where is pin 1?...

[John Larkin]

On Fri, 25 Aug 2023 05:11:09 -0000 (UTC), Jasen Betts
<usenet@revmaps.no-ip.org> wrote:

On 2023-08-24, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:

This inductor data sheet numbers the six pins, we suspect using a
european third-angle projection, but the part has no hint of where pin
1 might be.

https://www.digikey.com/en/products/detail/schaffner-emc-inc/RT8132-8-4M8/8345234

It doesn\'t matter, but our production and QC people will pester us
endlessly about it.

yeah... I can\'t think of a cure for that.

Do you get the same grief for non-polar capacitors?

Only if the cap is marked. Film caps used to sometimes have an
\"outside foil\" band but smt parts don\'t.

If they did, we\'d put a dot on the silk.

The drawings in the data sheet are inaccurate too.


On this connector,

https://www.digikey.com/en/products/detail/phoenix-contact/1809102/3439835

https://www.digikey.com/en/products/detail/phoenix-contact/1861726/9349730

neither the header nor its mate suggests a pin 1, on the data sheet or
on the parts. It matters.

They have a better datasheet on their website.

https://www.phoenixcontact.com/en-nz/products/pcb-header-mstba-25-5-g-508-lr-1809102
(see page 7)

Horrible web site!

OK, but neither the actual part nor its mate has any hint of which end
is pin 1.

The data sheets on Digikey and Mouser seem to be auto-generated on
demand by a net-very-smart bot.

 

[Anthony William Sloman]

On Saturday, August 26, 2023 at 12:35:35 AM UTC+10, John Larkin wrote:

On Fri, 25 Aug 2023 09:48:10 -0400, legg <le...@nospam.magma.ca> wrote:
On Thu, 24 Aug 2023 09:32:25 -0700, John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
On Thu, 24 Aug 2023 11:55:35 -0400, legg <le...@nospam.magma.ca> wrote:
On Thu, 24 Aug 2023 06:48:48 -0700 (PDT), Anthony William Sloman <bill.....@ieee.org> wrote:

On Thursday, August 24, 2023 at 12:44:21?PM UTC+10, John Larkin wrote:

He managed to agree with me and call me stupid at the same time. I usually ignore him but you\'ve got to admire creativity at that level.

What I posted was

\"Actually, it doesn\'t. These are just common modes chokes on a single core with two or three coils of equal inductance, and they are all wound in the same sense. It doesn\'t make any difference which way around you mount them, as anybody who understood inductors would know. Explaining this to people who don\'t understand inductors gets tedious, which is presumably what John Larkin is bitching about. \"

That isn\'t calling you stupid. It may not contain the fulsome flattery you seem to think you deserve, but it does explicitly suggest that you do understand inductors, which is quite explicitly not calling you stupid. Quite a few non-stupid people don\'t understand inductors. Most people don\'t need to bother.

--
Bill Sloman, Sydney

 

[John Larkin]

On Fri, 25 Aug 2023 09:48:10 -0400, legg <legg@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 09:32:25 -0700, John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote:

On Thu, 24 Aug 2023 11:55:35 -0400, legg <legg@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 06:48:48 -0700 (PDT), Anthony William Sloman
bill.sloman@ieee.org> wrote:

On Thursday, August 24, 2023 at 12:44:21?PM UTC+10, John Larkin wrote:
This inductor data sheet numbers the six pins, we suspect using a
european third-angle projection, but the part has no hint of where pin
1 might be.

https://www.digikey.com/en/products/detail/schaffner-emc-inc/RT8132-8-4M8/8345234

It doesn\'t matter, but our production and QC people will pester us
endlessly about it.

The drawings in the data sheet are inaccurate too.


On this connector,

https://www.digikey.com/en/products/detail/phoenix-contact/1809102/3439835

https://www.digikey.com/en/products/detail/phoenix-contact/1861726/9349730

neither the header nor its mate suggests a pin 1, on the data sheet or
on the parts. It matters.

Actually, it doesn\'t. these. These are just common modes chokes on a single core with two or three coils of equal inductance, and they are all wound in the same sense. It doesn\'t make any difference which way around you mount them, as anybody who understood inductors would know. Explaining this to people who don\'t understand inductors gets tedious, which is presumably what John Larkin is bitching about.

They\'re supposed to be idiot-proof, but with EMC, physical
placement of starts and finishes on the physical body
can have unexpected benefits/pitfalls.

