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OverUnity Research > Electrical / Electronic Devices > Tariel Kapanadze's Devices (Moderators: verpies, Apecore) > Grenade coil type systems
2024-11-26, 12:23:06
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Author Topic: Grenade coil type systems  (Read 39748 times)
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Re: Grenade coil type systems « Reply #200 on: 2023-10-07, 16:05:31 »
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Soldering aloy easy just put some mineral oil where your soldering scratch it so the oil can
get into the none oxidized scratch then solder it with ordinary solder, use to work on pistons
in an old bike when i was a kid !
Sil
   
img  Itsu
Re: Grenade coil type systems « Reply #201 on: 2023-10-07, 16:13:23 »

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Quote from: verpies on 2023-10-07, 13:02:28
Gulp  :o

So what are the dimensions and material of these soft cores and these magnets ?
Do you have any way to measure the magnetic flux density in the gap where the Al tube is ?


Good question about the soft core material, i don't know (anymore) as i bought them some 10 years ago.

Their dimensions are 5cm OD, 2.5cm ID and 3cm thick.

The magnets i salvaged from 2 magnetrons and are rather strong measuring 5.7cm OD, 2.5cm ID and 1.3cm thick.

The alu piece has an OD of 4.2cm and 3cm wide (3mm thick alu).

I only have a Hall sensor probe, not calibrated, but thinking of buying a Gauss meter like the WT10A (static magnetic fields only), so i will see what i can do.


Itsu
   
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Re: Grenade coil type systems « Reply #202 on: 2023-10-07, 17:11:57 »
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Quote from: AlienGrey on 2023-10-07, 16:05:31
Soldering aloy easy just put some mineral oil where your soldering scratch it so the oil can
get into the none oxidized scratch then solder it with ordinary solder, use to work on pistons
in an old bike when i was a kid !
Sil

I tried that without much success. It didn't work very well with foil in particular due to the fragile nature of it.

Does it have to be mineral oil, or any oil so as to prevent immediate oxidization after scratching the oxide layer off?
   
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Re: Grenade coil type systems « Reply #203 on: 2023-10-07, 18:20:54 »
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The oil has to be thin and not solidify when it's hot some thing like 3 on 1 you cant let the air get at it or it's game over, experiment, practice makes perfect.

Sil
   
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Re: Grenade coil type systems « Reply #204 on: 2023-10-07, 19:15:26 »
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Quote from: Itsu on 2023-10-07, 16:13:23

Good question about the soft core material, i don't know (anymore) as i bought them some 10 years ago.

Their dimensions are 5cm OD, 2.5cm ID and 3cm thick.

...


Hi Itsu,

At least the permeability of the cores could be known by using a free software the Mini Ring Core Calculator (you may know about it):   https://mini-ring-core-calculator.software.informer.com/

It has a built-in calculator in the Tools menu where it asks for the OD, ID and the thickness and asks for a measured inductance for a choosable number of turns on it.

I have this software installed and if you wish, just wind say 10 turns on a core and measure with an L meter its inductance perhaps at the lowest frequency the L meter is able to measure.  Then we can get the permeability from the calculator, together with the AL factor too. 

Gyula
   
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Re: Grenade coil type systems « Reply #205 on: 2023-10-07, 20:00:39 »

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Thanks Gyula,

i did not have that calculator tool, but i downloaded it and got this result of my soft core:



Itsu
   
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Re: Grenade coil type systems « Reply #206 on: 2023-10-07, 20:39:13 »
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Okay, thanks.  Here is one manufacturer, Fair-Rite with their 43 type material having a permeability of 800, very close to your core: https://fair-rite.com/43-material-data-sheet/
Here is another 43 material specs (u=850):  https://www.cwsbytemark.com/CatalogSheets/Ferrite_datasheet_oct06/FR_MATL.pdf

I think your core is made of this 43 material... 

Gyula
   
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Re: Grenade coil type systems « Reply #207 on: 2023-10-07, 21:18:13 »
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TDK (now Epcos I think) also has their K10 material with approx permeability of 700 but their OD=50mm  ID=30mm, h=20mm: https://www.farnell.com/datasheets/3974271.pdf 
The core you bought some 10 years ago may have become obsolote by now of course.

Surely there are other manufacturers with such toroid cores with material permeabilities of 700 - 800.

Gyula
   
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Re: Grenade coil type systems « Reply #208 on: 2023-10-07, 21:18:49 »

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Quote from: Itsu on 2023-10-07, 16:13:23
Good question about the soft core material, i don't know (anymore) as i bought them some 10 years ago.
It was nice of Gyula to help you with this software.  Maybe it really is the type 43 material.

