From: "Mark S. Rzeszotarski, Ph.D."
Date: Thu, 07 Sep 2000 05:49:59 -0500
Subject: Re: [TSSP] Low Q Values
--=====================_968341799==_
Content-Type: text/plain; charset="us-ascii"
Hello All:
I have attached an ASCII file which looks at the contributions of
skin effect and proximity effect to the effective resistance of a coil,
using Malcolm's excellent data from a few years ago. I did the calcs back
in 1996, but I think they are correct. For your perusal and interpretation.
Regards,
--=====================_968341799==_
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: attachment; filename="m.dat"
Closewound Coil Data
Reff = total AC resistance = Rskin + Rprox
Rskin = skin effect resistance
Rdc = DC resistance of wire
No Added Top Terminal Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 190.0 351.0 195.4 52.4 143.0 49.5 3.95
4.00 224.0 393.0 163.3 43.6 119.7 39.6 4.12
3.00 276.0 389.0 148.0 36.5 111.5 29.7 4.98
2.00 367.0 353.0 135.5 31.5 104.1 19.8 6.85
1.00 600.0 285.0 119.0 25.9 93.1 9.9 12.03
.56 890.0 182.0 123.5 22.6 101.0 5.5 22.28
0.7 Inch Height 9 Inch Sphere Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 159.0 300.0 191.3 51.5 139.8 49.5 3.86
4.00 184.0 347.0 151.9 42.7 109.2 39.6 3.84
3.00 221.0 356.0 129.5 34.7 94.8 29.7 4.36
2.00 284.0 326.0 113.6 28.4 85.2 19.8 5.74
1.00 438.0 267.0 92.8 22.6 70.1 9.9 9.37
.56 644.0 220.0 73.9 19.4 54.5 5.5 13.34
7 Inch Height 9 Inch Sphere Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 149.0 317.0 169.7 51.3 118.4 49.5 3.43
4.00 172.0 318.0 155.0 42.4 112.6 39.6 3.91
3.00 205.0 341.0 125.4 34.1 91.3 29.7 4.22
2.00 262.0 339.0 100.8 27.5 73.2 19.8 5.09
1.00 401.0 299.0 75.8 21.8 54.1 9.9 7.66
.56 587.0 243.0 61.0 18.6 42.4 5.5 11.01
0.7 Inch Height 4.5 x 19.5 Inch Toroid Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 179.0 299.0 216.1 52.1 164.0 49.5 4.37
4.00 152.0 292.0 149.1 41.9 107.2 39.6 3.77
3.00 178.0 301.0 123.4 33.1 90.3 29.7 4.15
2.00 222.0 288.0 100.5 25.8 74.7 19.8 5.08
1.00 330.0 233.0 80.1 20.0 60.1 9.9 8.09
.56 476.0 208.0 57.8 17.0 40.8 5.5 10.43
7.0 Inch Height 4.5 x 19.5 Inch Toroid Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 128.0 290.0 159.3 50.6 108.7 49.5 3.22
4.00 146.0 316.0 132.4 41.8 90.6 39.6 3.34
3.00 171.0 323.0 110.4 32.8 77.6 29.7 3.72
2.00 216.0 322.0 87.5 25.6 61.9 19.8 4.42
1.00 327.0 261.0 70.8 20.0 50.9 9.9 7.16
.56 477.0 227.0 53.1 17.0 36.1 5.5 9.57
17.3 Inch Height 4.5 x 19.5 Inch Toroid Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 121.0 269.0 162.4 50.5 111.9 49.5 3.28
4.00 138.0 286.0 138.2 41.5 96.7 39.6 3.49
3.00 163.0 291.0 116.8 32.6 84.3 29.7 3.93
2.00 207.0 283.0 95.4 25.2 70.2 19.8 4.82
1.00 316.0 256.0 69.8 19.7 50.1 9.9 7.05
.56 465.0 226.0 52.0 16.8 35.2 5.5 9.37
Spacewound Coil Data
Reff = total AC resistance = Rskin + Rprox
Rskin = skin effect resistance
Rdc = DC resistance of wire
No Added Top Terminal Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 186.0 286.0 231.3 177.4 53.9 176.3 1.31
4.00 220.0 329.0 190.7 142.7 48.1 141.0 1.35
3.00 274.0 351.0 162.3 108.2 54.2 105.8 1.53
2.00 371.0 399.0 120.9 77.0 43.9 70.5 1.71
1.00 605.0 451.0 76.3 54.3 22.0 35.3 2.16
.56 899.0 392.0 60.5 45.7 14.9 19.7 3.07
0.7 Inch Height 9 Inch Sphere Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 169.0 232.0 259.1 177.1 81.9 176.3 1.47
4.00 205.0 233.0 251.0 142.5 108.5 141.0 1.78
3.00 216.0 292.0 153.8 107.5 46.4 105.8 1.45
2.00 280.0 325.0 112.1 74.9 37.2 70.5 1.59
1.00 433.0 336.0 73.3 47.7 25.6 35.3 2.08
.56 632.0 353.0 47.2 39.3 8.0 19.7 2.39
7 Inch Height 9 Inch Sphere Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 145.0 227.0 227.2 176.8 50.3 176.3 1.29
4.00 168.0 258.0 185.7 142.1 43.6 141.0 1.32
3.00 201.0 275.0 152.0 107.4 44.7 105.8 1.44
2.00 259.0 307.0 109.7 74.3 35.4 70.5 1.56
1.00 397.0 325.0 69.5 46.1 23.4 35.3 1.97
.56 577.0 326.0 46.7 37.8 8.9 19.7 2.37
0.7 Inch Height 4.5 x 19.5 Inch Toroid Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 176.0 234.0 267.5 177.2 90.3 176.3 1.52
4.00 149.0 225.0 188.9 141.9 47.0 141.0 1.34
3.00 174.0 232.0 156.0 107.1 48.9 105.8 1.47
2.00 219.0 237.0 120.2 73.2 47.0 70.5 1.70
1.00 326.0 237.0 78.2 43.3 35.0 35.3 2.22
.56 467.0 253.0 48.7 34.6 14.1 19.7 2.47
7.0 Inch Height 4.5 x 19.5 Inch Toroid Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 125.0 204.0 217.9 176.5 41.4 176.3 1.24
4.00 142.0 225.0 180.0 141.8 38.2 141.0 1.28
3.00 168.0 243.0 143.8 107.0 36.7 105.8 1.36
2.00 213.0 266.0 104.1 73.0 31.1 70.5 1.48
1.00 323.0 271.0 67.8 43.2 24.6 35.3 1.92
.56 467.0 279.0 44.2 34.6 9.5 19.7 2.24
17.3 Inch Height 4.5 x 19.5 Inch Toroid Case
H/D F(kHz) Q Reff Rskin Rprox Rdc Reff/Rdc
5.00 118.0 178.0 235.8 176.4 59.3 176.3 1.34
4.00 135.0 204.0 188.8 141.7 47.1 141.0 1.34
3.00 160.0 231.0 144.1 107.0 37.1 105.8 1.36
2.00 204.0 239.0 111.0 72.8 38.2 70.5 1.57
1.00 312.0 256.0 69.3 42.8 26.5 35.3 1.97
.56 456.0 274.0 43.9 34.3 9.6 19.7 2.22
--=====================_968341799==_
Content-Type: text/plain; charset="us-ascii"
Mark S. Rzeszotarski, Ph.D., MetroHealth Medical Center,Radiology
Department, Cleveland OH 44109-1998
--=====================_968341799==_--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.