The CM choke works at any rotation, as I noted and Sloman ignored. The
only problem is not getting pestered by production and QC, namely
\"where is pin 1?\" We\'ll have to note in the production documentation
IT DOESN\'T MATTER. We deliberately didn\'t include a pin1 dot on the
PCB silk.

Sloman is never pestered by production or QC. His only mission is life
is to tell everyone else how stupid they are.



There are only a rare few EMC choke designs that are suitable
for automated fab, so you\'re often at the mercy of visual
inspection of manual windings, for \'internal\' lead dressing
or winding direction, though phasing may be accurate and
measurable leakage terms by the book.

RL

The leakage inductance is tiny on that choke, like 15uH on one winding
with the other two shorted. CM chokes tend to use very hi-mu core
material, which means they saturate at very low levels of non-balanced
current. One can be fooled by distributor searches into thinking these
are really good multi-winding conventional inductors.

I guess they might be good transformers. Hey, maybe I can use a cool
Coilcraft planar transformer instead of that monster.

The 18uH leakage inductance is free and works om DM currents. It\'s
also the \'oick-up antenna\' for nuisance local EMI re-radiation in
just the exact wrong place - in the filter hardware itself - often
justifying local physical screening in hardware $ $ $ .

CM chokes are specified for inductance and for max current, which
seems to be purely thermal.

People never seem to specify actual core saturation currents; looks
like they assume that the net flux is zero. They typically saturate at
a few per cent of datasheet current.

One could test the current rating without saturating a 2-wire CM
choke, but I can\'t think of a way to test a 3-winding choke without
saturating the core.

 

[Anthony William Sloman]

On Saturday, August 26, 2023 at 1:54:46 AM UTC+10, John Larkin wrote:

On Fri, 25 Aug 2023 09:48:10 -0400, legg <le...@nospam.magma.ca> wrote:
On Thu, 24 Aug 2023 09:32:25 -0700, John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
On Thu, 24 Aug 2023 11:55:35 -0400, legg <le...@nospam.magma.ca> wrote:
On Thu, 24 Aug 2023 06:48:48 -0700 (PDT), Anthony William Sloman <bill.....@ieee.org> wrote:
On Thursday, August 24, 2023 at 12:44:21?PM UTC+10, John Larkin wrote:

<snip>

> CM chokes are specified for inductance and for max current, which seems to be purely thermal.

Presumably it is the Curie temperature of the core that matters, and you can measure that in an oven - inductance will drop with rising temperature and fall away very rapidly as you get close to the Curie temperature.

People never seem to specify actual core saturation currents; looks like they assume that the net flux is zero. They typically saturate at a few per cent of datasheet current.

One could test the current rating without saturating a 2-wire CM choke, but I can\'t think of a way to test a 3-winding choke without saturating the core.

All you need to work out is how much heat you can get away with dissipating in the windings before you push the core above it\'s Curie temperature.

You will be able to dissipate more heat in all three windings before you overheat the core than you could in just two, but there won\'t be much in it.

It\'s pretty much a single solid thermally conductive lump.

Sticking a thermistor on the core through the plastic former will give you it\'s temperature explicitly.

--
Bill Sloman, Sydney

 

[TTman]

Cheers

Phil Hobbs

At least tubes had keys. You can load an IC wrong two or four ways.
Why are so many things symmetric?

That 3 way choke doesn\'t look symmetrical to me in the PCB pin layout.....

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

 

[John Larkin]

On Fri, 25 Aug 2023 22:56:50 +0100, TTman <kraken.sankey@gmail.com>
wrote:

Cheers

Phil Hobbs

At least tubes had keys. You can load an IC wrong two or four ways.
Why are so many things symmetric?

That 3 way choke doesn\'t look symmetrical to me in the PCB pin layout.....

It\'s 3-way, 120 degree, symmetric. But there\'s no way to install it
wrong... it always works.

 

[legg]

On Fri, 25 Aug 2023 08:54:21 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:

On Fri, 25 Aug 2023 09:48:10 -0400, legg <legg@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 09:32:25 -0700, John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote:

On Thu, 24 Aug 2023 11:55:35 -0400, legg <legg@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 06:48:48 -0700 (PDT), Anthony William Sloman
bill.sloman@ieee.org> wrote:

On Thursday, August 24, 2023 at 12:44:21?PM UTC+10, John Larkin wrote:
This inductor data sheet numbers the six pins, we suspect using a
european third-angle projection, but the part has no hint of where pin
1 might be.

https://www.digikey.com/en/products/detail/schaffner-emc-inc/RT8132-8-4M8/8345234

It doesn\'t matter, but our production and QC people will pester us
endlessly about it.

