Wire Inductance.

[lord loh.]

I thought I would post this question seperately...

Does the inductance of a wire (at high frequencies) depend on the wire material and thickness?


Again, Thanks in advance

 

[Optikon]

I thought I would post this question seperately...

Does the inductance of a wire (at high frequencies) depend on the wire material and thickness?


Again, Thanks in advance

Yes, other parasitic properties start becoming more pronounced and eventually dominate the impedance.

 

[lord loh.]

So how is it related?

Thinner the wire, less the parasitic inductance?

 

[mstechca]

the thinner the wire, the greater the inductance.

Inductors and resistors are calculated the same way.

parallel resistors equal smaller resistance while resistors in series equal large resistance.

wire has resistance (maybe 1 micro ohm). If we made it thicker, then we have basically wrapped a whole bunch of wire together and therefore, the resistance is smaller. (1 microohm in parallel with 1 microohm < 1 microohm).

 

[Styx]

Think of inductance as flux linkage.
IF you have a piece of wire with current flowing through it, then any flux that can re-inforce other flux will increase inductance.

Now with higher frequency you get this thing called skin effect.
With DC all of the conductor is used to carry the current. When it is AC, not all the conductor is capable to carry current.

ie for a cylender of wire, current flows in a donut pattern (when viewed cross sectionally).

This can mess with reactances.

Think of the eqaution of an inductor

V = L di/dt

R = Lw

increase freqency increase the "resistance".

 

[lord loh.]

Think of inductance as flux linkage.

Flus can be linked with the current. So more current will mean more flux. So greater the wire diameter, and more conductive the material, more flux and hence more inductance ????

ie for a cylender of wire, current flows in a donut pattern (when viewed cross sectionally).

Why is this? Due to repulsion of electrons and attempt to reach the surface of the conducting material and top leave it?

 

[Roff]

Here's a calculator.
I don't know if it's right - it's just something I found on the Internet.

 

[stevez]

Several pages of various editions of ARRL Handbooks address this subject nicely.

 

[Nigel Goodwin]

Several pages of various editions of ARRL Handbooks address this subject nicely.

You could use the same reply on almost all threads in these forums! :lol:

 

[Styx]

Several pages of various editions of ARRL Handbooks address this subject nicely.

You could use the same reply on almost all threads in these forums! :lol:

Except you would lack smart arse comments like this


in reply to the

Why is this? Due to repulsion of electrons and attempt to reach the surface of the conducting material and top leave it?

When talking abt skin effect: It is to do with current density and Maxwell equations - it is extrealy heavy going but lots of proof to show this is hte case with increase frequecy - it is one of those things you have to be either insane to follow the workings or just accept as gospel.

Having tried the first (Well forced to) at Uni, I would recommnd just accept

 

[stevez]

I agree. We could probably have a list of canned responses to handle many of the questions. I find myself repeating the same stuff though I doubt it's to the same person.

I do have the 2005 ARRL Handbook on CD and it's relatively easy to copy/paste - that's how I'd like to respond at times. Unfortunately it would violate copyright laws so I don't do it.

Back to the canned responses - I'd be willing to contribute if someone wanted to organised some Frequently Asked Questions or a list of common topics.

 

[Nigel Goodwin]

I do have the 2005 ARRL Handbook on CD

Didn't know you could get it on CD?, I've got a very old paper copy somewhere 8)

But I do think EVERYONE should have a copy of either the ARRL or RSGB handbooks (and preferably both!), they are SO useful, and not just for radio amateurs!.

 

[stevez]

I have Paul Scherz' "Practical Electronics for Inventors". It does cover the basics but I'd say it's not for beginners. He addresses many of the details. An example - there's a handful of pages on FETs explaining the basics and the not so basics is clear terms. That's one I'd love to cut/paste from but I only have the paper version.

ARRL Handbook softcover version comes with the CD now. I prefer the book to the CD for doing research but it's hard to beat the cut/paste when trying to keep notes or describe something to someone in an email.

 

[lord loh.]

But I do think EVERYONE should have a copy of either the ARRL or RSGB handbooks (and preferably both!), they are SO useful, and not just for radio amateurs!.

What are "ARRL or RSGB handbooks" can I get them any where(India Specifically)?

Please gentlemen, believe me, I am posting about this topic on this forum after reading all the books that I possess.

 

[Nigel Goodwin]

What are "ARRL or RSGB handbooks" can I get them any where(India Specifically)?

"American Radio Relay League"

and

"Radio Society of Great Britain"

They are the two national amateur radio associations in those two countries, both produce excellent books - their 'Handbooks' in particular are well worth having, even if you're not a radio amateur.

I presume you could get them off the Internet?, a quick search on amazon.com finds the ARRL handbook, although the 2005 issue is listed as out of print. I can't seem to find the RSGB one on a quick search?, but there's quite a nice 'cookbook' at https://www.amazon.co.uk/gp/reader/0750652144/ref=sib_dp_pt/202-1152773-1955061#reader-link which looks quite interesting?.