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Author Topic: Self running coil?  (Read 302312 times)

void109

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Re: Self running coil?
« Reply #525 on: April 08, 2010, 10:03:17 PM »
I want to try to state this again, to be sure I understand.

If we have our Finemet coil - and we pulse it with x Current, such that the core is saturated (no more room for flux!), we can then, while saturated, lower it toward the magnets 'sweet spot', where by the inductance will increase 300%, its capacity for storing flux by 300%, and we can then store more energy in the magnetic flux?

If that sounds like an accurate description of what this implies - anyone fancy an idea as to where this extra flux gets stored?  Does the presence of this sweet spot perhaps increase the permeability even further (300%)?

I'm sorry if this is derailing the thread, seemed like it may be relevant.  As a side note - instead of fiddling with H-Bridge circuits which arent working out quite how I'd like, I'm just going to run to a second hand store and get a big audio hi-fi amp to amplify the signal from my generators.  No sense in banging my head on those concepts when I'm just trying to research various phenomena.  Any reason that's a bad notion?

-void

gyulasun

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Re: Self running coil?
« Reply #526 on: April 08, 2010, 10:47:27 PM »
I want to try to state this again, to be sure I understand.

If we have our Finemet coil - and we pulse it with x Current, such that the core is saturated (no more room for flux!), we can then, while saturated, lower it toward the magnets 'sweet spot', where by the inductance will increase 300%, its capacity for storing flux by 300%, and we can then store more energy in the magnetic flux?

If that sounds like an accurate description of what this implies - anyone fancy an idea as to where this extra flux gets stored?  Does the presence of this sweet spot perhaps increase the permeability even further (300%)?

I'm sorry if this is derailing the thread, seemed like it may be relevant.  As a side note - instead of fiddling with H-Bridge circuits which arent working out quite how I'd like, I'm just going to run to a second hand store and get a big audio hi-fi amp to amplify the signal from my generators.  No sense in banging my head on those concepts when I'm just trying to research various phenomena.  Any reason that's a bad notion?

-void

@void

If you go through again what was written then you find out that nobody meant or implied what you deduced above,  sorry.

I did not write that first you saturate the Finemet core with current then you can increase its inductance by a strong permanent magnet placed near to it in the way you showed in the video.  IF you have read such, please point me to that mail.

Member Gravityblock wrote this, I qouted in bold what is important:

The Finemet manufactured from Metglas is a (FT-3AH) and is a square loop core, http://www.scribd.com/doc/28763938/FineMet-Materials

I suspect the inductance is increasing until the core is right below the "knee" of the B-H Curve. Any further increase in saturation from this point, then the core's inductance will decrease.

This means if the magnet is placed at a distance where the inductance is the highest in this core material, then it will take very little input energy to fully saturate the core.
....

So I do not think he meant the opposite sequence as you got it.
First step is to align the magnet wrt the core to cause an inductance increase as much as possible, just to the edge beyond which inductance value collapses down.
Second step is to apply a current which can be a small one to help bring the core into the saturation state (as if you had moved the magnet say half a millimeter closer, to cause the inductance collapse.

The original ORBO concept Luc referred to (when he described his idea for applying this inductance increase you showed to an ORBO-like setup) is that a magnet approaches a toroidal core perpendiculary, saturates that part of the core, then current is introduced into the coil on the core to help deepen the saturation so that the magnet could easily escape from the attraction. 

Hope this helps.

Gyula

gotoluc

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Re: Self running coil?
« Reply #527 on: April 08, 2010, 11:00:16 PM »
Hi void,

please don't think this is derailing the thread as this could bring much more light to the topic.  I'm very interested and I'm sure others are also.

Using an Audio amp is a good idea for frequencies below 20Khz

I can't help you with your question as I'm not sure it was explained like that. I think Gyula tried to make it clearer. One way or the other it's best to test and see the results to learn.

Looking forward to a test video ;)

Thanks for sharing

Luc

gyulasun

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Re: Self running coil?
« Reply #528 on: April 08, 2010, 11:21:09 PM »
...
User Peterae sent me a Toroid a month ago: http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=3057010 
I was saving it for when I find the ideal winding I want. However, last night I decided to wind it using 1 meter of 30AWG 25mm wire on that core which gave 24 turns. The resulting inductance is 9mH which I found kind of high so I wound the same 1 meter of 30AWG 25mm wire on the ferrite toroid core that I have been using in all my tests and it gives 30 turns. Its inductance is 1.22mH.