The drawings in the data sheet are inaccurate too.


On this connector,

https://www.digikey.com/en/products/detail/phoenix-contact/1809102/3439835

https://www.digikey.com/en/products/detail/phoenix-contact/1861726/9349730

neither the header nor its mate suggests a pin 1, on the data sheet or
on the parts. It matters.

Actually, it doesn\'t. these. These are just common modes chokes on a single core with two or three coils of equal inductance, and they are all wound in the same sense. It doesn\'t make any difference which way around you mount them, as anybody who understood inductors would know. Explaining this to people who don\'t understand inductors gets tedious, which is presumably what John Larkin is bitching about.

They\'re supposed to be idiot-proof, but with EMC, physical
placement of starts and finishes on the physical body
can have unexpected benefits/pitfalls.

The CM choke works at any rotation, as I noted and Sloman ignored. The
only problem is not getting pestered by production and QC, namely
\"where is pin 1?\" We\'ll have to note in the production documentation
IT DOESN\'T MATTER. We deliberately didn\'t include a pin1 dot on the
PCB silk.

Sloman is never pestered by production or QC. His only mission is life
is to tell everyone else how stupid they are.



There are only a rare few EMC choke designs that are suitable
for automated fab, so you\'re often at the mercy of visual
inspection of manual windings, for \'internal\' lead dressing
or winding direction, though phasing may be accurate and
measurable leakage terms by the book.

RL

The leakage inductance is tiny on that choke, like 15uH on one winding
with the other two shorted. CM chokes tend to use very hi-mu core
material, which means they saturate at very low levels of non-balanced
current. One can be fooled by distributor searches into thinking these
are really good multi-winding conventional inductors.

I guess they might be good transformers. Hey, maybe I can use a cool
Coilcraft planar transformer instead of that monster.

The 18uH leakage inductance is free and works om DM currents. It\'s
also the \'oick-up antenna\' for nuisance local EMI re-radiation in
just the exact wrong place - in the filter hardware itself - often
justifying local physical screening in hardware $ $ $ .


CM chokes are specified for inductance and for max current, which
seems to be purely thermal.

People never seem to specify actual core saturation currents; looks
like they assume that the net flux is zero. They typically saturate at
a few per cent of datasheet current.

One could test the current rating without saturating a 2-wire CM
choke, but I can\'t think of a way to test a 3-winding choke without
saturating the core.

Ferrite cores are thermally limited to < curie temp, with the
higher permeability types having the lowest limits (<110C).

If it\'s an amorphous core matl, that isn\'t an issue, but Permeability
drops with current rather rapidly in ungapped structures of any form.

You can run DC current through two windings in a loop with inductive
decoupling while measuring L on the 3rd to get an idea of whats going
on during lower frequency imbalance to your common mode element..

This choke cannot force net zero flux - it merely assumes that there
is no 4th path. If your inverter \'wiggles\' are large and low-
frequency, RF will burst through on the peak imbalance.

RL

 

[whit3rd]

On Thursday, August 24, 2023 at 9:32:48 AM UTC-7, John Larkin wrote:

The leakage inductance is tiny on that choke, like 15uH on one winding
with the other two shorted. CM chokes tend to use very hi-mu core
material, which means they saturate at very low levels of non-balanced
current. One can be fooled by distributor searches into thinking these
are really good multi-winding conventional inductors.

I guess they might be good transformers. Hey, maybe I can use a cool
Coilcraft planar transformer instead of that monster.

CM chokes can use very lossy magnetic material and still
do their job well; it could be a good transformer if you use
it as a current transformer, but not as an AC voltage source.
Most \'planar transformer\' applications DO NOT work well with
lossy magnetics. RF would cook \'em.

