Confirming the Delayed Lenz Effect

[Magluvin]

MH may be right about the coil resistances reading the same in the SB configuration. I have to test that myself.

I have a coil I wound way back as a bifi. I didnt know what I was doing with it then. I went to get it out the other day and one of the leads coming out near the core was broken off. I have to unwind it to fix. 

But that coil was strange when it came to measurements. Capacitance checking was the real weird one. Measuring capacitance across one of the windings, meaning a winding from end to continuity end measured 1uf. Measuring capacitance between the 2 open windings was about 11nf if I remember correctly.  These coils will mess with your mind.

I also had an idea a while back using a bifi secondary connecting opposite open ends to a bridge rectifier. If an AV plug can pull from a single ended open secondary into a cap, using the bifi's open ended to a bridge might be interesting. The connection in the transformer between the 2 windings will be capacitive.  Just ideas.

Mags

[Farmhand]

From what Im just beginning to understand more recently is that the SB in Teslas pat is intended as an electro magnet, and that when input is applied, the capacitance increase 'within' the coil neutralizes the self inductance of the coil so current flows much faster right from the start thus producing a stronger magnetic field.  After all, the output property of an 'electromagnet' is a magnetic field. So the objective is a stronger magnetic field.

MH may be right about the coil resistances reading the same in the SB configuration. I have to test that myself. But the initial field production is much quicker from the beginning because currents flow much quicker due to the 'internal' capacitance. We cannot compare that to just adding a capacitor to a coil ad call it the same. A normal coil is going to take in what its given as the impedance allows over time.

In the case of the nail with wire wound on it, if there is more capacitance within the bifi coil compared to the normal wound nail, then the SB nail could result in more field due to this current input rush as compared to the impeding, slower building, normal coil.

It is said that if you attach a magnet to a metal bar and measure the holding strength before release right away as compared to leaving the mag on the metal for a longer period of time, the one that was there the longest will have the stronger hold. So if the inrush of the bifi is stronger initially than the normal coils full current, then the nail could have a stronger field even once the SB coil settles to full constant current flow. Especially if there are metal objects to be picked up added to the end of the core(nail) 'initially'.

I would imagine that 'if' the sb coil can pick up more staples or paper clips well after the sb coil is connected to the battery, then it should pick up even more if the nail is already in contact with the staples before the current is applied. This is just my thoughts on it before doing tests.

And then there is the indisputable lowering of resonant freq with the added capacitance that is what I am interested in also.

Then there is their use in a transformer. What would be the effects if the capacitance is built into the coil(in the transformer) rather than external? I have a n ecore prepped for my home made litz winding I will be making this weekend to see. The litz will be made with 7 strands stretched out between 2 mixing sticks and then then slowly twist the stick on one end til it is wound into one wire. And all the ends will be ready for capacitance readings to get things as balanced as possible. And a 7th strand to test out shorting  along the way. So testing of the sb in the transformer as a primary and as a secondary will be done.

Mags

I'm not so sure about that, if we add a capacitance to a coil it will keep much the same resonant frequency when fed different voltages, going by what I can gather the SBC
will change it's resonant frequency with voltage changes. But I don't know this for certain. A coil that lowered it's resonant frequency as the applied voltage is increased would be useful for sure. But a SBC fed with 12 volts at it's resonant frequency say 10 kHz, should act in a similar way magnetically to a normal coil with the same amount of wire and fed with 12 volts at 10 kHz and tuned with a capacitor to be resonant at 10 kHz. I would say the effect of the self capacitance cancelling the inductance would be the same as an added capacitance cancelling the self inductance, which is common practice.

The difference between 260 kHz and a few mHz is a lot. If the turns can take the strain then it's all good. Need to test the difference in the resonant frequency of an SBC fed with say 1 volt as compared to 100 volts. Frequency could remain fairly stable, I've never tested it and wouldn't bother to try to work out how to calculate it then test it anyway.

I don't have a simple way to pulse a coil with 100 volts at 260 kHz on hand. Edit: Well actually I do, but it could make smoke without loading the coil. I can open the window and blow the smoke out I suppose.  If I do it I'll be sure to film it in case there might be a spectacular failure..

Cheers

[synchro1]

on 5/17/04 11:11 PM, David Thomson at yahoogroups@... wrote:

My research on bifilar windings indicate magnetic field is the primary purpose of the coil. The origional patent calls the bifilar coil, a coil for electromagnets. My readings indicate that the size is of primary importance as the strength of the field is squared with each doubleing in size of the coil. There is no reason that I am aware of that the flat coils cannot be stacked like pancakes. The flat coils could also be placed over a cone shape so they would assume a cone shape. The coil more than likely acts like a condenser found in old cars. The magnetic field created by one wire, acts to create resistance to the electricity flowing through the second wire.
Paul

The "Oldscientist" measured 40x less inductance and half the Ohms in a Tesla series wired bifilar compared to a single wire coil of equal gauge and length. The Tesla bifilar also produces twice the magnetic field, as proven by "Tesla-Coil-Builder". "Magnetic field is the primary purpose of the coil". This major point grows overshadowed by discussions concerning the bifilars other unique characteristics and diverse applications, and needs re-emphasis.

[Farmhand]

Well I haven't seen the Old Scientists video so I can't comment, he might be confused. He might have meant to say four times as much inductance.

Anyway this is words from the patent.

Clearly it's not just for spiral coils, it was probably just easier to show with spirals for the diagrams. The words are clear I don't see how that can be disputed.

Lines 33 to 38 of Page one.

I would here state that by the term coils I desire to include generally helices solenoids or in fact any conductor the different parts
   of which by the requirements of its application or use are brought into such relations with each other as to materially increase the self induction found that in coil there exists

Another clear statement if the coil already has sufficient capacity for the working frequency it's good to go, also if the coil can be made to have sufficient capacity by some other method it is good to go also.

Lines 50 to 57 of Page one.

It is well known that the higher the frequency or potential difference of the current the smaller the capacity required to counteract the self induction hence in any coil however small the capacity it may be sufficient for the purpose stated if the proper conditions in other respects be secured

And this indicates to me that the frequency of a Coil wound in such a way will decrease with an increase in the applied voltage.

Lines 67 to 79 of Page one.

In order to attain my object and to properly increase the capacity of any given coil I wind it in such way as to secure a greater difference of potential between its adjacent turns or convolutions and since the energy stored in the coil considering the latter as a condenser is proportionate to the square of the potential difference between its adjacent convolutions it is evident that I may in this way secure by a proper disposition of these convolutions a greatly increased capacity for a given increase in potential difference between the turns

I'm sorry but I'm not really interested in what you say some other guy said he measured or the conclusions the other guy came to.

If I do the measurements and mine differ I'll believe mine. I'm biased.

Cheers

[synchro1]

My discovery:


Four wires wraped together will wind a "Quadfilar coil". Wired as two Tesla serial bifilars, one pulsed D.C will invert the power to A.C. in the other, plus the "Q" coil doubles the pulsed D.C. to A.C. output voltage.