Planar Rogowski coils on PCB...

[Piotr Wyderski]

I have recently found these:

https://www.riccardofontanini.it/projects/rogowski/pdf/coilsplanar.pdf
https://eldorado.tu-dortmund.de/bitstream/2003/33955/1/S05.2.pdf

This might be worth a prototype PCB spin just to see how it performs.
Do you happen to have some practical experience with current sensors
like these and can share your insights?

This guy seems to have found a successful application:

https://youtu.be/v7vOZlklv2c?t=104

Best regards, Piotr

 

[John Larkin]

On Tue, 1 Sep 2020 13:48:56 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

I have recently found these:

https://www.riccardofontanini.it/projects/rogowski/pdf/coilsplanar.pdf
https://eldorado.tu-dortmund.de/bitstream/2003/33955/1/S05.2.pdf

This might be worth a prototype PCB spin just to see how it performs.
Do you happen to have some practical experience with current sensors
like these and can share your insights?

This guy seems to have found a successful application:

https://youtu.be/v7vOZlklv2c?t=104

Best regards, Piotr

Murata makes some cute little dc/dc converters where the windings are
all traces and vias. There is a ferrite toroid buried *inside* the PC
board.

https://www.dropbox.com/sh/zpig8jkn4nc8dys/AABCtke6gbAa0OYKhPWHLj6Ra?dl=0

A similar idea could make a current transformer.

 

[Piotr Wyderski]

John Larkin wrote:

Murata makes some cute little dc/dc converters where the windings are
all traces and vias. There is a ferrite toroid buried *inside* the PC
board.

Yes, there are modules like these, but it is still exotica. The Rogowski
coil does not use a core (that\'s the whole idea), so can be implemented
on standard PCB substrates. If the vendor can make a 4-layer PCB, they
can make this as well, without asking any additional questions.

I am tempted to prototype it just out of curiosity.

Best regards, Piotr

 

[Jan Panteltje]

On a sunny day (Wed, 2 Sep 2020 08:34:18 +0200) it happened Piotr Wyderski
<peter.pan@neverland.mil> wrote in <rined9$25eun$1@portraits.wsisiz.edu.pl>:

John Larkin wrote:

Murata makes some cute little dc/dc converters where the windings are
all traces and vias. There is a ferrite toroid buried *inside* the PC
board.

Yes, there are modules like these, but it is still exotica. The Rogowski
coil does not use a core (that\'s the whole idea), so can be implemented
on standard PCB substrates. If the vendor can make a 4-layer PCB, they
can make this as well, without asking any additional questions.

I am tempted to prototype it just out of curiosity.

Best regards, Piotr

It is nice, first I looked at the PCB from the top and tought
\'this cannot work\',
then I realized from the article it was a 3 D coil wound around the field lines..
Very nice!

 

[server]

On Wed, 2 Sep 2020 08:34:18 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

John Larkin wrote:

Murata makes some cute little dc/dc converters where the windings are
all traces and vias. There is a ferrite toroid buried *inside* the PC
board.

Yes, there are modules like these, but it is still exotica. The Rogowski
coil does not use a core (that\'s the whole idea), so can be implemented
on standard PCB substrates. If the vendor can make a 4-layer PCB, they
can make this as well, without asking any additional questions.

I am tempted to prototype it just out of curiosity.

Best regards, Piotr

Or buy a 3-cent current shunt!



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Piotr Wyderski]

jlarkin@highlandsniptechnology.com wrote:

> Or buy a 3-cent current shunt!

For a hundred of amps? Interesting.

Best regards, Piotr

 

[Piotr Wyderski]

Jan Panteltje wrote:

> Very nice!

Here is one more, likely by the guy from the movie:

https://www.riccardofontanini.it/projects/rogowski/pdf/6Wang.pdf

Best regards, Piotr

 

[Michal]

On 2020-09-01 13:48, Piotr Wyderski wrote:

I have recently found these:

https://www.riccardofontanini.it/projects/rogowski/pdf/coilsplanar.pdf
https://eldorado.tu-dortmund.de/bitstream/2003/33955/1/S05.2.pdf

This might be worth a prototype PCB spin just to see how it performs.
Do you happen to have some practical experience with current sensors
like these and can share your insights?

Hi Piotr,
please have a look here:
https://www.ti.com/lit/pdf/TIDUBV4A

some experiments with promising results were performed by my colleagues,
but unfortunately I can\'t share results

Best Regards

Michal

 

[Lasse Langwadt Christensen]

onsdag den 2. september 2020 kl. 16.28.09 UTC+2 skrev jla...@highlandsniptechnology.com:

On Wed, 2 Sep 2020 08:34:18 +0200, Piotr Wyderski
peter.pan@neverland.mil> wrote:

John Larkin wrote:

Murata makes some cute little dc/dc converters where the windings are
all traces and vias. There is a ferrite toroid buried *inside* the PC
board.

Yes, there are modules like these, but it is still exotica. The Rogowski
coil does not use a core (that\'s the whole idea), so can be implemented
on standard PCB substrates. If the vendor can make a 4-layer PCB, they
can make this as well, without asking any additional questions.

