinking about how we can take advantage of the bifi situation.

The difference between having 1v difference between adjacent turns and having a 50v difference should be a huge alteration of how the capacitance reacts for each.

And I would think that the most notable effect would be that the bifi capacitance would react much faster to accepting an immediate input than the monofilar winding mostly for the reason that a 50v difference between each turn should have a much greater capacitive attraction between the 2 charges than would only a 1v difference. Thats how I see it and Im sticking to it. Like if instantaneously the 50v difference appears between each turn, how does that compare to 1v between each turn?

Tesla says in the pat  that the bifi coil will accept an input and ignore the coils induction and will only be impeded by the resistance of the coil a a whole. Read that again and let it sink in. It very possible that looking into the resonance aspect of the bifilar is not the right direction here, but disruptive discharge pulsing is the way to go.

What that tells me is that the bifi winding should accept an input 'pulse' to full resistive currents without delay of inductive impedance.  I have to interpret that as the bifi will have a max mag field immediately. A super charged field build in a modifed(bifi vs monofi) coil that the normal coil cannot do.  So I guess that if we can make a magnetic field build at much much higher speeds than a normal winding, then maybe we can take advantage of that with a secondary. So now we would have to look at how a pickup coil or a literal secondary would react to that kind of magnetic impact.

We can just about do that with a very tiny inductance, say maybe a 3 turn primary made of 10ga for example.  So in that situation, we pulse the pri and we use a lot of current to produce that near instantaneous field build to cut the sec.  So if we have a 100 turn coil with say a resistance of 1.4ohm(a real example I just posted earlier ) and we monitor the field build with a pickup coil, the field will build over time giving a gradual induction to the pickup till max pri current. But a 100 turn bifi should, according to Tesla should reach full max mag field build, instantaneously. And we should be able to detect that with a sec or just a pickup coil. Would that produce ou? Dunno yet. Guy was a frikin genious to even come up with such a thing and work out the nature of it. A human oscilloscope he was.

So the 3 turn 10ga at very sub ohm levels and very small inductive impedance vs 100turns of 18ga at 1.4 ohm bifi that reacts with 0 or say even near 0 inductive impedance and many turns with a field build that is faster than the 3 turn winding, which one would be more eff at inducing the sec? Crazy stuff.

So a regular and bifi of 100 turns actually have the same physical capacitance between each turn, but the effect of the voltage difference between each turn should magnify the capacitive attraction between each turn and attracting input, what, 50 times in the example?

Lots to think and do with all that....

Maybe an improvement would be using flat conductors to increase capacitance and reduce resistance and still have a compact coil. Tito had suggested producing a mag field with a capacitor, and maybe thats it.



Mags

[tinman]

@Tinman,

Here's a diagram of positive and negative current traveling in the same direction. The "Negative Current" is represented by the green colored upside down curve below the zero line:

Maybe this will help you understand synchro.

[Magluvin]

Sure, I made a mistake, but I certainly didn't make it on purpose.

But is funny. I know you consider yourself to be well above me in all this stuff, yet I can recognize an approximate coil resistance just by looking at it in a vid without proper perspective. If you are going to stand as an authority on these things here then I would expect the same kind of prowess as I had shown here. Sure you can lay it down and say it was a mistake, but at the time you were laying it down as if it were textbook example of what is going on in conrads coils. You resistance number was so far off that it made a uh and pf coil to look like the outcome was more than 200% worse than it actually is. Thats a big mistake, not a little tiny baby mistake. So its just hard to not think that maybe you are making these changes on purpose for your own benefit at degrading the experiments here. Sorry but as you know, this is not the first time for such mistakes of this sort.

mags

[Magluvin]

When you are talking about a conventional transformer with a core, then the differences are essentially going to be zero.  There is no logical or rational reason for there there to be any real differences.  It doesn't matter if the windings are separate or side by side or on opposite sides of the core.  The primary winding will pump almost 100% of its flux into the high-permeability core irregardless of if the secondary winding is separate from it or inter-meshed with it.  Likewise the only thing that the secondary winding cares about is the fact that it sees changing flux through the core that it is wrapped around.

