Type 43 material for common-mode choke...

[bitrex]

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

<https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.>

but I think that\'s a misprint, looks more like 15MHz:

<https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg>

The data-sheet is here:

<https://www.fair-rite.com/43-material-data-sheet/>

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

 

[legg]

On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <user@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

That\'s a 5943000201 in the Fair-Rite catalog. Al = 375nH/n^0.5.

You\'d only need 16 turns x2 to get a 2x100uH common mode choke.

It\'s the right material for the application.

RL

 

[bitrex]

On 9/24/2020 11:17 PM, legg wrote:

On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <user@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

That\'s a 5943000201 in the Fair-Rite catalog. Al = 375nH/n^0.5.

You\'d only need 16 turns x2 to get a 2x100uH common mode choke.

It\'s the right material for the application.

RL

Yes you\'re right, 16, thank you. Nice

 

[Jeroen Belleman]

legg wrote:

On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <user@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

That\'s a 5943000201 in the Fair-Rite catalog. Al = 375nH/n^0.5.

375nH/n^2

You\'d only need 16 turns x2 to get a 2x100uH common mode choke.

It\'s the right material for the application.

Yes.

Jeroen Belleman

 

[boB]

On Fri, 25 Sep 2020 09:31:40 +0200, Jeroen Belleman
<jeroen@nospam.please> wrote:

legg wrote:
On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <user@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

That\'s a 5943000201 in the Fair-Rite catalog. Al = 375nH/n^0.5.

375nH/n^2


You\'d only need 16 turns x2 to get a 2x100uH common mode choke.

It\'s the right material for the application.

Yes.

Jeroen Belleman

Too many turns can eventually give diminishing returns due to too much
intra-winding capacitance.

 

[Bill Sloman]

On Saturday, September 26, 2020 at 3:20:43 PM UTC+10, boB wrote:

On Fri, 25 Sep 2020 09:31:40 +0200, Jeroen Belleman
jer...@nospam.please> wrote:

legg wrote:
On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <us...@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

That\'s a 5943000201 in the Fair-Rite catalog. Al = 375nH/n^0.5.

375nH/n^2


You\'d only need 16 turns x2 to get a 2x100uH common mode choke.

It\'s the right material for the application.

Yes.

Too many turns can eventually give diminishing returns due to too much
intra-winding capacitance.

You can work that out. Sixteen turns on a toroid sounds like a single layer winding, where the parallel capacitance tend to be around 1pF, which would make the coil parallel resonant at about 8MHz (very roughly).

As soon as you start stacking up layers of windings, life gets more difficult and you have to starting thinking about partitioning the winding into successive multilayer chunks, where there isn\'t a lot of voltage difference within any one chunk.

--
Bill Sloman, Sydney

 

[Piglet]

On 26/09/2020 06:36, Bill Sloman wrote:

On Saturday, September 26, 2020 at 3:20:43 PM UTC+10, boB wrote:
On Fri, 25 Sep 2020 09:31:40 +0200, Jeroen Belleman
jer...@nospam.please> wrote:

legg wrote:
On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <us...@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

That\'s a 5943000201 in the Fair-Rite catalog. Al = 375nH/n^0.5.

375nH/n^2


You\'d only need 16 turns x2 to get a 2x100uH common mode choke.

It\'s the right material for the application.

Yes.

Too many turns can eventually give diminishing returns due to too much
intra-winding capacitance.

You can work that out. Sixteen turns on a toroid sounds like a single layer winding, where the parallel capacitance tend to be around 1pF, which would make the coil parallel resonant at about 8MHz (very roughly).

Very roughly indeed, an octave out - I make 1pF 100uH resonant at 16MHz

As soon as you start stacking up layers of windings, life gets more difficult and you have to starting thinking about partitioning the winding into successive multilayer chunks, where there isn\'t a lot of voltage difference within any one chunk.

piglet

 

[Piotr Wyderski]

Piglet wrote:

> Very roughly indeed, an octave out - I make 1pF 100uH resonant at 16MHz

I would say an octave is good enough for a SWAG. Even a decade would
pass in most of the cases.

Best regards, Piotr

 

[Piglet]

On 26/09/2020 09:12, Piotr Wyderski wrote:

Piglet wrote:

Very roughly indeed, an octave out - I make 1pF 100uH resonant at 16MHz

I would say an octave is good enough for a SWAG. Even a decade would
pass in most of the cases.

