Resonance Effects For Everyone To Share

[gotoluc]

Hi Luc.

I was hoping you could use your meter to test your coil of speaker wire for me. I want to do some testing in PSpice with something that is in the ballpark of the type of coils you guys might be using. It will also come in handy later so we can compare notes. If you could measure the coil's inductance and resistance I would appreciate it, and so will you later on I think.

Any coil will resonate, you bet.

Are you familiar with the relationship of inductance to the no. of coil turns?

The length difference you noticed is most likely related to the number of turns achieved in the coil. Most of the time, with a longer length of wire, you will end up with more turns in your coil. More turns results in more inductance, which in turn results in lower Fres.

Resistance of the coil won't change the Fres, but it will affect how "tight" the tuning is of Fres. A higher resistance will make the tuning to Fres quite easy because it will have a broad gentle range in the area of Fres. A lower coil resistance will give you a much narrower range where Fres appears, but the resonant voltage will also be much higher than the case where the coil resistance was higher. The series coil resistance affects what is called "Q" of the resonant LRC tank. High Q gives higher voltages and tighter tuning, Low Q is the opposite.

I await your values. I'll try to create a diagram with similar symbols that Groundloop used, although I don't favour them too much LOL.

Again, coil values won't really affect the circuit, I just want a starting point I can use for simulation.

.99

Hi .99,

Okay, I understand but I don't have that roll of speaker wire anymore, so what I'll do is give you is the spec's of the coil I used in many of my videos, it is 105 turns of no. 21 AWG on a 3" diamiter spool and the wire take up 3-3/16" of space on the spool surface. It measures .525mH and the DC resistance is 1.19 Ohms.

I'm not familiar with the relation of Inductance increasing by the amount of turns. I thought Inductance was based more on the coil length. I'm going to have to test that more.

Is there a software that one could easily use to see these results without needing to make coils? that would be helpful

Thanks .99

Luc

[Inquorate]

For gotoluc

Electronics Calculators; bookmark for reference

Martindale's Calculators On-Line Center: Electrical Engineering & Computer Engineering: Section Sen-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Anim

Coil calculator

TESLA SYSTEM CALCULATOR

Free online electronic component value calculators

Ps, could you take a look at this gotoluc? I wonder how much of it is a resonant tank circuit simply cut in half by the intervening space between the halves..

http://www.energeticforum.com/renewa...xperiment.html

[poynt99]

Hi Luc,

Thank you for the specs.

Yes indeed, the inductance (L) of a coil is proportional to the number of turns squared. So this means if you double the number of turns, you will have 4 times the amount to inductance.

You could have a certain length of wire and make two coils, one that has a big diameter such that maybe you can only get two turns on it, and another that is significantly smaller in diameter which allows a few hundred turns, this last one will have quite a bit more inductance, even though both used the same length of wire.

Here's a link explaining the optimum dimensional ratios to make a coil and get the most inductance. It's called a "Brooks" coil.

An introduction to the air cored coil

As far as the software program, the only thing I know of is SPICE programs. I am not aware of something relatively simple out there, but I am sure someone else here would.

What kind of effects were you wanting to see with the program...similar to the type of things I'm showing? If so, then you will most likely need to use a SPICE program too, or something similar. As far as calculators etc, there are many as the above post indicates.

.99

[gotoluc]

Electronics Calculators; bookmark for reference

Martindale's Calculators On-Line Center: Electrical Engineering & Computer Engineering: Section Sen-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Anim

Hi Inquorate,

thanks for posting all the above links I saved this one in my online calculators as it's simple and easy to understand: Coil Inductance Calculator - 66pacific.com

Ps, could you take a look at this gotoluc? I wonder how much of it is a resonant tank circuit simply cut in half by the intervening space between the halves..

okay ... I had a look at it and it's not my style! I'm a hands on experimenter and trying to interpret someones written explanation is not for me. If only he had a video demo, then he would probably get my attention

Thanks for sharing my friend



Luc

[gotoluc]

Hi Luc,

Thank you for the specs.

Yes indeed, the inductance (L) of a coil is proportional to the number of turns squared. So this means if you double the number of turns, you will have 4 times the amount to inductance.

You could have a certain length of wire and make two coils, one that has a big diameter such that maybe you can only get two turns on it, and another that is significantly smaller in diameter which allows a few hundred turns, this last one will have quite a bit more inductance, even though both used the same length of wire.

Thanks .99 for the information

So now we know that two length of copper wire can have different Inductance values by the way it is coiled. We also know that a higher Inductance coil will resonate at a lower frequency! what else do we get with a higher inductance?... is the magnetic field of a higher Inductance coil any stronger then a lower Inductance coil even though both use the same length of wire?...
Will a higher Inductance coil store more energy? If so, would it create a stronger inductive flyback? Is there anything else you can think of the effects of more inductance has?
[/QUOTE]

Here's a link explaining the optimum dimensional ratios to make a coil and get the most inductance. It's called a "Brooks" coil.

