Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel
[snip]
The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model,
[snip]

... I had to drill a hole in the wall of the physical model.

Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

Regards,
Va1erian

Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

Regards,
Va1erian

Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

Regards,
Va1erian

va1erian@mail.ru (va1erian@mail.ru) wrote:

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

I aready told you how.

1/2" high speed steel drill bit and drill followed by an extension
cord.

va1erian@mail.ru wrote:
Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

This makes no sense to me. If you can drill a hole to
permit the passage of magnetic flux, why not just run
insulated wires through the hole (presuming you can seal
adequately around the wires afterward) at much better than
10% efficiency?

BTW, what gas(es) or liquid(s) does the vessel contain at
what pressure?

Also, what sort of steel is the tank made of? If it's
noticeablly dissipative it may be to your advantage to
fabricate pole pieces (of soft iron) that can be bolted to
the inside of the vessel so as to direct the field where you
want it. Does the vessel _have_ to be steel? Do you have any
choice in this?

Finally, can you tell us exactly what you're trying to do
with that one watt? Is a magnetic field essential, or merely
a means to an end?

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

This makes no sense to me. If you can drill a hole to
permit the passage of magnetic flux, why not just run
insulated wires through the hole (presuming you can seal
adequately around the wires afterward) at much better than
10% efficiency?

Jim Klein <jameseklein@earthlink.net> writes:
va1erian@mail.ru (va1erian@mail.ru) wrote:

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

I aready told you how.

1/2" high speed steel drill bit and drill followed by an extension
cord. :-)

You're being very generous with the size to transfer 1 W.

This OP reads like a blond joke: The blond needs to transfer
energy into a sealed container but can't get the magnetic
flux to pass efficiently so drills a hole to help.

Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

Regards,
Va1erian

Valerian, there is an approach which doesn't require you to drill a hole >through the vessel in order to transmit information into the interior of the >vessel. The drawback is that it most likely requires more than 1 watt of power. The
approach is the following: On the transmit side form two concentric
coils. The
first set is used to generate a large dc field in the metal so that
it becomes >magnetically saturated. This will reduce the permeability

"va1erian@mail.ru" wrote:

Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

Regards,
Va1erian

If the bottle can be made of stainless steel, that is both non-magnetic
and
a fairly poor conductor, so you can use induction without too much
eddy-current
loss. You will have to design the coils and operating frequency to
minimize
such losses. Not something I can tell you how to do here. If you want
a more elaborate answer, I charge $250/hr for consulting.


--
Julian V. Noble
Professor Emeritus of Physics
jvn@spamfree.virginia.edu
^^^^^^^^
http://galileo.phys.virginia.edu/~jvn/

"Science knows only one commandment: contribute to science."
-- Bertolt Brecht, "Galileo".

The reason for these groups I thought were to get information without having
to pay people like you. IMO

Shawn
"Julian V. Noble" <jvn@nowhere.virginia.edu> wrote in message
news:3F96D50A.980C320A@nowhere.virginia.edu...

"va1erian@mail.ru" wrote:

Dear everyone,

I am doing a project to transfer electrical energy (about 1 W, pulsed)
through the metal wall (5-10 mm thick) of a pressurised vessel with an
efficiency 10%. I have considered the options to transfer acoustically
or optically, but the only suitable method turned out to be the
magnetic one. A primary coil on one side of the wall is fed with
pulsing/AC current, the resulting pulsing/AC magnetic field is
transferred through the metal wall, and the secondary coil on the
other side transforms the magnetic field into electrical current.

The only problem was that the steel wall absorbed all of the magnetic
field. I had to drill a hole in the wall of the physical model, so
that to allow the passage of the magnetic field. I inserted the
primary coil into the hole perpendicularly to the wall, and put the
secondary coil behind the wall with its axes parallel to the wall (for
certain reasons). Without the metal wall, the configuration of the
primary/secondary coil worked fine. But the introduction of the wall
into the system brought the voltage in the secondary coil close to
zero. It got me thinking -- I decided that even if the magnetic field
lines could get through the hole in the wall along the inserted coil
core, the lines had to return to the other magnetic pole of the
primary coil. And this was where the metal wall was the barrier to the
lines ! I thought that I would have to enlarge the hole and introduce
an air (magnetically easily penetratable) gap between the primary coil
and surrounding metal.

The question is, how large the hole has to be, so that to allow the
return passage of the magnetic field lines into the opposite pole of
the primary coil ? I thought I could use a simulation package to
analyse the distribution of magnetic lines, and thus I could find out
the effect of the size of the wall's hole on the efficacy of
transmission of magnetic energy through that hole. Can you recommend
me the simulation package which has a short and not-so-steep learning
curve ?

Your advice would be appreciated.

Regards,
Va1erian

If the bottle can be made of stainless steel, that is both non-magnetic

and

a fairly poor conductor, so you can use induction without too much

eddy-current

loss. You will have to design the coils and operating frequency to

minimize

such losses. Not something I can tell you how to do here. If you want
a more elaborate answer, I charge $250/hr for consulting.


--
Julian V. Noble
Professor Emeritus of Physics
jvn@spamfree.virginia.edu
^^^^^^^^
http://galileo.phys.virginia.edu/~jvn/

"Science knows only one commandment: contribute to science."
-- Bertolt Brecht, "Galileo".

If the bottle can be made of stainless steel, that is both non-magnetic
and
a fairly poor conductor, so you can use induction without too much
eddy-current
loss. You will have to design the coils and operating frequency to
minimize
such losses. Not something I can tell you how to do here. If you want
a more elaborate answer, I charge $250/hr for consulting.


--
Julian V. Noble
Professor Emeritus of Physics
jvn@spamfree.virginia.edu
^^^^^^^^
http://galileo.phys.virginia.edu/~jvn/

"Science knows only one commandment: contribute to science."
-- Bertolt Brecht, "Galileo".