There is another experiment that can be easily made that will tell you a lot about a ferrite:
Make a 1:1 transformer out if this ferrite and make the primary and secondary out of tight 1-turn each *.
Keep them far apart (diametrically opposite on the core) to avoid any capacitive coupling.  Then, make a S21 measurement with a VNA and you will obtain the ferrite's fingerprint. (its frequency characteristic).

For example this supplier shows this plot for the type 43 material:



Callibrate without the ferrite, with the same two loops next to each other like this.

* It's best to make the 1-turn windings out of the coax cables that connect the 1:1 transformer to the VNA ( tightly soldered around the core in the manner of the H-probes ).
« Last Edit: 2023-10-09, 11:24:49 by verpies »
   
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Re: Grenade coil type systems « Reply #209 on: 2023-10-07, 22:26:34 »

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Quote from: Itsu on 2023-10-07, 16:13:23
I only have a Hall sensor probe, not calibrated, but thinking of buying a Gauss meter like the WT10A (static magnetic fields only), so i will see what i can do.
I have that meter and I have to warn you that it came uncalibrated.

Meanwhile, perhaps you could measure how many ampturns are needed to cancel the axial magnetic flux in that gap. 
You can do it by winding a low quality temporary coil on that soft ferrite sausage half, which is not adjacent to the magnets, and see how much direct current is needed to rotate a small compass placed in this gap by 90°.

Similar (but not exactly) to this:
   
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Re: Grenade coil type systems « Reply #210 on: 2023-10-08, 16:12:16 »

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Well, with the 4 ring magnets attached to the soft cores, the compass needle is doing noting with 11A going through a 24 turn coil.
Even with a single ring magnet there is ample movement, so i had to back off this single ring magnet 5cm away from the soft cores to create this 90° movement at 10A through the coil.

11A is the max current i can push at the moment.



Itsu
« Last Edit: 2023-10-18, 15:36:22 by Itsu »
   
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Re: Grenade coil type systems « Reply #211 on: 2023-10-08, 17:17:20 »

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Quote from: Itsu on 2023-10-08, 16:12:16
Even with a single ring magnet there is ample movement, so i had to back off this single ring magnet 5cm away from the soft cores to create this 90° movement at 10A through the coil.
Yeah the equivalent surface current in magnets is in the kA range, but I was estimating that the long magnetic path will attenuate the flux density in the gap.
Since it is the ampturns that oppose the magnet (not Amps alone), my next question is:  What is the thinnest wire that you have that can withstand 10A without burning its insulation?  Warm is fine...
   
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Re: Grenade coil type systems « Reply #212 on: 2023-10-08, 17:50:52 »

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I tested a piece of 1mm magnet wire, it got warm after 2 minutes
   
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Re: Grenade coil type systems « Reply #213 on: 2023-10-08, 18:33:33 »

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Quote from: Itsu on 2023-10-08, 17:50:52
I tested a piece of 1mm magnet wire, it got warm after 2 minutes
How much you've got ?
Enough to make several hundred ugly turns with your drill or lathe ?
   
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Re: Grenade coil type systems « Reply #214 on: 2023-10-08, 20:30:10 »

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I will have to see what i can do.

Itsu
   
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Re: Grenade coil type systems « Reply #215 on: 2023-10-08, 20:58:13 »

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Quote from: verpies on 2023-10-07, 21:18:49
It was nice of Guyla to help you with this software.  Maybe it really is the type 43 material.

There is another experiment that can be easily made that will tell you a lot about a ferrite:
Make a 1:1 transformer out if this ferrite and make the primary and secondary out of tight 1-turn each *.
Keep them far apart (diametrically opposite on the core) to avoid any capacitive coupling.  Then, make a S21 measurement with a VNA and you will obtain the ferrite's fingerprint. (its frequency characteristic).

For example this supplier shows this plot for the type 43 material:



Callibrate without the ferrite, with the same two loops next to each other like this.

* It's best to make the 1-turn windings out of the coax cables that connect the 1:1 transformer to the VNA ( tightly soldered around the core in the manner of the H-probes ).


Concerning this post, i see what you mean, but it's not easily done, like i have to solder / desolder those 1 turns coaxes several times like to test around the core, then calibrate, then again around the core to measure.

Instead, i tried it with simple magnet wire loops, and the results do kind of match the graph of the manufacturer (S21 (Z) shunt):



So i guess it's indeed type 43 material.


Itsu
« Last Edit: 2023-10-18, 15:38:37 by Itsu »
   
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Re: Grenade coil type systems « Reply #216 on: 2023-10-08, 21:32:04 »

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Quote from: Itsu on 2023-10-08, 20:58:13
... I have to solder / desolder those 1 turns coaxes several times like to test around the core, then calibrate, then again around the core to measure.
Yes, but without it the results will not be maximally accurate.