I'm confused as to why there is such a big difference. Is it the little bit of extra mass? Peterae Toroid TX36/23/15-3E5: OD 36.30mm, ID 22.55mm, height 15.5mm, width 6.8mm compared to my Regular Toroid I have: OD 34.45mm, ID 20.0mm, height 11.95mm, width 6.85mm

If someone can help explain the difference that would be helpful and appreciated.

Thanks

Luc

Hi Luc,

The so called AL value for the Ferroxcube core is 11400nH/N2 (taken from the Farnell link). If you wound 24 turns on it then the formula for L is L=N2*AL=24*24*11.4=6.566mH
You measured 9mH instead, this difference can only be explained by a high manufacturing tolerance. 
On you other 'usual'  core you got 1.22mH for the 30 turns from the same length of wire. If I recall the AL value I calculated for your core is AL=1298.6nH/N2   This gives 30*30*1.2986=1.168mH, very close to your measured 1.22mH.

The big difference comes from the big AL value differences. Putting it otherwise: the Ferroxcube core has a much higher permeability than the other core.  (7730 vs 1196)

rgds, Gyula

void109

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Re: Self running coil?
« Reply #529 on: April 09, 2010, 12:20:47 AM »
Oh I wasnt saying anyone proposed that example, that was just a thought experiment on my part - given assertions that were made, which were:

1 - Higher inductance means it takes more current to saturate the core (?)

2 - Saturation means that the core material cannot contain any further flux (?)

3 - The inductance of the coil increases in a certain position and arrangement relative to the permanent magnet (?)

4 - If the saturation increases - that implies that the coil now has increased capacity to contain further flux (?)

Those are my assumptions based on my current understanding.

So what I said before was a thought experiment based on the above postulates - if any of those assertions are wrong - please tell me :)   And number 3 is just from my own experiment, the first two are factoids I've gleaned from folks here more knowledgeable than myself like you fine gentlemen.  The thought experiment just outlined my confusion as to the *how* the inductance can rise given its proximity to the magnet.  I appreciate the feedback.

gotoluc

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Re: Self running coil?
« Reply #530 on: April 09, 2010, 05:23:05 AM »
Hi Luc,

The so called AL value for the Ferroxcube core is 11400nH/N2 (taken from the Farnell link). If you wound 24 turns on it then the formula for L is L=N2*AL=24*24*11.4=6.566mH
You measured 9mH instead, this difference can only be explained by a high manufacturing tolerance. 
On you other 'usual'  core you got 1.22mH for the 30 turns from the same length of wire. If I recall the AL value I calculated for your core is AL=1298.6nH/N2   This gives 30*30*1.2986=1.168mH, very close to your measured 1.22mH.

The big difference comes from the big AL value differences. Putting it otherwise: the Ferroxcube core has a much higher permeability than the other core.  (7730 vs 1196)

rgds, Gyula

Thanks once again Gyula for your time in explaining this!  much appreciated :)

I have more questions regarding the BH curves and permeability and was wondering if we could just talk on Skype, it would be much faster than writing and save time. Are you set up and able to do this?

Thanks

Luc

void109

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Re: Self running coil?
« Reply #531 on: April 09, 2010, 05:52:45 AM »
I'm wondering if the magnets effect on the toroid may be interfering with whatever method the LCR meter uses to determine the inductance.  I've paired this toroid with several capacitors, and using the inductance it appears to have while positioned on the magnet, and I have not yet been able to get a resonant sine wave out of it.  So I'm wondering if the inductance reading isn't just incorrect.

gotoluc

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Re: Self running coil?
« Reply #532 on: April 09, 2010, 06:36:30 AM »
I'm wondering if the magnets effect on the toroid may be interfering with whatever method the LCR meter uses to determine the inductance.  I've paired this toroid with several capacitors, and using the inductance it appears to have while positioned on the magnet, and I have not yet been able to get a resonant sine wave out of it.  So I'm wondering if the inductance reading isn't just incorrect.

Hi void,

at what frequency are you trying to get resonance?

Luc

gyulasun

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Re: Self running coil?
« Reply #533 on: April 09, 2010, 11:24:19 PM »
...
 Yes it is a shaded pole motor inductor that I use as pulse coil because it's easy to adjust the exact inductance needed by just sliding in or out a long ferrite rod that I made by super gluing 2 AM radio loop stick antenna ferrite rods together. With it I can vary the inductance from 35mH to 350mH. Anyways, it's DC resistance is 67 Ohms. I know many will say that it's a waste of energy but I tried it with my single wound 6.9 Ohm toroid coil and I see no difference. Perhaps because at resonance the coils resistance is not seen? Let me know what you think of this.   