 

[Anthony William Sloman]

On Saturday, August 26, 2023 at 1:54:46 AM UTC+10, John Larkin wrote:

On Fri, 25 Aug 2023 09:48:10 -0400, legg <le...@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 09:32:25 -0700, John Larkin
jla...@highlandSNIPMEtechnology.com> wrote:

On Thu, 24 Aug 2023 11:55:35 -0400, legg <le...@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 06:48:48 -0700 (PDT), Anthony William Sloman
bill....@ieee.org> wrote:

On Thursday, August 24, 2023 at 12:44:21?PM UTC+10, John Larkin wrote:
This inductor data sheet numbers the six pins, we suspect using a
european third-angle projection, but the part has no hint of where pin
1 might be.

https://www.digikey.com/en/products/detail/schaffner-emc-inc/RT8132-8-4M8/8345234

It doesn\'t matter, but our production and QC people will pester us
endlessly about it.

The drawings in the data sheet are inaccurate too.


On this connector,

https://www.digikey.com/en/products/detail/phoenix-contact/1809102/3439835

https://www.digikey.com/en/products/detail/phoenix-contact/1861726/9349730

neither the header nor its mate suggests a pin 1, on the data sheet or
on the parts. It matters.

Actually, it doesn\'t. these. These are just common modes chokes on a single core with two or three coils of equal inductance, and they are all wound in the same sense. It doesn\'t make any difference which way around you mount them, as anybody who understood inductors would know. Explaining this to people who don\'t understand inductors gets tedious, which is presumably what John Larkin is bitching about.

They\'re supposed to be idiot-proof, but with EMC, physical
placement of starts and finishes on the physical body
can have unexpected benefits/pitfalls.

The CM choke works at any rotation, as I noted and Sloman ignored. The
only problem is not getting pestered by production and QC, namely
\"where is pin 1?\" We\'ll have to note in the production documentation
IT DOESN\'T MATTER. We deliberately didn\'t include a pin1 dot on the
PCB silk.

Sloman is never pestered by production or QC. His only mission is life
is to tell everyone else how stupid they are.



There are only a rare few EMC choke designs that are suitable
for automated fab, so you\'re often at the mercy of visual
inspection of manual windings, for \'internal\' lead dressing
or winding direction, though phasing may be accurate and
measurable leakage terms by the book.

RL

The leakage inductance is tiny on that choke, like 15uH on one winding
with the other two shorted. CM chokes tend to use very hi-mu core
material, which means they saturate at very low levels of non-balanced
current. One can be fooled by distributor searches into thinking these
are really good multi-winding conventional inductors.

I guess they might be good transformers. Hey, maybe I can use a cool
Coilcraft planar transformer instead of that monster.

The 18uH leakage inductance is free and works om DM currents. It\'s
also the \'oick-up antenna\' for nuisance local EMI re-radiation in
just the exact wrong place - in the filter hardware itself - often
justifying local physical screening in hardware $ $ $ .

CM chokes are specified for inductance and for max current, which
seems to be purely thermal.

People never seem to specify actual core saturation currents; looks
like they assume that the net flux is zero. They typically saturate at
a few per cent of datasheet current.

One could test the current rating without saturating a 2-wire CM
choke, but I can\'t think of a way to test a 3-winding choke without
saturating the core.

Neither could I at 2:19am local time. As soon as I\'d gone to bed I realised that three sine waves of identical frequency and amplitude but phased 120 degrees apart would do the job.

The trignometric identity you need to prove it is sin(a+b) = sin(a).cos(b) + sin(b). cos(a)

--
Bill Sloman, Sydney

 

[Anthony William Sloman]

On Saturday, August 26, 2023 at 3:57:07 PM UTC+10, Anthony William Sloman wrote:

On Saturday, August 26, 2023 at 1:54:46 AM UTC+10, John Larkin wrote:
On Fri, 25 Aug 2023 09:48:10 -0400, legg <le...@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 09:32:25 -0700, John Larkin
jla...@highlandSNIPMEtechnology.com> wrote:

On Thu, 24 Aug 2023 11:55:35 -0400, legg <le...@nospam.magma.ca> wrote:

On Thu, 24 Aug 2023 06:48:48 -0700 (PDT), Anthony William Sloman
bill....@ieee.org> wrote:

On Thursday, August 24, 2023 at 12:44:21?PM UTC+10, John Larkin wrote:
This inductor data sheet numbers the six pins, we suspect using a
european third-angle projection, but the part has no hint of where pin
1 might be.

https://www.digikey.com/en/products/detail/schaffner-emc-inc/RT8132-8-4M8/8345234

It doesn\'t matter, but our production and QC people will pester us
endlessly about it.

