skin effect of a solid copper wire

[DUG]

Solid round copper wire maximum useable frequency
______________________________Skin____Ohms per
GA____DIA____CM____MUF (Hz)__Depth(in.) 1000'
1___0.2905 __84396____320____0.1453__0.126
2___0.2586 __66867____403____0.1293__0.158
3___0.2302 __52979____509____0.1151__0.200
4___0.2049 __41975____643____0.1024__0.253
5___0.1824 __33257____811____0.0912__0.318
6___0.1623 __26349___1,024___0.0812__0.402
7___0.1445 __20876___1,292___0.0722__0.506
8___0.1286 __16540___1,631___0.0643__0.639
9___0.1145 __13105___2,058___0.0572__0.805
10__0.1019 __10383___2,598___0.0509__1.00
11__0.0908 __8240.1___3,274___0.0454__1.26
12__0.0808 __6524.8___4,134___0.0404__1.58
13__0.0720 __5185.9___5,202___0.0360__2.00
14__0.0641 __4115.1___6,555___0.0321__2.53
15__0.0571 __3257.2___8,282___0.0285__3.18
16__0.0509 __2590.0__10,415___0.0254__4.02
17__0.0453 __2049.8__13,160___0.0226__5.06
18__0.0403 __1626.7__16,583___0.0202__6.39
19__0.0360 __1292.4 __20,872___0.0180__8.05
20__0.0320 __1025.2 __26,313___0.0160__10.1
21__0.0285 __814.29 __33,128___0.0143__12.8
22__0.0254 __644.66 __41,845___0.0127__16.2
23__0.0226 __509.92__ 52,901___0.0113__20.3
24__0.0201 __404.41 __66,704___0.01005__25.7
25__0.0179 __319.08 __84,540___0.00893__32.4
26__0.0160 __254.50 _105,994___0.00798__41.0

example: For those who wish to run solid house wire at #14 AWG, you will start not to use the cente of your wire at 6,555 Hz. (equivalent wire diameter will decrease above this frequency)

Solid wire used for audio inductors (crossovers, etc) may want to use a solid core for more resistance (smaller equivalent wire) at higher frequencies for a lower Q

Switching power supplies should use multi-stranded wire to use 100% of wire diameter at their operating frequencies

Etc.

 

[Doug]

Skin effect

DUG;

I have heard of skin effect but never really worried about it unless I was transmitting RF energy through the conductor. An interresting subject that I would like to learn more about.

What does the terms " CM " and " MUF " stand for?

Thank's, Doug

 

[DUG]

CM is circular mils... the square of the wire diameter in mils (0.001") this number is useful in calculating current carrying ratings of wire.

MUF is maximum useable frequency at which point electrons do not use the centre part of the wire as a conduction path.

Most people don't realize how significant it really is.

 

[Steve Eddy]

Most people don't realize how significant it really is.

Significant in what respect exactly?

se

 

[Steve Eddy]

MUF is maximum useable frequency at which point electrons do not use the centre part of the wire as a conduction path.

I just looked at the chart again and no, that's not what it means.

The MUF is based on the skin depth at that frequency being half the diameter of the wire. One skin depth is defined as that point at which the current density at the center of the conductor is 37% of that at the surface. The center of the conductor is still being used for conduction.

se

 

[DUG]

I did not know that

It may not quite be as significant as I had thought.

I still like ground planes and stranded wire

 

[Steve Eddy]

I did not know that

It may not quite be as significant as I had thought.

I still like ground planes and stranded wire

You'll get there faster in an airplane and your wire should seriously consider signing up for some sort of roadside assistance program.

se

 

[Sch3mat1c]

No, because his plane is riding in ground effect - much less induced drag than off the ground.

Tim

 

[Fred Dieckmann]

Just plane fun

You'll get there faster in an airplane and your wire should seriously consider signing up for some sort of roadside assistance program.

se

That was so creative that I missed it the first time through. And people think I have a strange sense of humor. Good one Steve!
Speaking of wired, I have an idea...........

He'll fly his astral plane,
Takes you trips around the bay,
Brings you back the same day,
Timothy Leary.
Timothy Leary.

He'll take you up, he'll bring you down,
He'll plant your feet back firmly on the ground.
He flies so high, he swoops so low,
He knows exactly which way he's gonna go.
Timothy Leary.
Timothy Leary.

The Moody Blues - Legend Of A Mind_