I am tempted to prototype it just out of curiosity.

Best regards, Piotr

Or buy a 3-cent current shunt!

isolated and for hundreds of amps?

 

[server]

On Wed, 2 Sep 2020 14:27:34 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

onsdag den 2. september 2020 kl. 16.28.09 UTC+2 skrev jla...@highlandsniptechnology.com:
On Wed, 2 Sep 2020 08:34:18 +0200, Piotr Wyderski
peter.pan@neverland.mil> wrote:

John Larkin wrote:

Murata makes some cute little dc/dc converters where the windings are
all traces and vias. There is a ferrite toroid buried *inside* the PC
board.

Yes, there are modules like these, but it is still exotica. The Rogowski
coil does not use a core (that\'s the whole idea), so can be implemented
on standard PCB substrates. If the vendor can make a 4-layer PCB, they
can make this as well, without asking any additional questions.

I am tempted to prototype it just out of curiosity.

Best regards, Piotr

Or buy a 3-cent current shunt!


isolated and for hundreds of amps?

Looks like the hundreds of amps is transient current in a cap. Use the
drop in a PCB trace or a bus bar. Transformer couple for isolation.
All that would cost about a dollar.

I guessed pretty close on this one:

https://www.dropbox.com/s/lulztcfar8o6sc8/P902_Shunts.jpg?raw=1

It measures 24.9 mOhms.

That would stand 100 amps for a reasonable transient. And I could have
used much smaller resistors.




--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[server]

On Wed, 2 Sep 2020 23:15:25 +0200, Michal <mbaszyns@ga.ze.ta.pl>
wrote:

On 2020-09-01 13:48, Piotr Wyderski wrote:
I have recently found these:

https://www.riccardofontanini.it/projects/rogowski/pdf/coilsplanar.pdf
https://eldorado.tu-dortmund.de/bitstream/2003/33955/1/S05.2.pdf

This might be worth a prototype PCB spin just to see how it performs.
Do you happen to have some practical experience with current sensors
like these and can share your insights?

Hi Piotr,
please have a look here:
https://www.ti.com/lit/pdf/TIDUBV4A

Seems like overkill to measure the current in a motor. In 50 ns.

They finally reveal the value of M in table 2. It has seven zeroes to
the right of the decimal point. Curious notation.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[legg]

On Tue, 1 Sep 2020 13:48:56 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

I have recently found these:

https://www.riccardofontanini.it/projects/rogowski/pdf/coilsplanar.pdf
https://eldorado.tu-dortmund.de/bitstream/2003/33955/1/S05.2.pdf

This might be worth a prototype PCB spin just to see how it performs.
Do you happen to have some practical experience with current sensors
like these and can share your insights?

This guy seems to have found a successful application:

https://youtu.be/v7vOZlklv2c?t=104

Best regards, Piotr

One of the major features of the rogowski coil is its flexibility
and its detachable physical termination, in portable instrumentation.

A printed circuit embodiment enforces physical limitations that,
in turn, severely restricts its uses - but you can\'t beat the cost
in a captive AC or low duty high current pulsed application, if you
can get it to fit.

For captive applications, it\'s hard to beat the ACSxxx pcb-mounted,
isolated sensors from Allegro, which will give you DC, as well,
for continuous, asymmetrical and bidirectional currents.

RL

 

[Piotr Wyderski]

legg wrote:

For captive applications, it\'s hard to beat the ACSxxx pcb-mounted,
isolated sensors from Allegro, which will give you DC, as well,
for continuous, asymmetrical and bidirectional currents.

DC measurement is indeed a great feature, but there is a problem at the
opposite end of the spectrum: the Hall effect sensors from Allegro are
good to 1MHz max, which might not be sufficient in some applications.
The Rogowski coil can easily go to 20MHz if one can afford a decent
opamp. But admittedly, no DC response.

The open-loop Hall sensors from Allegro are also susceptible to external
magnetic fields, down to DC (tested that the other day with ACS758).
They are excellent if simplicity is at a premium. Still, if I had to
actually *measure* something (either with accuracy or fast response in
mind), I would first consider the shunt approach suggested by John. A
fluxgate like the F03P050S05 would be my second choice, then a saturable
reactor, then a Hall. Another nuisance with the Allegro sensors (and
most others) is that the result is ratiometric, but they do their best
not to tell you where the midpoint is, according to them. It kills
differential interfacing instantly due to the unknown offset and
temperature drift it introduces. Is that one additional pin
cost-prohibitive?

There are magnetoresistive sensors as well, which can go to 2MHz:

https://www.sensitec.com/fileadmin/sensitec/Service_and_Support/Downloads/Product_Information/Brochures/SENSITEC_CMS3000_EN.pdf

but the resistance of their current path is about 10mOhms. That makes
using them pointless, as a shunt of this value would allow me to measure
the current with much better accuracy and speed. Not sure what problem
they are trying to solve with that part.

Best regards, Piotr