Re: transferring electrical energy through metal wall

I aready told you how.

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

Jim Klein


[EMAIL PROTECTED] ([EMAIL PROTECTED]) 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