Talk:Inductor

Just a layperson, trying to disambiguate coil -- should the currently non-existent induction coil be a separate article, or redirect here? or vice versa? Catherine 00:29 Apr 14, 2003 (UTC)

Why is "L" the symbol for inductance? - Joseph D. Rudmin

The "L" was chosen after Lenz's law. --Jeff Connelly 04:46, 30 November 2005 (UTC)[reply]

You mean the variable (The unit is usually Henrys.)? "I" was already taken for current; "i" for the square root of -1; not sure where L came from but I suppose it makes as much sense as anything. UninvitedCompany 19:49, 17 Feb 2004 (UTC)

Yes; how embarrassing! I know the difference between symbol and unit. I have corrected my question. - Joseph D. Rudmin

It's spelled characteristic.

Why did you move inductance to its own article? I think it is better in the inductor article with inductance as a redirect. They are essentially the same thing and should be in one article. Whether inductor or inductance I don't know, but the two belong together. That's like separating running from runner. An inductor (parasitic or otherwise), and nothing else, has inductance and inductance is a property of inductors. - Omegatron 16:58, Apr 13, 2004 (UTC)

At the very least, equations should be moved to inductance, and actual information on construction, etc. to inductor.

Why? They are both about the same thing. A "parasitic inductor" is still an inductor, right? And you don't construct those. Maybe there is no such thing, and there is only "parasitic inductance"? - Omegatron 19:32, Oct 18, 2004 (UTC)

I guess to a physicist, inductance is more important than an inductor, and to an EE, vice versa...? Pfalstad 14:59, 6 October 2005 (UTC)[reply]

Induction loop

I suspect that the new Induction loop article needs to be merged with another (this one?); it certianly needs a lot of work by someone who knows what they're doing. Mel Etitis (Μελ Ετητης) 13:12, 30 Mar 2005 (UTC)

No kidding; Is there much in that article that's salvagable?

And shouldn't it be about the gadgets used to tap phones and detect cars at traffic signals?

Atlant 13:29, 30 Mar 2005 (UTC)

Deletion of old history section

I had hopped to save some bandwidth but if I must: First, it is wrong. Stanley didn’t invent the first practical induction coil as stated. Inductions coils had been around for fifty years before that and Ruhmkorff was building excellent ones in 1850. What Stanley’s patent did cover was a version of an AC transformer that proved to be practical and similar to modern transformers. Since patents require titles and there was not yet a word for the device, he used whatever words were handy. The patent was titled “Induction Coil”. Mr. Stanley’s contribution is covered in transformer where it belongs. It has nothing to do with the Inductor article. This history section was left over here as a remnant of some confusion in terminology from a year ago. Let us recreate a history section only when we have something applicable to put into it. Meggar 05:58, 2005 Jun 8 (UTC)

Thank you for that explanation.

Atlant 11:47, 8 Jun 2005 (UTC)

practical issue

it seems that some inductors use coil that is NOT electrically insulated - i.e. blank. i'd like to understand why the current will not chose the shortest path (through adjacent loops of wire, which touch one another) rather than going through every loop and building up the magnetic fied.

secondly, would it not be most effective (in terms of maximum henries generated per volume of space occupied) to loop the wire in TWO countered sets of loops around the same core, which build opposing magnetic fields?

I think you'll find that what you see as bare wire is either separated by an air gap or a thin coat of paint. The voltage between turns is not that great so you don't need much insulation. Shorted turns is a common fault in motors, etc. Multiple layer inductors do exist, but I believe they are usually wound in the same direction to avoid some bad effects. More insulation is usually required between layers. --agr 13:29, 16 September 2005 (UTC)[reply]

Yes, winding wire as purchased is almost always insulated with a thin layer of varnish or enamel. Arnold is correct in that there are not usually many volts per turn, so a thin layer may provide enough voltage breakdown strength.

Regarding your second point, if alternate layers were wound in opposite directions, the magnetic flux would cancel out giving ZERO inductance. In fact, this is how some non inductive resistors are wound.--Light current 15:44, 16 September 2005 (UTC)[reply]

Category?

Why does Inductor belong to [[Category: Electromagnetic components]] while Capacitor belongs to [[Category: Electronics]]?--Astor Piazzolla 11:55, 14 December 2005 (UTC)[reply]

Typo?

Hi in the overview the word opposite appears -- do you mean opposes?

definition

In the equation for inductance you never say that L is inductance. If it's not, you need to say what it is.

Symbol added. Meggar 20:37, 19 December 2005 (UTC)[reply]

Inductance is the ratio of the back EMF induced to the rate of change of current.

Goddamn Wheeler and his inches

We should present the inductance equations in the SI form, foremost, since Henry is a SI unit and hell, this is a scientific article! These "easy equations for inches" created by some guy named Wheeler, apparently, are bastardized forms of the SI ones to make the use of inches easier and convenient. Yeah yeah, I know this is the English Wikipedia, so yadda yadda, but we need the SI equations in there, as they're the preferred and more scientific form.

The non-si equations could show up on a special section, even mentioning the Wheeler guy, describing how they were made up for convenience of imperial unit users, hence all the seemingly arbitrary constants. I'd do it myself, but alas, I don't have the equations, and that's also why I'm complaining. ☢ Ҡieff⌇↯ 21:37, 25 December 2005 (UTC)[reply]

"j is in ohms"

It says in the text "The impedance of an inductor (inductive reactance) is then given by:", then an expression, and then it's stated that "j is in ohms". Is this really true? Isn't j the imaginary unit, such that j^2 = -1, and isn't that unit always dimensionless? I think this is just a typo in the article, but I thought it best to seek consensus before editing, anyway. --Avl 08:24, 24 February 2006 (UTC)[reply]

Impedance can be a complex number. Take a look at the article for some more insight on that statement. ☢ Ҡi∊ff⌇↯ 08:46, 24 February 2006 (UTC)[reply]

But the imaginary number is not in ohms. It's a number. Does the article mean "j ohms"? — Omegatron 16:52, 24 February 2006 (UTC)[reply]

Hydraulic Model

Sureley, a transformer could be modelled hydralically by having a pair of differently-sized "turbines" hooked together mechanically - running on the same shaft. One could even connect the two tubine shafts with a slippery clutch to model transformer losses.

Pmurray bigpond.com 03:19, 25 May 2006 (UTC) Can an inductor affect another inductor in any way if their mutual inductance is 0?[reply]