Best regards, Piotr

You are right when some information is missing but in this case all the
data was available to calculate better.

piglet

 

[Bill Sloman]

On Saturday, September 26, 2020 at 6:00:29 PM UTC+10, piglet wrote:

On 26/09/2020 06:36, Bill Sloman wrote:
On Saturday, September 26, 2020 at 3:20:43 PM UTC+10, boB wrote:
On Fri, 25 Sep 2020 09:31:40 +0200, Jeroen Belleman
jer...@nospam.please> wrote:

legg wrote:
On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <us...@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

That\'s a 5943000201 in the Fair-Rite catalog. Al = 375nH/n^0.5.

375nH/n^2


You\'d only need 16 turns x2 to get a 2x100uH common mode choke.

It\'s the right material for the application.

Yes.

Too many turns can eventually give diminishing returns due to too much
intra-winding capacitance.

You can work that out. Sixteen turns on a toroid sounds like a single layer winding, where the parallel capacitance tend to be around 1pF, which would make the coil parallel resonant at about 8MHz (very roughly).

Very roughly indeed, an octave out - I make 1pF 100uH resonant at 16MHz

Oops. I wasn\'t reading carefully enough. I got quite the wrong inductance, and seem to have plugged in the wrong capacitance too.

Repeating the calculation gives me 15.9MHz - which certainly isn\'t worth reporting as anything different from 16MHz.

A common mode choke is going to use a bifilar winding, which is to say a length of twisted pair, which has a very well-defined interwinding capacitance, which I\'m no longer game to try to work out.

Thanks for the correction .

> > As soon as you start stacking up layers of windings, life gets more difficult and you have to starting thinking about partitioning the winding into successive multi-layer chunks, where there isn\'t a lot of voltage difference within any one chunk.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Saturday, September 26, 2020 at 6:48:34 PM UTC+10, piglet wrote:

On 26/09/2020 09:12, Piotr Wyderski wrote:
Piglet wrote:

Very roughly indeed, an octave out - I make 1pF 100uH resonant at 16MHz

I would say an octave is good enough for a SWAG. Even a decade would
pass in most of the cases.

Best regards, Piotr
You are right when some information is missing but in this case all the
data was available to calculate better.

I agree with piglet. I\'m not in the least pleased with myself.

--
Bill Sloman, Sydney

 

[amdx]

On 9/24/2020 8:36 PM, bitrex wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.


but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

It was my understanding the that the point where u\' and u\" cross on a
permeability curve is where the material Q = 1.

https://www.fair-rite.com/43-material-data-sheet/ On this curve that
is at about 7MHz.
How do I reconcile that with the curve on this page.

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.
Mikek

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[legg]

On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote:

On 9/24/2020 8:36 PM, bitrex wrote:
The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.


but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

It was my understanding the that the point where u\' and u\" cross on a
permeability curve is where the material Q = 1.

https://www.fair-rite.com/43-material-data-sheet/ On this curve that
is at about 7MHz.
How do I reconcile that with the curve on this page.

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.
Mikek

There is no such thing as material \'Q\'.

When you assume subjective properties in
magnetics, you make a fool of you and me.

RL

 

[John S]

On 9/26/2020 10:33 AM, legg wrote:

On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote:

On 9/24/2020 8:36 PM, bitrex wrote:
The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.


but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

It was my understanding the that the point where u\' and u\" cross on a
permeability curve is where the material Q = 1.

https://www.fair-rite.com/43-material-data-sheet/ On this curve that
is at about 7MHz.
How do I reconcile that with the curve on this page.

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.
Mikek

There is no such thing as material \'Q\'.

When you assume subjective properties in
magnetics, you make a fool of you and me.

RL

I think the crossing point is where the resistance is equal to the
reactance. No?

If so, then the Q at that point is 1. No?

 

[legg]

On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org>
wrote:

On 9/26/2020 10:33 AM, legg wrote:
On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote:

On 9/24/2020 8:36 PM, bitrex wrote:
The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.


but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

It was my understanding the that the point where u\' and u\" cross on a
permeability curve is where the material Q = 1.

https://www.fair-rite.com/43-material-data-sheet/ On this curve that
is at about 7MHz.
How do I reconcile that with the curve on this page.

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.
Mikek

There is no such thing as material \'Q\'.

When you assume subjective properties in
magnetics, you make a fool of you and me.

RL


I think the crossing point is where the resistance is equal to the
reactance. No?

If so, then the Q at that point is 1. No?

The material itself doesn\'t have reactance. It does
have a bulk resistivity, but that isn\'t directly
related to core loss effects, though lossy materials
can often be identified by their low bulk resistance.

\"It was my understanding the that the point where u\' and u\"
cross on apermeability curve is where the material Q = 1.\"

- Refers to a graph constructed using measurements performed
on a predifined core shape and turns count, as comparative
reference information for the core material in question.
The graphical contents would change with a different core
shape or winding configuration - shifting this specific \'Q\'
point, without altering the material composition of the core.

