The bifilar pancake coil at its resonant frequency
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Author Topic: The bifilar pancake coil at its resonant frequency (Read 191720 times)
Re: The bifilar pancake coil at its resonant frequency
Quote from: TinselKoala on April 19, 2017, 11:37:25 PM
Itsu, It looks like you are getting very close to having the same resonant frequency on both "primary" and "secondary". I don't know what the result would be when you get them perfectly matched; in DRSSTCs it results in maximum power transfer between the coils, I think.
It would be very nice to be able to look at these things with a Spectrum Analyzer. Our scopes can probably do limited FFT analysis (mine can but it really sucks) that would be helpful but my scope's FFT function, even when working well, is a poor substitute for a genuine Spectrum Analyzer. Maybe that's why really good SAs often cost more than a house and car put together. I wonder if anyone posting experiments here has access to a proper SA.
Mags, why is this "unflattering comparison" photo, which is nothing more than TOS violation, personal attack and childish insult, allowed to remain in view?
Synchro is now on moderation,until he stop's all the crap.
TK, Gyula,
thanks, good suggestions, i will look at it with my (not so expensive) SA and make both coils variable (capacitance).
I think i will first need to make myself an identical TBP coil so they are already closely matched, then some variable caps (i have these
2 big 45-450pF variables) would be enough to line up their resonance points taking care not to overcouple the coils.
synchro1
Nelson, I'm glad we agree on this basic algebra.
And now we are beginning to see where synchro has gone off the rails. He clearly doesn't get that the Inverse is not the Negative. X-1 is equal to 1/X, not some negative value. And the H (scalar unit of induction) of the Henry is not the same as the H (vector quantity)of the magnetizing field strength. He apparently has confused these two very different things in his mind, because of the use of the same letter for both. But the H of the field strength is a letter chosen at random by Lord Kelvin in 1850, and has nothing to do with the assignment of the name Henry and the letter H as abbreviation for the unit of inductance.
For Synchro: When letters are Bolded like that it is not done for emphasis. It is a common way to indicate that the quantity referred to is a _vector_ not a scalar. But I don't expect you to understand the difference, since the math is obviously over your head. You should however be capable of clearly understanding that the "H" of inductance is not the same thing as the "H" of magnetic field strength. Or am I giving you too much credit?
@Tinselkoala,
"A negative correlation means that there is an inverse relationship between two variables".
K is the letter from Kelvin.
Its SI derived unit is the henry (the same as the unit of inductance, although the two concepts are distinct).
I told you the negative Henry was a measure of a magnetic field, now you're trying to teach me my lesson back.
TinselKoala
« Reply #1068 on: April 20, 2017, 12:29:36 PM »
Quote from: tinman on April 20, 2017, 10:38:46 AM
He has just taken the insults and "vendetta" (his word) against me over to EF. He isn't going to stop.
But thanks.
I wouldnt worry to much about the Energetic forum to much TK,as we know what that forum is all about $$$$$$$$$$$$$$$$$$$$$$$$$$$$
I will approve synchro's posts,as long as there not direct insults toward fellow members.
Resonance is an interesting subject, we are informed of it being a single frequency phenomena.....blah blah blah.... if we were to really align ourselves with the core message, Tesla's, we would be trying to establish this condition each time the inductance opposes change! (this is when you are supposed to get up and dance....) This is new territory, uncharted, here who gives a shit about the single sine frequency as it relates to self induction and capacity of the system at the make, and at the break.....it does not apply, hell, capacity and self induction themselves are not what we are taught they are at these key instances! I have been saying this forever, FUCK SINGLE FREQUENCY RESONANCE CONCEPTS! You people keep listening to the wannabe authorities and are missing the damn point!
Why is it so difficult to stick with what is right in your face....not a question.....fuck a charge....acknowledge and respect the induced and its relation to both self induction and capacity!
