On Jun 18, 4:47 pm, Moritz Winkler <moritz.wink...@[EMAIL PROTECTED]
>
wrote:
> I have question too. Is it possile with your software or formula to
> determin if there is an homogenous magnetic field left if i elevate the
> distance between to helmholtz coils. And if there is a field left how
> big it is an how strong the magnetic fiels is?
>
> The coils i use are 14 cm diameter helmholtz coils operated a max. 1,6 A
> an 65 V. They have each 755 turns. The normal distance is 7 cm between
> them. But at the experment i need a microscope an only can use them in a
> distance of 12 cm.
> Could you tell me if there is a homogenic magnetic field left an how
> strong, big it is?
> I don't have a clue how to calculate something like that because i'm not
> physicist, i'm a chemist.
> Perhaps you can give me a hint.
> many thanks from germany
> Moritz
No, my software is for a different purpose. Mine is to find the
electrical characteristics of air-core coils. You put in the wire and
the size of the core and winding depth and it comes up with
resistance, inductance, weight, heating, current for standard
temperature rise and the like.
I wish I could help you, but what you need is the Helmholtz coil
calculator which IS available somewhere on the internet. I've seen it
and used it, but I seem to have misplaced the URL. Maybe someone else
here remembers it.
The way it works is you plug in a certain size volume in which you
want a magnetic field of a certain size that is uniform to some given
percentage over that volume and the software barfs out the coils you
need. Generally speaking if you need a larger volume or a more uniform
field you need larger coils. Helmholtz coils do provide quite nice
uniformity over a reasonable amount of the space between them unless
you require extremely precise uniformity. If you need a high magnetic
field you may need to wind the coils with small diameter (insulated)
copper tubing and run water through it to dissipate the heat generated
by the high currents needed. If you need very high fields you'll need
a magnet setup with an iron core (NMR style technology). Super high
fields would require superconducting magnets.
The answer to your problem should be available with a decent internet
search.
Good Luck!
|