The drawings in the data sheet are inaccurate too.


On this connector,

https://www.digikey.com/en/products/detail/phoenix-contact/1809102/3439835

https://www.digikey.com/en/products/detail/phoenix-contact/1861726/9349730

neither the header nor its mate suggests a pin 1, on the data sheet or
on the parts. It matters.

Actually, it doesn\'t. these. These are just common modes chokes on a single core with two or three coils of equal inductance, and they are all wound in the same sense. It doesn\'t make any difference which way around you mount them, as anybody who understood inductors would know. Explaining this to people who don\'t understand inductors gets tedious, which is presumably what John Larkin is bitching about.

They\'re supposed to be idiot-proof, but with EMC, physical
placement of starts and finishes on the physical body
can have unexpected benefits/pitfalls.

The CM choke works at any rotation, as I noted and Sloman ignored. The
only problem is not getting pestered by production and QC, namely
\"where is pin 1?\" We\'ll have to note in the production documentation
IT DOESN\'T MATTER. We deliberately didn\'t include a pin1 dot on the
PCB silk.

Sloman is never pestered by production or QC. His only mission is life
is to tell everyone else how stupid they are.



There are only a rare few EMC choke designs that are suitable
for automated fab, so you\'re often at the mercy of visual
inspection of manual windings, for \'internal\' lead dressing
or winding direction, though phasing may be accurate and
measurable leakage terms by the book.

RL

The leakage inductance is tiny on that choke, like 15uH on one winding
with the other two shorted. CM chokes tend to use very hi-mu core
material, which means they saturate at very low levels of non-balanced
current. One can be fooled by distributor searches into thinking these
are really good multi-winding conventional inductors.

I guess they might be good transformers. Hey, maybe I can use a cool
Coilcraft planar transformer instead of that monster.

The 18uH leakage inductance is free and works om DM currents. It\'s
also the \'oick-up antenna\' for nuisance local EMI re-radiation in
just the exact wrong place - in the filter hardware itself - often
justifying local physical screening in hardware $ $ $ .

CM chokes are specified for inductance and for max current, which
seems to be purely thermal.

People never seem to specify actual core saturation currents; looks
like they assume that the net flux is zero. They typically saturate at
a few per cent of datasheet current.

One could test the current rating without saturating a 2-wire CM
choke, but I can\'t think of a way to test a 3-winding choke without
saturating the core.

Neither could I at 2:19am local time. As soon as I\'d gone to bed I realised that three sine waves of identical frequency and amplitude but phased 120 degrees apart would do the job.

The trignometric identity you need to prove it is sin(a+b) = sin(a).cos(b) + sin(b). cos(a)

So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

--
Bill Sloman, Sydney

 

[legg]

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
<bill.sloman@ieee.org> wrote:


>So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

It must be highly provoking, all that silence.

RL

 

[Anthony William Sloman]

On Tuesday, August 29, 2023 at 11:17:22 PM UTC+10, legg wrote:

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
bill....@ieee.org> wrote:

So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself.

It must be highly provoking, all that silence.

On the contrary, if John Larkin provided more of it, I\'d be appreciably happier. On this particular occasion he had come up with a question worth answering, which is rare, so I\'ve missed a rare chance to contribute something constructive.

--
Bill Sloman, Sydney

 

[John Larkin]

On Tue, 29 Aug 2023 09:20:09 -0400, legg <legg@nospam.magma.ca> wrote:

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
bill.sloman@ieee.org> wrote:


So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

It must be highly provoking, all that silence.

RL

The copper-loss based current rating, the thermal rating, can be done
with the windings in series, and ignore saturation. And the series
connction can reveal saturation behavior too, and I guess that\'s all I
need to know. I\'ll chip a bit of the core and see if it\'s ferrite or
powdered iron; it\'s sure heavy.

Sloman is just an insecure insult generator, and he\'d rather insult
than either learn or be right. There\'s no point on wasting time with
idea-free toads like that.

 

[Anthony William Sloman]

On Wednesday, August 30, 2023 at 1:20:29 AM UTC+10, John Larkin wrote:

On Tue, 29 Aug 2023 09:20:09 -0400, legg <le...@nospam.magma.ca> wrote:

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
bill....@ieee.org> wrote:


So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

It must be highly provoking, all that silence.