An introduction to the air cored coil

Thanks, that's good info

What kind of effects were you wanting to see with the program...similar to the type of things I'm showing? If so, then you will most likely need to use a SPICE program too, or something similar. As far as calculators etc, there are many as the above post indicates.

I was thinking of a program that I would enter the data of a coils, turns layers, resistance, pulse frequency, voltage, period and it would tell me it's magnetic field strength, inductive kickback strength and so on and when I would be happy with the results I would build the real thing to test.

Anyways, I was just wondering

Thanks for your time

Luc

[sucahyo]

Here is what I use to get duty cycle from 50% to 1%, freq from 1Hz to 50Khz.

replace the 100ohm resistor with variable resistor and use available calculator for duty cycle and frequency. I mention 50KHz max because I think that is max of what 3055 and 2955 can switch.

[lamare]

Cymatic

Hi all,

I may be a bit offtopic, since this is more about EM resonance, but I recently came across "cymatic", which deals basically about sound resonance effects, which are really awesome, not in the least because these give you the possibility to visualise all kinds of phenomena which also occur with EM resonance phenomena.

Especially the research by Jenny is very interesting. Search on google video for "cymatic Jenny", and you'll find video's like these:

YouTube - resonance
YouTube - Cymatics - Bringing Matter To Life With Sound (Part 1 of 3)
YouTube - Cymatics - Bringing Matter To Life With Sound (Part 2 of 3)
YouTube - Cymatics - Bringing Matter To Life With Sound (Part 3 of 3)

[gotoluc]

Hi lamare,

I do agree that Hans Janny life work of the study of the physical effects of vibration is quite amazing.

I think in some experiences he was using a combination of frequencies to obtain some of the effects and maybe it would be worth experimenting to see the effects of two different resonating frequency inductors brought together to a third tuned collector inductor to see if anything interesting shows up. The combination's are endless

Thanks for sharing

Luc

[poynt99]

Thanks .99 for the information

So now we know that two length of copper wire can have different Inductance values by the way it is coiled. We also know that a higher Inductance coil will resonate at a lower frequency! what else do we get with a higher inductance?... is the magnetic field of a higher Inductance coil any stronger then a lower Inductance coil even though both use the same length of wire?...
Will a higher Inductance coil store more energy? If so, would it create a stronger inductive flyback? Is there anything else you can think of the effects of more inductance has?

Yes, all those things you mention are correct.

Magnetic field strength is proportional to the current through the inductor/coil (as you are already aware), and also the coil's inductance.

Yes, a higher inductance will store more energy because a stronger magnetic field is created around it. With higher inductance comes a stronger inductive kickback.

One important issue to always keep in mind though when trying to achieve more inductance in a coil, is the fact that you inevitably will use more wire. More wire means more total DC resistance in the coil, and it is this DC resistance that dampens certain effects and causes power dissipation.

Do you remember my big document on capacitor energy transfer experiments? I touch on the effects of coil resistance there because it has a direct impact on the efficiency of these transfers. Similar issues here with coil resonance and achieving high inductances.

Wind a coil with 1000 turns of 14 AWG wire vs. one with 30 AWG wire and see the difference in how the coil resonates. The heavy wire coil will have a much higher "Q" factor, and that means better voltage amplification at resonance!

One other note of interest with these HIGH-Q coils, is in order to keep them into peak resonance, your circuit which drives them must not drift too much in frequency, because high Q coils have a very high "selectivity" as well, which means the frequency band in which they resonate is quite narrow, so any change in frequency will have a large effect on the resonating voltage.

Anyway, enough of that for now. Let's see if I can make these coils resonate for you.

I assume that the coil specs you gave me were for an air-core coil?

.99

[gotoluc]

Yes, all those things you mention are correct.

Magnetic field strength is proportional to the current through the inductor/coil (as you are already aware), and also the coil's inductance.

Yes, a higher inductance will store more energy because a stronger magnetic field is created around it. With higher inductance comes a stronger inductive kickback.

One important issue to always keep in mind though when trying to achieve more inductance in a coil, is the fact that you inevitably will use more wire. More wire means more total DC resistance in the coil, and it is this DC resistance that dampens certain effects and causes power dissipation.

Do you remember my big document on capacitor energy transfer experiments? I touch on the effects of coil resistance there because it has a direct impact on the efficiency of these transfers. Similar issues here with coil resonance and achieving high inductances.