You all read the patent....good....you all studied the patent....great...but you are taking it at face value....not good...he gave you a capacitor, that is so fucking obvious....HELLO!!! But not just any capacitor, this one is off the fucking chain. Tesla was a master at misdirection, as soon as he gives you a holy shit moment, while he has your undivided attention, he immediately fucks you by instructing you to make a connection between the two plates, he sings you a lullaby, that's right, he sings your lazy asses to sleep as he elaborates on how fascinating the connection is and how you gain proximity stress.....you take his word for it, wire the capacitor up and operate it like the inductor that it became......you do what he says because hey...it's Tesla...stupid....
As is, the coil is to be operated in an AC system. The coil as it should have been presented would be operating in a pulsed DC system or an interrupted AC system. Self induction, capacity and frequency are all related....till they aren't.... We are trained to limit them, they (the aforenamed) don't receive this training.... The LC you are looking for is series, but not for the reasons you are suggesting. You do not want to neutralize the self induction ( but Tesla said....LOL.....) you want to neutralize the "negative" effects associated with self induction...lemme grab a straw or two here.......current limiting....maybe....that ties into time constants...maybe....
Energy in an Inductor
"When power flows into an inductor, energy is stored in its magnetic field. When the current flowing through the inductor is increasing and di/dt becomes greater than zero, the instantaneous power in the circuit must also be greater than zero, ( P > 0 ) ie, positive which means that energy is being stored in the inductor.
Likewinse, if the current through the inductor is decreasing and di/dt is less than zero then the instantaneous power must also be less than zero, ( P < 0 ) ie, negative which means that the inductor is returning energy back into the circuit. Then by integrating the equation for power above, the total magnetic energy which is always positive, being stored in the inductor is therefore given as":
A Pint is a Pound the World Around:
No it isn't! Some impudent smug snorts. No two things can be the same. We're constantly bombarded by such preposterous inanities.
A pint is equal to a pound in weight. 1 Coulomb is equal to 1 Gauss of magnetic force.
Negative values such as Henries of inductance or current in Ampere's have negative values on our measuring instruments we're forced to assign values to.
A negative Henry is a measure of magnetic force. Negative current is measured as equal to positive current simply moving backwards. These are positive values expressed in the negative range; Not imaginary terms.
Energy stored by an Inductor:
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Quote from: tinman on April 20, 2017, 12:35:06 PM
You might also try to prevent him from posting obviously incorrect "math" and spin. Like what he just posted up above, making the error about a negative correlation. An inverse relationship between variables does not mean one of them is negative or an inverse. He is over his head with even basic algebra and he is still going on and on trying to salvage his false claims about units being equal when they aren't, and the "negative Henry" when he probably means the Inverse Henry H-1 which of course means 1/H NOT -H.
He cannot justify his bogus math and units relationship claims by a posting a proper chain of mathematical expressions, because the claims are false. Making false claims is a violation of the Terms of Service of this forum, and carrying on a "Vendetta" against me is also a violation.
Magluvin
Quote from: MileHigh on April 20, 2017, 06:17:52 AM
Ignoring the speed of light, it's instantaneous. However, just because there is 50 volts between two adjacent conductors and there is a measurable transient distributed capacitance between those two conductors does not mean that there is instantly an excess negative charge on one conductor and a lack of negative charge on the other conductor. Any charge displacement to charge this transient capacitance would still have to flow in the form of current by snaking its way through the spiral conductors, and that means you encounter an inductance to overcome again and the energy to do that has to come from somewhere. At the same time, the electric field is starting to push current through the coil in a conventional sense and slowly energizes the inductor. It's very complicated with multiple things going on at the same time and in the realm of supercomputer simulation.
One part of the problem is that the bulk of the electric field flux is snaking its way through the coil and is pointed in the direction of the coil. That electric field might manifest as a measurable potential on the surface of a conductor, but it is at right angles to any electric field that would be associated with the transient distributed inter-winding capacitance.
I don't know why you want to believe that there is some "hidden magic trick" associated with a bifilar pancake coil. What Tesla says in his patent is certainly about the reactance of the capacitance cancelling out the reactance of the inductance at resonance. There are probably about 50 YouTube clips out there that explain this with phasor diagrams. Phasor diagrams are more intuitive than hard mathematical analysis and you should check them out.