The copper-loss based current rating, the thermal rating, can be done
with the windings in series, and ignore saturation. And the series
connection can reveal saturation behavior too, and I guess that\'s all I
need to know. I\'ll chip a bit of the core and see if it\'s ferrite or
powdered iron; it\'s sure heavy.

What you said - at one point - was

\"One could test the current rating without saturating a 2-wire CM choke, but I can\'t think of a way to test a 3-winding choke without saturating the core.\"

Neither could I when I first looked at your post, but after I\'d slept on it I realised that feeding three phases of the same sine wave, spaced 120 degrees apart would do the same job on a 3-winding choke that two phases spaced 180 degrees apart do on a 2-winding choke.

> Sloman is just an insecure insult generator, and he\'d rather insult than either learn or be right.

There\'s no insult in that particular observation - or at least none that I can detect. I think I learnt something, and I\'m tolerably sure that the observation is correct.

> There\'s no point on wasting time with idea-free toads like that.

That does seem to be an idea that you didn\'t manage to come up with, so I may not be quite as idea-free as you like to think. I\'ve got a couple of patents - not a many as the seriously creative people I\'ve known - so I\'d guess that I\'m not entirely idea-free.

Getting help when you need it isn\'t an ego-boosting exercise, but it can save quite a bit of time.

--
Bill Sloman, Sydney

 

[legg]

On Tue, 29 Aug 2023 08:20:06 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:

On Tue, 29 Aug 2023 09:20:09 -0400, legg <legg@nospam.magma.ca> wrote:

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
bill.sloman@ieee.org> wrote:


So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

It must be highly provoking, all that silence.

RL

The copper-loss based current rating, the thermal rating, can be done
with the windings in series, and ignore saturation. And the series
connction can reveal saturation behavior too, and I guess that\'s all I
need to know. I\'ll chip a bit of the core and see if it\'s ferrite or
powdered iron; it\'s sure heavy.

If series windings are loaded out of phase, the effect of any
flux imbalance (due to leakage) AND thermals can be monitored
on the third winding.

RL

 

[legg]

On Tue, 29 Aug 2023 08:20:06 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:

<snip>

I\'ll chip a bit of the core and see if it\'s ferrite or
powdered iron; it\'s sure heavy.

Judging from the Al values, It is probably ferrite -
amorphous parts would be roughly 10x for same turns
count, but there seems to be a lot of plastic present
in the core volume. Weight suggests amorphous matl.

Iron dust is not used where high permeability is the
criterion.

RL

 

[John Larkin]

On Wed, 30 Aug 2023 08:04:49 -0400, legg <legg@nospam.magma.ca> wrote:

On Tue, 29 Aug 2023 08:20:06 -0700, John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote:

On Tue, 29 Aug 2023 09:20:09 -0400, legg <legg@nospam.magma.ca> wrote:

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
bill.sloman@ieee.org> wrote:


So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

It must be highly provoking, all that silence.

RL

The copper-loss based current rating, the thermal rating, can be done
with the windings in series, and ignore saturation. And the series
connction can reveal saturation behavior too, and I guess that\'s all I
need to know. I\'ll chip a bit of the core and see if it\'s ferrite or
powdered iron; it\'s sure heavy.

If series windings are loaded out of phase, the effect of any
flux imbalance (due to leakage) AND thermals can be monitored
on the third winding.

RL

Given the three separate clumps of windings, the leakage inductance,
one winding measured with the other two shorted, is an impressively
low 15 uH. Seems like common-mode chokes use very hi-mu cores.

In my application, I\'d actually appreciate more leakage L as part of
my EMI filters. The waveforms are ghastly.

 

[legg]

On Wed, 30 Aug 2023 06:26:43 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:

On Wed, 30 Aug 2023 08:04:49 -0400, legg <legg@nospam.magma.ca> wrote:

On Tue, 29 Aug 2023 08:20:06 -0700, John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote:

On Tue, 29 Aug 2023 09:20:09 -0400, legg <legg@nospam.magma.ca> wrote:

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
bill.sloman@ieee.org> wrote:


So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

It must be highly provoking, all that silence.

RL

The copper-loss based current rating, the thermal rating, can be done
with the windings in series, and ignore saturation. And the series
connction can reveal saturation behavior too, and I guess that\'s all I
need to know. I\'ll chip a bit of the core and see if it\'s ferrite or
powdered iron; it\'s sure heavy.