Wind a coil with 1000 turns of 14 AWG wire vs. one with 30 AWG wire and see the difference in how the coil resonates. The heavy wire coil will have a much higher "Q" factor, and that means better voltage amplification at resonance!

One other note of interest with these HIGH-Q coils, is in order to keep them into peak resonance, your circuit which drives them must not drift too much in frequency, because high Q coils have a very high "selectivity" as well, which means the frequency band in which they resonate is quite narrow, so any change in frequency will have a large effect on the resonating voltage.

Anyway, enough of that for now. Let's see if I can make these coils resonate for you.

I assume that the coil specs you gave me were for an air-core coil?

.99

Hi .99,

thanks for the confirmation and information.

Yes, the coil specs I gave you are for an air-core coil.

I'm been asking you all the questions about coil inductance and so on because I have a 6 pond spool of no. 10 AWG which I think has about 70 feet of rated 200c magnet wire.

I measured its DC resistance with my quality meter and it is .15 Ohm so we have next to no resistance here. I would like to wind it to maximize effects but don't want to waste the wire by not clearly understanding what we have been talking about. So let me pass this by you and let me know if you believe it to be the best way to wind this amazing piece of wire.

From what I now understand, one wants to get the highest inductance value when winding a coil. However to achieve this and obtain best results one needs to consider two things:

No.1, use the Brooks geometry, which is the coils opening diameter is to be twice the size of the finished coil thickness.

No.2, make as many turns as possible but keeping the Brooks geometry

so if these are going to give the best results then here is what I propose.

Make a single layer coil with a core opening diameter to be twice the size of the thickness of the wire. We would then have the most turns as possible and also respect the Brooks geometry.

No. 10 AWG wire is = .1019" (2.59mm) X 2 = .2038 (5.18mm) diameter center

So maybe I can just use a .25" wood stick or steel rod as guide to wind this thick wire.

What do you think of this? do you think it would give the best result before I turn all this wire into a giant curly pot washer

Thanks for your time.

Luc

[poynt99]

Brooks Geometry and how to make one

Hi Luc.

Your proposed coil construction is not quite correct I think if you want to keep to the Brooks geometry.

You want the coil windings to be "square", so this already implies a multi-layer coil. Look at the picture below:



So in summary, you want the windings to end up in a multi-layer square configuration as shown, and the coil former hole diameter is twice that of one side of your square coil dimension, i.e the "A" or "B" dimension.

Does that make sense?

.99

[gotoluc]

Hi .99,

yes that makes sense but won't give us the highest inductance as more wire length will be needed as the layers are added and the less turns we will end up with.

My thinking was, (see attached) if we look at my very thick wire as the coils thickness then at least we are keeping one of the Brooks ideal coil configurations.

This is why I was asking if there is a simulation program available that we could test each configurations to compare the results.

Is this something you can test in SPICE?

Thanks

Luc

[poynt99]

Hi .99,

yes that makes sense but won't give us the highest inductance as more wire length will be needed as the layers are added and the less turns we will end up with.

That doesn't make sense to me. Am I missing something?

My thinking was, (see attached) if we look at my very thick wire as the coils thickness then at least we are keeping one of the Brooks ideal coil configurations.

What that looks like to me is a one-turn coil. That's not what we want to build.

This is why I was asking if there is a simulation program available that we could test each configurations to compare the results.

Is this something you can test in SPICE?

Thanks

Luc

The only simulation programs I am aware of that can see magnetic fields is Finite Element type programs, and they aren't that easy to use typically.

FEMM is one that is not too bad, and it is free. I believe it can be used with coils, but I have never spent the time to figure out how to. I've just used it for permanent magnet simulations.

.99

[gotoluc]

That doesn't make sense to me. Am I missing something?

Humm ... makes sense to me Okay, lets try this. As we start a layer over the first layer the diameter of the coil is now larger because we have increased it with the wire thikness of the first layer, so we will need more wire to make the second layer over the first and again the same thing will happen every extra layer that is added. This is not a big deal when we use thin wire but when we use 10 AWG it will make a big difference.

FEMM is one that is not too bad, and it is free. I believe it can be used with coils, but I have never spent the time to figure out how to. I've just used it for permanent magnet simulations.

.99

I'll have a look at it. Thanks

Luc

[poynt99]

OK Luc,

I will give you a hypothetical coil specification to build, and you tell me if it meets with the Brooks coil geometry.

Wire diameter = 1mm
coil former hole = 20mm
coil former width = 10mm
number of turns per layer = 10
number of layers = 10

Resulting coil dimensions with reference to diagram as before:

A = B = 10mm (1mm x 10 layers and 10 turns respectively)
r = 15mm
total coil/former diameter (not shown) = 40mm

So your number of layers must equal your number of turns per layer to keep the shape square! Does this make sense now?

.99