How to predict a magnet's field strength?

AI Thread Summary
To predict a magnet's field strength when creating a permanent magnet from ferrous material, key factors include the strength of the magnetic field it is exposed to and the duration of exposure. The material's properties, such as its Curie temperature, also play a crucial role; exceeding this temperature can cause the material to lose its magnetization. Utilizing an electromagnet, like a Helmholtz coil, can effectively magnetize the material when cooled below its Curie temperature. There are various formulas and rules of thumb available for estimating the resulting field strength, though specific calculations may depend on the material used. Understanding these principles is essential for successful magnet creation.
downtownjapan
Messages
6
Reaction score
0
Hi,

I am interested in making my own (weak) magnets exposing some ferrous metal to the magnetic field of an electromagnet, but this is theoretical rather than something I am able to actually do right now. I am wondering if there are any formulas that can help calculate/estimate the resulting field strength of the permanent magnet being created. I am guessing the key factors are the strength of the field the ferrous material is exposed to, and the time the material is exposed - but I am not sure how the material qualities might affect the process. Are there any formulas or even rules of thumb that I can use to estimate the permanent magnet's field strength?

Thanks,
Eddie
 
Physics news on Phys.org
Are you planning something like this guy does?

http://www.instructables.com/id/Permanent-Magnets/

If you heat a magnetic material above its "Curie temperature" it will lose any existing magnetization. So when it is in this condition you can expose it to a strong magnetic field (e.g., via an electromagnet such as a Helmholtz coil), and slowly lower the temperature.

See http://en.wikipedia.org/wiki/Curie_temperature
and http://en.wikipedia.org/wiki/Helmholtz_coil

You can make everything that you need.
 
I was using the Smith chart to determine the input impedance of a transmission line that has a reflection from the load. One can do this if one knows the characteristic impedance Zo, the degree of mismatch of the load ZL and the length of the transmission line in wavelengths. However, my question is: Consider the input impedance of a wave which appears back at the source after reflection from the load and has traveled for some fraction of a wavelength. The impedance of this wave as it...

Similar threads

Replies
7
Views
4K
Replies
198
Views
14K
Replies
2
Views
2K
Replies
2
Views
3K
Replies
43
Views
6K
Replies
42
Views
2K
Replies
14
Views
2K
Back
Top