"I don't know why you want to believe that there is some "hidden magic trick" associated with a bifilar pancake coil."
Well I believe it is with bifi in general, not just a pancake coil.
Ive heard through the grapevine yest that there may very well be a rabbit in the hat that may just come here very soon. Wait for it.... And Im also feeling real good about another possibility that may be even stronger in evidence of the specialty of the bifi coil. Wait for it.....
Also, on my theory, like you said its complicated, so rather than completely refute my idea, lets let testing do the talking. I wont go further into it until I am ready to do the testing. I will describe the test before I do it and variations of which may produce different outcomes. Wait for it....
Once again.... the INVERSE Henry 1/H, or H-1, is a measure of magnetic reluctance. It is not a "negative Henry". It is not the same thing as H, even with a negative sign, which is a vector quantity representing the strength of the magnetizing field. The letter H for this field strength was chosen by Lord Kelvin in 1850, probably at random, along with his choice of B. This is not the same thing as the Henry, the unit of inductance. Inductance is NOT THE SAME as field strength, they have different units and one is not the negative or even the inverse of the other. You can see for yourself that Amperes/Meter, the units of the H field, do not appear anywhere in your listing of units for the Henry, not even negative OR inverse.
A negative correlation has nothing to do with "negative Henry" nor does it imply that one or the other of the correlated variables is "negative". By posting what you have posted you reveal that you do not understand correlation or inverse relationships.
In 1850, Lord Kelvin, then known as William Thomson, distinguished between two magnetic fields now denoted H and B. The former applied to Poisson's model and the latter to Ampère's model and induction.[9] Further, he derived how H and B relate to each other.
The reason H and B are used for the two magnetic fields has been a source of some debate among science historians. Most agree that Kelvin avoided M to prevent confusion with the SI fundamental unit of length, the Metre, abbreviated "m". Others believe the choices were purely random.[10][11]
https://en.wikipedia.org/wiki/Magnetic_field#B_and_H
Note the graphic below. Nowhere is a "negative number" used or implied. Negative correlation means as one variable increases the other decreases, and positive correlation means as one variable increases, the other does as well, and when one variable decreases the other variable decreases too. It has nothing to do with negative values of the variables. The _slope_ of the regression line is either positive (positive correlation) or negative (negative correlation).
You really must stop posting your basic math errors and misconceptions.
Pos-neg_correlation.PNG (13.16 kB, 600x250 - viewed 374 times.)
Quote from: synchro1 on April 19, 2017, 02:59:49 PM
@nelsonrochaa,
Thanks for the clarification. Consider this:
"Ørsted discovered the connection between magnetism and electric current when a magnetic field produced by a current-carrying copper bar deflected a magnetised needle during a lecture demonstration".
"In the CGS system, the unit of the H-field is the oersted and the unit of the B‑field is the gauss. In the SI system, the unit ampere per meter (A/m), which is equivalent to newton/weber, is used for the H‑field and the unit of tesla is used for the B‑field".
"H is measured in units of amperes per meter (symbol: A⋅m−1 or A/m) in the SI. B is measured in teslas (symbol: T)".
This is what you need to understand: The H field is an electrical equivalent and the B field a magnetic one.
You see fit to lecture me on the H and B field?
https://www.youtube.com/watch?v=u6jBtZ4VPC4
all 6 bif. pancake coils are the same resonance frequency
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YTR2.JPG (66.78 kB, 940x736 - viewed 343 times.)
MileHigh
Put your phasors on spin....
When a magnet approaches a coil, a current runs in one direction and the ammeter registers a plus indicating a positive current. When the magnet's pulled away from the coil, the current runs in the opposite direction and the ammeter registers a negative indicating a reverse or negative current.
Lenz's law.png (12.08 kB, 233x185 - viewed 120 times.)
Here we see the negative Henry value on the left, in the "Magnetic Reluctance" equation below. This value is the equivalent of Ohms in the resistance formula on the right and is a measure of magnetic field strength. Naturally, everyone knows the field resists change in current through an inductor and therefore behaves like resistance in the other formula.