DIRECT CURRENT DYNAMOS AND MOTORS. 
53 
lines per square inch, for sheet thicknesses of .010, .020, 
and .040 inch. 
TABLE 20. 
EDDY CURRENT FACTORS FOR DIFFERENT FLUX DENSITIES 
AND THICKNESSES OF LAMINATION. 
B, 
Density, 
Lines pr. 
\sq. inch. 
Eddy Current Factor, «. 
Watts per cubic inch. 
Thickness of Lamination: 
.010” 
0207” 
.040” 
sq. Inch 
B, 
Density. 
Eddy Current Factor, «. 
Watts per cubic inch. 
Lines pr. 
Thickness of Lamination: 
.010” 
.020” 
.040” 
| 10000 
20000 
30000 
40000 
45000 
47500 
50000 
52500 
55000 
57500 
60000 
62500 
65000 
67500 
70000 
72500 
75000 
7'7500 
80000 
82500 
.0000004 
.000002 
.000004 
.000007 
.00U009 
.000010 
.000011 
.000012 
.000013 
.000014 
. 000015 
.000017 
.000018 
.000019 
.000021 
.000022 
.000024 
.000025 
.000027 
.000029 
.000002 
.000007 
.000015 
.000027 
.000034 
.000038 
.000042 
000046 
.000051 
.000056 
- 000060 
.000066 
.000071 
.000076 
.000082 
.000088 
.000094 
.000101 
.000107 
.000114 
.000007 
.000027 
.000060 
000107 
.000136 
-000152 
.000167 
.000185 
.000203 
-000222 
.000241 
.000262 
"000282 
.000305 
.000328 
.000352 
.000376 
.000402 
.000428 
.000456 
8501'0 
87500 
90000 
92500 
95000 
97500 
100000 
192500 
105000 
107500 
110000 
112500 
1150: 0 
117500 
120000 
125000 
130000 
135000 
140000 
145000 
.000030 
.060032 
.000034 
.000036 
000038 
.000040 
.000042 
.000044 
.000046 
000049 
.0C0051 
.000053 
.000055 
.000058 
.000060 
.000066 
.000071 
.000076 
.000082 
.000088 
.900121 
.000128 
.000136 
.000143 
.000151 
.0U0159 
.000167 
.000176 
.000184 
.000194 
.000203 
.00.0212 
.000221 
.000231 
.000241 
.000262 
.000283 
.000305 
.000328 
.000351 
000483 
.000513 
.000542 
.000573 
.000t03 
.000636 
.000703 
.000737 
.000774 
.000810 
.000848 
.OCC885 
.000925 
.000964 
.001046 
.001130 
-001218 
.001311 
.001405 
000669 
46. 
Specific Power Loss in Armature.— 
Having com- 
puted the power losses in the armature, their sum divided 
into the cooling surface gives the actual specific cooling 
surface of the ca gsm ease which, as stated in Par. 16, 
should be between . 
5 and 
.75 square inch per watt for a 
drum armature, and between .75 and 7,0 square inch per 
eS 
watt for a ring armature: 
S, 
Wy, + Wy + w.” 