Yes I tried the pulse coil with the toroid as stated above but found no gain.

I don't know much about coil Q so I don't know what to answer ???


Hi Luc,

It is interesting you did not find any advantage in using a toroidal core+coil instead of the shaded pole motor coil.  I wonder if the two coils had the same inductance then? (it would mean the oscillator had run nearly on the same frequency with the two different kind of coils.

Yes, the motor coil's 67 Ohm DC resistance is very high, unusual to use it in an oscillator where generally everything is done to reduce losses in the resonant LC circuit that also determines the oscillating frequency  :)

Well, normally the higher a coil Q, the less loss it has, this means the less input energy is needed for maintaining oscillation. (coil loss=DC resistance + core hysteresis and eddy current losses)  At resonance the coil's DC resistance 'disappears' indeed, a resonant impedance appears across the coil instead, this can be from several tens to a few hundreds of kOhm range at your frequencies involved, just because the Q 'magnifies' the resonant impedance hence voltage.
Maybe it would be wise to check again at one frequency in your oscillator, what advantage if any a high Q coil has versus the low Q motor coil. This would involve picking a frequency where you can insure the same inductance for both coils, especially if you have already a ready toroidal coil in the 100-240mH range to which you can easily match the motor coil's inductance with the ferrite rods.
In a high Q LC circuit the resonant AC voltage can be much higher than in a low Q one because of the less losses involved. Normally this is beneficial for an oscillator but in your MOSFET circuit the peak to peak voltage should not be let to be higher than about 40Vpp because the allowable maximum gate-source voltage must be +/-20V (FET type dependent though but valid for most).
The higher resonant AC voltage means that the LC tank can store higher reactive peak power  i.e. the circuit would need even less input current to make up for the less loss.  Could you recall what the gate-source voltage was when you used a toroidal coil for the pulse coil?
IF you found no significant difference, maybe the first step would be to check what the Q of that toroidal core actually is. Whenever you have time you could measure the Q of these coils as I outlined in an earlier post:
http://www.overunity.com/index.php?topic=8892.510
This way you can also gain some further insite what the Q means for coils.

rgds,  Gyula

PS 1)  Thank you for asking on the Skype, I do not use it (not yet installed). By the way I am not an expert on the B-H curves... for instance I wish I knew the real explanation why the L increases on a toroidal coil when you parallel facing its core with a big magnet...

2) I have seen the data sheets of your newer FETs, perhaps IRLML2502 seems the most promising with its low gate threshold voltage and gate charge needs.

gyulasun

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Re: Self running coil?
« Reply #534 on: April 09, 2010, 11:46:01 PM »
Oh I wasnt saying anyone proposed that example, that was just a thought experiment on my part - given assertions that were made, which were:

1 - Higher inductance means it takes more current to saturate the core (?)

2 - Saturation means that the core material cannot contain any further flux (?)

3 - The inductance of the coil increases in a certain position and arrangement relative to the permanent magnet (?)

4 - If the saturation increases - that implies that the coil now has increased capacity to contain further flux (?)

Those are my assumptions based on my current understanding.

So what I said before was a thought experiment based on the above postulates - if any of those assertions are wrong - please tell me :)   And number 3 is just from my own experiment, the first two are factoids I've gleaned from folks here more knowledgeable than myself like you fine gentlemen.  The thought experiment just outlined my confusion as to the *how* the inductance can rise given its proximity to the magnet.  I appreciate the feedback.

1) All I can say is that it is a complex problem, depends on several factors.   (What I wrote to Luc on it was in connection of his ORBO question, see it in my earlier posts.)

2) Here is explanation from this link http://en.wikipedia.org/wiki/Saturation_%28magnetic%29 :
"Ferromagnetic materials like iron that show saturation are composed of microscopic regions called magnetic domains that act like tiny permanent magnets. Before an external magnetic field is applied to the material, the domains are oriented in random directions. Their tiny magnetic fields point in random directions and cancel each other out, so the material has no overall net magnetic field. When an external magnetizing field H is applied to the material, it penetrates the material and aligns the domains, causing their tiny magnetic fields to turn and align parallel to the external field, adding together to create a large magnetic field which extends out from the material. This is called magnetization. The stronger the external magnetic field, the more the domains align. Saturation occurs when practically all the domains are lined up, so further increases in applied field can't cause further alignment of the domains. This is a simplified account; a more complete explanation can be found in Ferromagnetism."

3) You have made nice experiments on your question, carry on and learn.

4) See the link at 2) above.

chadj

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Re: Self running coil?
« Reply #535 on: April 10, 2010, 01:19:42 AM »
Well GB,

here is my  about the Finemet cores. Maybe no one got some because they are next to impossible to buy.