It sometimes blows my mind how people can't seem to work these things out in their heads by applying their knowledge.  It seems so many people chase after imaginary things like some sort of fairy tale superstition.  It's the same deal with the series bifilar coil, pancake or otherwise.  They are almost indignant that you pose questions about it's application and practicality.  Yet, so far, it seems nobody can actually answer these questions.

So far I have only really put effort into possible resonance of the bifi, that seemed to be the logical possibility considering all the resonance talk associated with them.  I have not concentrated on cap discharge int a bifi or the possible diff of a normal pri/sec vs bifi pri/sec. So that is all just a next step.

Mags

[tinman]

In response to your last post to me.....

It took me some time to figure that one out and even though I know it well now, im still thinking about how we can take advantage of the bifi situation.

The difference between having 1v difference between adjacent turns and having a 50v difference should be a huge alteration of how the capacitance reacts for each.

And I would think that the most notable effect would be that the bifi capacitance would react much faster to accepting an immediate input than the monofilar winding mostly for the reason that a 50v difference between each turn should have a much greater capacitive attraction between the 2 charges than would only a 1v difference. Thats how I see it and Im sticking to it. Like if instantaneously the 50v difference appears between each turn, how does that compare to 1v between each turn?

Tesla says in the pat  that the bifi coil will accept an input and ignore the coils induction and will only be impeded by the resistance of the coil a a whole. Read that again and let it sink in. It very possible that looking into the resonance aspect of the bifilar is not the right direction here, but disruptive discharge pulsing is the way to go.

What that tells me is that the bifi winding should accept an input 'pulse' to full resistive currents without delay of inductive impedance.  I have to interpret that as the bifi will have a max mag field immediately. A super charged field build in a modifed(bifi vs monofi) coil that the normal coil cannot do.  So I guess that if we can make a magnetic field build at much much higher speeds than a normal winding, then maybe we can take advantage of that with a secondary. So now we would have to look at how a pickup coil or a literal secondary would react to that kind of magnetic impact.

We can just about do that with a very tiny inductance, say maybe a 3 turn primary made of 10ga for example.  So in that situation, we pulse the pri and we use a lot of current to produce that near instantaneous field build to cut the sec.  So if we have a 100 turn coil with say a resistance of 1.4ohm(a real example I just posted earlier ) and we monitor the field build with a pickup coil, the field will build over time giving a gradual induction to the pickup till max pri current. But a 100 turn bifi should, according to Tesla should reach full max mag field build, instantaneously. And we should be able to detect that with a sec or just a pickup coil. Would that produce ou? Dunno yet. Guy was a frikin genious to even come up with such a thing and work out the nature of it. A human oscilloscope he was.

So the 3 turn 10ga at very sub ohm levels and very small inductive impedance vs 100turns of 18ga at 1.4 ohm bifi that reacts with 0 or say even near 0 inductive impedance and many turns with a field build that is faster than the 3 turn winding, which one would be more eff at inducing the sec? Crazy stuff.

So a regular and bifi of 100 turns actually have the same physical capacitance between each turn, but the effect of the voltage difference between each turn should magnify the capacitive attraction between each turn and attracting input, what, 50 times in the example?

Lots to think and do with all that....

Maybe an improvement would be using flat conductors to increase capacitance and reduce resistance and still have a compact coil.



Mags

Well,guess i am going to have to wind a couple of pancake coils now-1x mono,and 1x bifiler.

Tito had suggested producing a mag field with a capacitor, and maybe thats it.

All the caps i have pulled apart,have the input taps at the center of the rolls of plates,and so,the current will flow CW around half the windings of each plate,and CCW around the other half of each plate. This would cancel out any magnetic field--maybe that is why they make them like that.


Brad