Another common graph is for the single-turn bead, which
attempts to reduce winding effects on measurement of the
loss characteristic. Each bead size and shape will still
have its own curves, without alteration in the core
material type.

Anyone can stipulate that a Q factor exists for the relation
between any two measurable quantities. providing that its
definition is presented within the scope of the work.

In a non-resonant circuit, the term has little meaning,
as losses in the core are (non-linearly) dependent on the
amplitude of the peak flux excursion, and many other
inter-related physical factors of the core and winding.

RL

 

[Joe Gwinn]

On Sat, 26 Sep 2020 16:13:07 -0400, legg <legg@nospam.magma.ca> wrote:

On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org
wrote:

On 9/26/2020 10:33 AM, legg wrote:
On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote:

On 9/24/2020 8:36 PM, bitrex wrote:
The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.


but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

It was my understanding the that the point where u\' and u\" cross on a
permeability curve is where the material Q = 1.

https://www.fair-rite.com/43-material-data-sheet/ On this curve that
is at about 7MHz.
How do I reconcile that with the curve on this page.

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.
Mikek

There is no such thing as material \'Q\'.

When you assume subjective properties in
magnetics, you make a fool of you and me.

RL


I think the crossing point is where the resistance is equal to the
reactance. No?

If so, then the Q at that point is 1. No?

The material itself doesn\'t have reactance. It does
have a bulk resistivity, but that isn\'t directly
related to core loss effects, though lossy materials
can often be identified by their low bulk resistance.

\"It was my understanding the that the point where u\' and u\"
cross on apermeability curve is where the material Q = 1.\"

- Refers to a graph constructed using measurements performed
on a predifined core shape and turns count, as comparative
reference information for the core material in question.
The graphical contents would change with a different core
shape or winding configuration - shifting this specific \'Q\'
point, without altering the material composition of the core.

Another common graph is for the single-turn bead, which
attempts to reduce winding effects on measurement of the
loss characteristic. Each bead size and shape will still
have its own curves, without alteration in the core
material type.

Anyone can stipulate that a Q factor exists for the relation
between any two measurable quantities. providing that its
definition is presented within the scope of the work.

In a non-resonant circuit, the term has little meaning,
as losses in the core are (non-linearly) dependent on the
amplitude of the peak flux excursion, and many other
inter-related physical factors of the core and winding.

A lot of instruments to measure inductors and capacitors report Q, by
which they mean the ratio of reactance divided by resistance at the
chosen test frequency, well away from resonance.

Joe Gwinn

 

[server]

On Thu, 24 Sep 2020 21:36:53 -0400, bitrex <user@example.net> wrote:

The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.

but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

I\'ve tested some commercial AC-line CM chokes. I was surprised by how
little normal-mode DC current it takes to saturate the ones I tried.
They seem to assume that all AC loads are exactly DC balanced.




--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[legg]

On Sat, 26 Sep 2020 16:54:54 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:

On Sat, 26 Sep 2020 16:13:07 -0400, legg <legg@nospam.magma.ca> wrote:

On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org
wrote:

On 9/26/2020 10:33 AM, legg wrote:
On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote:

On 9/24/2020 8:36 PM, bitrex wrote:
The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.


but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

It was my understanding the that the point where u\' and u\" cross on a
permeability curve is where the material Q = 1.

https://www.fair-rite.com/43-material-data-sheet/ On this curve that
is at about 7MHz.
How do I reconcile that with the curve on this page.

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.
Mikek

There is no such thing as material \'Q\'.

When you assume subjective properties in
magnetics, you make a fool of you and me.

RL


I think the crossing point is where the resistance is equal to the
reactance. No?

If so, then the Q at that point is 1. No?

The material itself doesn\'t have reactance. It does
have a bulk resistivity, but that isn\'t directly
related to core loss effects, though lossy materials
can often be identified by their low bulk resistance.

\"It was my understanding the that the point where u\' and u\"
cross on apermeability curve is where the material Q = 1.\"

- Refers to a graph constructed using measurements performed
on a predifined core shape and turns count, as comparative
reference information for the core material in question.
The graphical contents would change with a different core
shape or winding configuration - shifting this specific \'Q\'
point, without altering the material composition of the core.

Another common graph is for the single-turn bead, which
attempts to reduce winding effects on measurement of the
loss characteristic. Each bead size and shape will still
have its own curves, without alteration in the core
material type.

Anyone can stipulate that a Q factor exists for the relation
between any two measurable quantities. providing that its
definition is presented within the scope of the work.