Quote from: Itsu on 2023-10-08, 20:58:13
So i guess it's indeed type 43 material.
Perhaps not.
Your ferrite transformer appears to transfer signals up to 100MHz without distortions.  Notice that your S21 plot is quite flat up to 100MHz and squiggles begin only at ~140MHz. So if you make a 1:1 Balun from it, then it will work well up to 100MHz for sure.

Take a look at the "1:1 Balun (Choke)" column in the table published by this supplier :



You can notice that according to it, the type 43 material would not be able to transfer 100MHz signals and there is only one ferrite material type on that list, which is suitable for 1:1 Baluns up to 100MHz.
That, combined with the 713 relative permeability at 100kHz, suggests that it is a different material, yet.
« Last Edit: 2023-10-08, 23:08:43 by verpies »
   
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Re: Grenade coil type systems « Reply #217 on: 2023-10-09, 09:58:20 »

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Ok, so based on my plot it more points to type 61 material although the relative permeability of 125 contradicts that.
It's a pity that that supplier does not show a graph of the type 61 material.

Anyway, i will try again with some coax loops like an H field probe (does those include the outer shield cuts, i can't really see on your loops picture)?

Itsu
   
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Re: Grenade coil type systems « Reply #218 on: 2023-10-09, 11:12:55 »

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Quote from: Itsu on 2023-10-09, 09:58:20
It's a pity that that supplier does not show a graph of the type 61 material.
...but Gyula's source does:
https://fair-rite.com/61-material-data-sheet/

Quote from: Itsu on 2023-10-09, 09:58:20
...does those include the outer shield cuts, i can't really see on your loops picture ?
Yes.  You cannot see them because I epoxied the shield-gap. If you want to quickly take the cable loop off/on the core, you can cut the center conductor in the center of the shield-gap, too.  Just make the shield-gap wide enough for your smallest soldering tip to fit in it and allow you to make a quick butt joint of the center conductor.   Lap joints are stronger but not recommended because they can change the length of the loop after calibration.
   
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Re: Grenade coil type systems « Reply #219 on: 2023-10-09, 20:59:11 »
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Hi Verpies,
Very nice to see Itsu and you are in good understanding about the effort.
Could you explain in a short semy detailed summary the last discoveries/ standings? As in which you and Itsu are engaging?

Thanks in advance

I prefer to do kind of regular short reviews on the follow ups that where done.
This helps us to understand and stay focused
   
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Re: Grenade coil type systems « Reply #220 on: 2023-10-09, 21:16:22 »

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Quote from: Apecore on 2023-10-09, 20:59:11
Could you explain in a short semy detailed summary the last discoveries/ standings? As in which you and Itsu are engaging?
There are two experiments going on.
One is to confirm/refute that a magnetic disturbance of a short pulse is confined inside a shielded, grounded and terminated (or shorted) coaxial cable.  So far it doesn't look like it ...but there are still some open places from which the pulse can leak out. 
If coils wound with ungapped coaxial cable are possible then it would be news to me and a pathway to generate clean pulsed magnetic fields without the ITC messing it up.

The second experiment is centered around characterizing Itsu's unknown ferrite material and determining its frequency response as well as determining the magnetic flux density in the gap between two ferrite sausages, generated by adjacent permanent magnets or alternatively, the H field needed to cancel their flux in that gap.
   
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Re: Grenade coil type systems « Reply #221 on: 2023-10-10, 18:49:16 »
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Quote from: verpies on 2023-10-09, 21:16:22

The second experiment is centered around characterizing Itsu's unknown ferrite material and determining its frequency response as well as determining the magnetic flux density in the gap between two ferrite sausages, generated by adjacent permanent magnets or alternatively, the H field needed to cancel their flux in that gap.

You need its parameter for calculation purpose?
   
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Re: Grenade coil type systems « Reply #222 on: 2023-10-10, 18:56:36 »

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Quote from: Apecore on 2023-10-10, 18:49:16
You need its parameter for calculation purpose?
Yes or he will have to hunt for ±10Hz resonance all over the spectrum with unknown amplitudes.
   
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Re: Grenade coil type systems « Reply #223 on: 2023-10-10, 19:28:32 »
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Quote from: verpies on 2023-10-10, 18:56:36
Yes or he will have to hunt for ±10Hz resonance all over the spectrum with unknown amplitudes.

Would be nice Itsu succeeds in the test setup and solid testprotocol with reliable outcome.
This means if obligation 1 is realistic you probably like to use a different ferrite/ magnet setup.
   
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Re: Grenade coil type systems « Reply #224 on: 2023-10-11, 10:09:47 »

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Things are slow here, sorry about that, bench time seems scarce lately, but i am still working on those above-mentioned items.

Itsu
   
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