Talk:Saturation (magnetic)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
WikiProject Physics (Rated Start-class, Mid-importance)
WikiProject icon This article is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
 

Redirects[edit]

—DIV (128.250.80.15 (talk) 01:44, 20 May 2008 (UTC))

Why have these redirects been removed? It took me ages to realise that there actually was an article on saturation magnetisation on Wikipedia, because I didn't think it would be named like this. --Freedo50 (talk) 21:38, 26 August 2009 (UTC)

Permeability[edit]

In chapter "Introduction" the following sentence should be changed:

"The relation between the magnetizing field H and the magnetic field B can also be expressed as the magnetic permeability: μ = B / H. The permeability of ferromagnetic materials is not constant, but depends on H. In saturable materials the permeability increases with H to a maximum, then as it approaches saturation inverts and decreases toward zero.[2]"

Of course the permeability decreases towards one, (even though it requires infinite field strength to go there)... 21:16, 17 October 2011 (UTC) // Jan — Preceding unsigned comment added by Ssfja (talkcontribs)

I wrote that. You're right, of course. If it was just ferromagnetism, the magnetization would approach a maximum, but because of the paramagnetic response of the unpaired electrons, the magnetization keeps increasing with the H field. Thanks for the correction. --ChetvornoTALK 02:36, 18 October 2011 (UTC)
That business about reaching a maximum is probably referring to the susceptibility. The permeability just increases monotonically. I have corrected that, as well as the limiting value. RockMagnetist (talk) 02:57, 18 October 2011 (UTC)
No. The permeability is the slope (B/H) of the line from the origin to a point on the magnetization (hysteresis) curve. At low H fields the curve curves upward, so permeability increases. It reaches a max near the knee of the magnetization curve. In saturation the curve becomes almost flat and B is almost constant, so increasing H causes B/H to decrease. (Bakshi, fig. 3-37) --ChetvornoTALK 05:52, 18 October 2011 (UTC)
Fair enough. I'm not used to this particular usage. However, the limit should still be μ0 in SI units. Bozorth probably uses Gaussian. RockMagnetist (talk) 06:25, 18 October 2011 (UTC)

Magnetization curves of 9 ferromagnetic materials, showing saturation.[edit]

That graph -- are the materials in the correct order? Sheet steel saturating at 1.6, Cobalt around 0.4? I would think the red line is the best material, and the gray line the worst? Drmemory (talk) 17:16, 7 May 2012 (UTC)

I checked the source here (see also the table on pp 88-89 and note that the numbering in Fig. 42 is not the same). Perhaps the real problem is that this source is so old - published in 1917! RockMagnetist (talk) 17:40, 7 May 2012 (UTC)

Saturation Current[edit]

I searched for "Saturation current", and got a story about diodes. The I think the saturation section here needs expanded or else a separate article on "Saturation current (magnetic)". I also propose that "Saturation current" be changed to "Saturation current (diode)" and a disambiguation added pointing to both.

I will leave a similar note on "Saturation current" talk. Comments? :- ) Don 15:17, 9 May 2012 (UTC)

I'm not familiar with a magnetic interpretation of Saturation current. Can you point me to a reference? RockMagnetist (talk) 15:40, 9 May 2012 (UTC)
Me neither. --ChetvornoTALK 16:01, 9 May 2012 (UTC)
Sorry, talk page slipped past me, and you can never find a good example when you want one. Dealing with transformers and inductors, it is important to know the saturation current, because if you exceed it, they stop behaving nicely. I was looking for a way to calculate it, or how it is calculated by manufacturers. Here is a Bourns data sheet with Isat listed as parameter: [1] :- ) Don 03:13, 17 July 2012 (UTC)
Cool! Now Wiki, how do I calculate or determine the saturation current when not given? :- ) Don 02:10, 18 July 2012 (UTC)
Not so hard if you have the right equipment: [2] :- ) Don 02:31, 18 July 2012 (UTC)