In a non-resonant circuit, the term has little meaning,
as losses in the core are (non-linearly) dependent on the
amplitude of the peak flux excursion, and many other
inter-related physical factors of the core and winding.

A lot of instruments to measure inductors and capacitors report Q, by
which they mean the ratio of reactance divided by resistance at the
chosen test frequency, well away from resonance.

Joe Gwinn

As long as they tell you what they\'re talking about, then
they can call it anything they want.

Q is not a characteristic of the core material.

RL

 

[John S]

On 9/26/2020 5:16 PM, legg wrote:

On Sat, 26 Sep 2020 16:54:54 -0400, Joe Gwinn <joegwinn@comcast.net
wrote:

On Sat, 26 Sep 2020 16:13:07 -0400, legg <legg@nospam.magma.ca> wrote:

On Sat, 26 Sep 2020 10:39:50 -0500, John S <Sophi.2@invalid.org
wrote:

On 9/26/2020 10:33 AM, legg wrote:
On Sat, 26 Sep 2020 07:41:41 -0500, amdx <amdx@knology.net> wrote:

On 9/24/2020 8:36 PM, bitrex wrote:
The article here says type 43 NiZn ferrite\'s resistive impedance exceeds
it\'s reactance at about 2MHz

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.


but I think that\'s a misprint, looks more like 15MHz:

https://www.nutsvolts.com/uploads/wygwam/NV_0715_Silver_Figure01.jpg

The data-sheet is here:

https://www.fair-rite.com/43-material-data-sheet/

I have a bunch of FT37-43s ferrite toroids on hand and I need a 100uH
common-mode choke for about 3 MHz, the calculator says about 30 turns
should give me that but I\'m unclear if this is an appropriate material

It was my understanding the that the point where u\' and u\" cross on a
permeability curve is where the material Q = 1.

https://www.fair-rite.com/43-material-data-sheet/ On this curve that
is at about 7MHz.
How do I reconcile that with the curve on this page.

https://www.nutsvolts.com/magazine/article/July2015_HamWorkbench#:~:text=Type%2043%20is%20one%20such,video%20cables%20use%20this%20mix.
Mikek

There is no such thing as material \'Q\'.

When you assume subjective properties in
magnetics, you make a fool of you and me.

RL


I think the crossing point is where the resistance is equal to the
reactance. No?

If so, then the Q at that point is 1. No?

The material itself doesn\'t have reactance. It does
have a bulk resistivity, but that isn\'t directly
related to core loss effects, though lossy materials
can often be identified by their low bulk resistance.

\"It was my understanding the that the point where u\' and u\"
cross on apermeability curve is where the material Q = 1.\"

- Refers to a graph constructed using measurements performed
on a predifined core shape and turns count, as comparative
reference information for the core material in question.
The graphical contents would change with a different core
shape or winding configuration - shifting this specific \'Q\'
point, without altering the material composition of the core.

Another common graph is for the single-turn bead, which
attempts to reduce winding effects on measurement of the
loss characteristic. Each bead size and shape will still
have its own curves, without alteration in the core
material type.

Anyone can stipulate that a Q factor exists for the relation
between any two measurable quantities. providing that its
definition is presented within the scope of the work.

In a non-resonant circuit, the term has little meaning,
as losses in the core are (non-linearly) dependent on the
amplitude of the peak flux excursion, and many other
inter-related physical factors of the core and winding.

A lot of instruments to measure inductors and capacitors report Q, by
which they mean the ratio of reactance divided by resistance at the
chosen test frequency, well away from resonance.

Joe Gwinn

As long as they tell you what they\'re talking about, then
they can call it anything they want.

Q is not a characteristic of the core material.

RL

Perhaps not. But as soon as you put a wire through the hole it has Q at
some point. What good is the core if it not used?

 

[Steve Wilson]

legg <legg@nospam.magma.ca> wrote:

On Sat, 26 Sep 2020 16:54:54 -0400, Joe Gwinn <joegwinn@comcast.net
wrote:

A lot of instruments to measure inductors and capacitors report Q, by
which they mean the ratio of reactance divided by resistance at the
chosen test frequency, well away from resonance.

Joe Gwinn

As long as they tell you what they\'re talking about, then
they can call it anything they want.

Q is not a characteristic of the core material.

RL

Many LCR meters report Q as a ratio of reactance divided by resistance.

For example, the Agilent / Keysight U1733C 100Hz/120Hz/1kHz/10kHz/100kHz
Handheld LCR Meter:

https://literature.cdn.keysight.com/litweb/pdf/U1731-90076.pdf