73 
MB, S. BUTTERWOKTH ON EDDY-CURRENT LOSSES 
If there are n wires each of length l, the total loss due to the proximity of the wires 
will therefore be 
Aviators*,*; 
or if the wires are connected in series to give a total direct current resistance R = R 0 wZ, 
the added resistance due to the proximity of the wires is 
in which 
= W»R G (z) 
1 n 
u n = 
n i 
(51) 
(52) 
and depends only on the geometry of the axes of the wires. 
The total resistance (apart from capacity effects) is got by adding the skin effect to 
(52) so that the formula for the alternating current resistance R' of the parallel wire 
system is 
R' = It jH- F (z) + u n ~ G (s)|.(53) 
This formula may also be applied to circular coils if the winding section is small in 
comparison with the radius. It remains to determine the values of u n . 
(11) Single Layer Systems .—If all the axes lie in one plane (fig. 6), then, numbering the 
wires 1, 2, 3. s .... n from left to right, 
1 
1 
h s — -h —— + • • • + 
s s+1 n—s 
From this formula the following values of A;/ are calculated :— 
s ' 
n = 4 
n — 8 
n = 16 
n = 24 
1 
3 • 35 
6-70 
11-00 
14-00 
2 
0-25 
' 2-10 
5-06 
7-30 
3 
0-25 
0-61 
2-82 
4-63' 
4 
3-35 
0-06 
1-61 
3-1.4 
5 
0-06 
0-89 
2-16 
G 
0-61 
0-42 
1-49 
7 
2-10 
0-14 
0-98 
8' 
6-70 
0-02 
0-62 
9 
&c. 
0-36 
10 
0-18 
11 
0-06 
12 
0-01 