Metglas says their distributor is Elna Magnetics. I called Elna Magnetics and they have no stock, never had. You have to fax them a detailed purchase request and then they will look into it. So I called Metglas and the one person operating this business is away till tomorrow :-\

This does not sound like an available item to me. Nothing else can be found!

User Peterae sent me a Toroid a month ago: http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=3057010 
I was saving it for when I find the ideal winding I want. However, last night I decided to wind it using 1 meter of 30AWG 25mm wire on that core which gave 24 turns. The resulting inductance is 9mH which I found kind of high so I wound the same 1 meter of 30AWG 25mm wire on the ferrite toroid core that I have been using in all my tests and it gives 30 turns. Its inductance is 1.22mH.

I'm confused as to why there is such a big difference. Is it the little bit of extra mass? Peterae Toroid TX36/23/15-3E5: OD 36.30mm, ID 22.55mm, height 15.5mm, width 6.8mm compared to my Regular Toroid I have: OD 34.45mm, ID 20.0mm, height 11.95mm, width 6.85mm

If someone can help explain the difference that would be helpful and appreciated.

Luc

Luc,

I think someone else already explained that the higher permeability is why you are getting more inductance. The material permeability has nothing to do with weight. It relates to how much the magnetic domains rotate when you apply an H-field (magnetizing force) with the coil. Some lighter materials have greater permeability. When the coil applies a magnetic field the core responds by creating a parallel B-field (magnetic field) much stronger then the H-field because it is paramagnetic.

The ratio of B to H gives the permeability. When the core begins to saturate its permeability will decrease until it is the same as air. Materials with hysteresis get magnetized when they approach saturation. When this happens you get (conventionally) energy loss because it takes energy to magnetize and demagnetize the core. You would typically only want to drive your coil to saturation for current regulation or amplification (mag-amp).

Ferrites have very little hysteresis but cores made of materials like metglas or orthonol are designed to have lots of it. These are called strip would cores because they are made from a long metal strip. It is often hard for amateurs to get these because suppliers don't want to deal with them but you can find a few cheap ones at this surplus site:

http://www.surplussales.com/Inductors/FerToro/FerToro-3.html

I can't really say if you would want to experiment with a strip would core because the ferrite is supposed to be more efficient. Maybe someone can buy a bunch of strip wound cores from a supplier and sell them on e-bay? (great biz-op!)

I hope this helps,
Chad.






darik

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Re: Self running coil?
« Reply #536 on: April 17, 2010, 03:52:37 PM »
Hi Luc,

You may want to check the lecture 22 of Professor Lewin.
http://www.youtube.com/watch?v=ddU6HBFlvEk&feature=PlayList&p=A19E8985A925326B&playnext_from=PL&index=7

I found it very informative and helpful.


mscoffman

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Re: Self running coil?
« Reply #537 on: April 29, 2010, 04:45:57 PM »
Because this may be relevant to experimenters here:

According to Paul Lawrance via his blogsite; http://globalfreeenergy.info/

“A tip is that all of my cores show a highly unusual property that is *NOT*
typical. The inductance of a normal core will decrease when placed near
a magnet. The Metglas MAGAMP cores show the opposite, where the
inductance actually increases when placed near a magnet. Of course,
if you place a strong magnet too close, then the inductance shoots
down even in the Metglas MAGAMP cores.

Some quick measurement taken a few minutes ago using the DM4070 LCR
meter on my Metglas MAGAMP cores shows an increase of 1.4 to 1.5 times
typically.”

My Disclaimer:

Like him, I am concerned about the possibly that the measurement
procedure used by a particular instrument might present a "less than
global” picture about what is going on in the inductor. He goes on to
claim that this behavior in toroids as shown by his equations equates
to the basis of free energy.

:S:MarkSCoffman

Magluvin

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Re: Self running coil?
« Reply #538 on: November 08, 2011, 07:18:09 AM »
Been reading a pdf(below) that show these oppositely wound coils. I shows some different ways of connecting them.

The pdf is a bit cryptic. But the ideas come through after reading a few times.

Luc, I see the circuit you used(its been a while) back then.
No diode. Is there one in the fet for charging the cap?

Just finished winding a toroid your way, but not 5 layers of turns. Trying things.

Mags

Magluvin

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Re: Self running coil?
« Reply #539 on: November 08, 2011, 07:25:56 AM »
Sorry, the file is word(forgot) and is too large to upload. Ill see if I can convert to pdf or zip it tomorrow.

Mags