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Message-ID: <3.0.5.32.20020403193914.00a077b0@pop3.esoterica.pt>
Date: Wed, 03 Apr 2002 19:39:14 +0100
To: rsgb_lf_group@blacksheep.org
From: "Brian Rogerson" <brian@esoterica.pt>
Subject: Re: LF: more loop inductance
In-reply-to: <3.0.1.16.20020403102400.30975ab6@pb623250.kuleuven.be>
References: <3.0.1.16.20020402140550.30cf29da@pb623250.kuleuven.be> <19519.020329@dx.ru>
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Hi Rik,

At 10:24 03/04/2002, you wrote:
>Having a closer look at the formulas for different loop shapes gives an
>indication that there is a correlation between the inductance of a loop and
>the ratio of perimeter^2/area.
>If this is correct it would allow to get a formula for rectangular loops :
>
>L = 0.4*(A+B)*(ln((A+B)/d)+7.6-0.35*(A+B)^2/(A*B))
>where L = loop inductance in uH, A = loop height in m, B = loop length in m
>and d = wire diameter in mm
>The formula would be valid for loops where B/A does not exceed 6.
>
>Does anyanoe have actualy measured the inductance of a big square loop ? 
>I would be interested to check the measured values against the calculated
>ones.

Have just measured my aluminium 6.4m * 6.4m * 45mm field strength
measuring loop and it gives 26.5uH.  I think the formula gives 25.3uH.
Each corner has two triangular reinforcing plates so the perimeter
will be a little shorter than 4*6.4m.

73, Brian
73 Brian     CT1DRP     IN51QD     41 09 58N  08 39 11W
http://homepage.esoterica.pt/~brian