From: Paul
Date: Sat, 16 Feb 2002 13:02:48 +0000
Subject: Re: [TSSP] Inductance of a flat spiral coil
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--
Paul Nicholson,
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Message-ID: <3C6E5776.4ECC2810@abelian.demon.co.uk>
Date: Sat, 16 Feb 2002 12:58:30 +0000
From: Paul
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To: John Tomacic
Subject: Re: Flat secondary measurements
References:
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John,
I copied those sums to the tssp list, so that the heavies on
there can tell us if it's wrong.
We assumed a 1.0 spacing ratio so far, ie a perfectly wound coil
with absolutely no gaps between the wires. I thought I'd see if
the optimum shape factors varied when you use practical spacing
ratios. I've altered the two input files to take account of the
spacing ratios.
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Paul Nicholson,
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filename="sharp-sr.in"
; Sample input file for acmi.
;
; Finding the solenoid form factor which gives highest L for a given
; piece of wire.
;
; See
; http://ourworld.compuserve.com/homepages/alansharp/mathpage.htm
;
; This input file demonstrates Alan Sharp's conclusion that the max L for a
; given piece of wire occurs when H/D is around 0.45
;
; First the fixed quantities
;
wirelen = 1400 * 12/39.37 ; A fixed 1400 feet (in metres)
wirediam = 0.001 ; A fixed 1 mm diameter wire
;
; And we'll vary the form factor and spacing ratio...
;
sr = [from 0.5 to 0.9 step 0.1] ; spacing ratio
formfac = [from 0.1 to 1 step 0.05] ; Our desired range of form factors
;
; And now the dependant quantities...
;
turns = sqrt( wirelen * formfac * sr/(wirediam * 3.14159))
height = turns * wirediam/sr
;
; Finally, the coil description.
;
coil {
radius height/formfac/2
height1 0
height2 height
conductor wirediam/2
turns turns
}
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; Sample input file for acmi.
;
; Finding the flat coil dimensions which gives highest L for a given
; piece of wire.
;
;
; First the fixed quantities (same as sharp.in)
;
wirelen = 1400 * 12/39.37 ; A fixed 1400 feet (in metres)
wirediam = 0.001 ; A fixed 1 mm diameter wire
;
; Defining a 'spiral factor' to be (outer_radius-inner_radius)/outer_radius...
; we vary this and the spacing ratio
;
sr = [from 0.5 to 0.9 step 0.1] ; spacing ratio
spirfac = [from 0.05 to 0.95 step 0.05] ; Our desired range of spiral factors
;
; And now the dependant quantities...
;
turns = sqrt( sr * wirelen/3.14159/wirediam/(2/spirfac - 1))
;
; Finally, the coil description.
;
coil {
radius1 turns * wirediam/(sr * spirfac) * (1-spirfac) ; Inner radius
radius2 turns * wirediam/(sr * spirfac) ; Outer radius
height 0
conductor wirediam/2
turns turns
}
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Maintainer Paul Nicholson, paul@abelian.demon.co.uk.