If series windings are loaded out of phase, the effect of any
flux imbalance (due to leakage) AND thermals can be monitored
on the third winding.

RL

Given the three separate clumps of windings, the leakage inductance,
one winding measured with the other two shorted, is an impressively
low 15 uH. Seems like common-mode chokes use very hi-mu cores.

In my application, I\'d actually appreciate more leakage L as part of
my EMI filters. The waveforms are ghastly.

CM chokes, working with safety-limited capacitor values,
are largely ineffective outside a 150Kz-1mHz range.

The leakage, working on DM currents can use larger capacitors,
if these don\'t contribute to pick-up loop area. This is in
roughly the same frequency range - but unwise component
values can produce peaking in the suppression band as CM and
DM components react with each other and their series/prallel
combinations.

Have you got a 3 phase LISN? No point in guessing if you can
see effects iteratively.

RL

 

[John Larkin]

On Wed, 30 Aug 2023 19:28:19 -0400, legg <legg@nospam.magma.ca> wrote:

On Wed, 30 Aug 2023 06:26:43 -0700, John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote:

On Wed, 30 Aug 2023 08:04:49 -0400, legg <legg@nospam.magma.ca> wrote:

On Tue, 29 Aug 2023 08:20:06 -0700, John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote:

On Tue, 29 Aug 2023 09:20:09 -0400, legg <legg@nospam.magma.ca> wrote:

On Mon, 28 Aug 2023 06:19:40 -0700 (PDT), Anthony William Sloman
bill.sloman@ieee.org> wrote:


So I gave John Larkin his answer but he won\'t notice it because he has got me kill-filed. Sad, when he didn\'t know enough to work it out for himself

It must be highly provoking, all that silence.

RL

The copper-loss based current rating, the thermal rating, can be done
with the windings in series, and ignore saturation. And the series
connction can reveal saturation behavior too, and I guess that\'s all I
need to know. I\'ll chip a bit of the core and see if it\'s ferrite or
powdered iron; it\'s sure heavy.

If series windings are loaded out of phase, the effect of any
flux imbalance (due to leakage) AND thermals can be monitored
on the third winding.

RL

Given the three separate clumps of windings, the leakage inductance,
one winding measured with the other two shorted, is an impressively
low 15 uH. Seems like common-mode chokes use very hi-mu cores.

In my application, I\'d actually appreciate more leakage L as part of
my EMI filters. The waveforms are ghastly.

CM chokes, working with safety-limited capacitor values,
are largely ineffective outside a 150Kz-1mHz range.

The leakage, working on DM currents can use larger capacitors,
if these don\'t contribute to pick-up loop area. This is in
roughly the same frequency range - but unwise component
values can produce peaking in the suppression band as CM and
DM components react with each other and their series/prallel
combinations.

Have you got a 3 phase LISN? No point in guessing if you can
see effects iteratively.

RL

I\'m not using this on a conventional AC power line. My box is a power
source, a 3-phase permanent-magnet alternator simulator, and it drives
a FADEC shorting/shunt regulator. Simulation shows a 6-amp RMS ground
loop, and the 3-leg CM choke reduces that to 100 mA.

The choke is a horrible beast to put on a PC board.

 

[legg]

On Wed, 30 Aug 2023 17:41:54 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:

<snip>

Given the three separate clumps of windings, the leakage inductance,
one winding measured with the other two shorted, is an impressively
low 15 uH. Seems like common-mode chokes use very hi-mu cores.

In my application, I\'d actually appreciate more leakage L as part of
my EMI filters. The waveforms are ghastly.

CM chokes, working with safety-limited capacitor values,
are largely ineffective outside a 150Kz-1mHz range.

The leakage, working on DM currents can use larger capacitors,
if these don\'t contribute to pick-up loop area. This is in
roughly the same frequency range - but unwise component
values can produce peaking in the suppression band as CM and
DM components react with each other and their series/prallel
combinations.

Have you got a 3 phase LISN? No point in guessing if you can
see effects iteratively.

RL

I\'m not using this on a conventional AC power line. My box is a power
source, a 3-phase permanent-magnet alternator simulator, and it drives
a FADEC shorting/shunt regulator. Simulation shows a 6-amp RMS ground
loop, and the 3-leg CM choke reduces that to 100 mA.

The choke is a horrible beast to put on a PC board.

Aviation regs are abundant, so you should look up actual requirements,
standards and test gear.

RL