From: "Christopher R. Carlen"
Subject: Re: Deriving H for magnetic cores
Date: Wed, 18 Dec 2002 17:44:23 -0800
Organization: Sandia National Laboratories, Albuquerque, NM USA
References: <3DFF8FA6.4593A00A@mmm.com.DELETETHIS> <3DFFE9DB.1BEFBBE3@earthlink.net> <3E008AB8.141E41D5@mmm.com.DELETETHIS> <3E00BB56.FD61ED55@mmm.com.DELETETHIS>
NNTP-Posting-Date: Thu, 19 Dec 2002 00:43:11 +0000 (UTC)
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Roy McCammon wrote:
> "Christopher R. Carlen" wrote:
>>Roy McCammon wrote:
>>[nicely worded discourse snipped]
>>>2. A contour such that | H | = constant. You probably
>>> mean it in this sense. That seems plausible, (requiring
>>> only continuity?), but that sense doesn't pertain to the
>>> discussion because in the special case we needed the
>>> fact that H . dL = constant on the contour of interest.
>>>3. A contour such that H . dL = constant
>>Wouldn't it be actually true that the "contour of constant H" in which
>>we are interested is the one in which H=|H_vec| is constant (your #2),
>>since then you could take H (scalar magnitude) out of the integral,
>>which is the necessary mathematical step to make use of Ampere's Law.
> No, that is not sufficient. You need the component of
> H that is tangential to the contour to be constant. If
> that is so, then the integral of H . dL becomes a constant
> times L.
If H=|H_vec| is constant over the path (so you could pull it out of the
integral), then if you could carry out the integration, wouldn't you get
H as a function of the relevant spatial variables? Or even if you
couldn't carry out the integral but numerically, you still have defined
a function that is H(x,y,z) or whatever coordinate system.
Not that this would be particularly useful, since the direction of H is
not described by this function.
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA