Talk:Solenoid

Revert?

Does anyone else want a revert? A solenoid is a shape, so examples of solenoids, including those in physics and genetics I believe need to be all on this page, and can then be linked to their main article. I don't believe only adding a little blurb about solenoid disambiguation is appropriate here, especially when it isn't a true disambiguation, there is only one other option. Furthermore, Tomjc removed the link to solenoid in mathmatics. I am going to re-add the link to solenoid for mathmatics, and re-insert the information of solenoids in genetics and request the solenoids in genetics page he created be deleted. Any objections? Silver 19:28, 19 March 2007 (UTC)

As I have explained in the "talk". The term solenoid CAN refer to the shape of a solenoid or to the physical and tangible "solenoid" used in the physical sciences, ie.

Person 1 - Your drawing looks like a solenoid. Person 2 - It is solenoid in shape, but it does not conduct electricity. It is the model of current genetic explanation of how the histone complex can be further condensed into the solenoid shape. Another model is the "zigzag" model which I have not yet drawn.

This is the reason of disambiguation. A person searching the genetic "solenoid" model will be diverted to this page which has no relation to what the person is actually trying to find, HENCE the disambiguation page.

-tomjc

I don't think I understand what you are trying to accomplish. One, why did you remove the disambiguation for solenoid in mathmatics? Two, if the page is to be left as it is now, only regarding solenoids in physics, then there should NOT be a disambiguation page, where there is only one other option, the header should read, 'Se also solenoids in genetics and solenoids in mathematics' with both linked appropriately. I think my point is emphasized in that if a person is searching for a solenoid in genetics and they are brought to this page, it now has NOTHING to do with genetics at all. I think then solenoid should directly route to the disambiguation page, where I have readded the link to solenoids in math. Any 3rd party opinions? Silver 23:23, 19 March 2007 (UTC)

Hey again, so I've been linking, and prehaps the best way is the main route for solenoid should be a disambiguation page. We should seperate this article to solenoids in physics and solenoids in engineering, and for each to have it's own page in entirety. What do you think? Silver 23:31, 19 March 2007 (UTC)

Look, all I wanted to do was so that if someone were to search on wikipedia for "solenoid", they would go to the disambiguation page, and if they wanted to go to the biological sciences, mathematical, or engineering term for it, I thought it would make it easier. There is no malicious intent behind my edits, and if you really want it to go to the engineering term, so be it. I'm just saying that in the future it's going to evolve in that direction anyways. If I removed a link to the math term, it wasn't intentional. That is all.

Wow, I guess we had some miscommunication then, because I think that would be the best option as well. Currently searching solenoid leads to the physics page, but I think it should go to a disambiguation page as well. Also, I think we should seperate solenoids in physics and solenoids in engineering into two seperate pages, but my background is really only in genetics. BTW ty for adding more info about solenoids in genetics, I am just going to categorize and add a stub to it. Silver 13:55, 4 April 2007 (UTC)

Disambiguation

Some other person wrote - A solenoid is also a biological term. It's a coil of nucleosomes.

This is true, there needs to be information about solenoid in genetics. This page should be changed to first, a deffinition of a solenoid, as it is a shape. Then it's uses in electro-magnetism and where it is found in genetics. I don't think a disambiguation page should be used, as these are not truly seperate topics, solenoid is one shape, found in many places. Silver 04:02, 13 February 2007 (UTC)

I just found out that a solenoid is also "a space formed by the intersection of isobaric and isosteric surfaces." in Meterorology. www.factmonster.com. Since I know nothing on the subject, I won't add any material regarding this, maybe someone else with more knowledge can. Silver 04:05, 13 February 2007 (UTC)

Alternative definition:

A Solenoid is a form of electromagnet. In its simplest construction it consists of a number of turns of conductive wire through which a current is passed. This creates a magnetic field which is concentrated at the centre of the turns of wire. Any ferrous material that is brought into proximity is attracted by the magnetic field. Generally the construction is arranged so that the ferrous material is presented as a plunger within the coil which is free to move in and out and is held out by a spring when the current is switched off.

Much more efficient forms of a solenoid are made by wrapping the turns of wire around a ferrous C shaped core and where the moving ferrous core is T shaped, which when the current flows creates a tight magnetic loop (the T fitting into the C and touching at the lip and bottom)

"Much more efficient solenoids are made by winding the coil around a ferrous C-shaped core and using a T-shaped ferrous core. When a current flows, this structure creates a tight magnetic loop, the T fitting into the C and touching at the lip and bottom."

Can we get a more detailed description than this? I don't understand from this description. A link to a picture online would help. - Omegatron 13:21, Aug 2, 2004 (UTC)

I agree with the alternate definition, a solenoid does not need to have a metal core. It just makes it stronger. Fresheneesz 06:45, 6 February 2006 (UTC)

The definition should also include the usage of the term in chromatin in biology. A form of DNA packing which occurs during interphase. A solenoid in that case is a small packaged coil of chromatin. —Preceding unsigned comment added by 74.218.108.82 (talk) 19:15, 26 September 2008 (UTC)

Request:

Under each type of solenoid, I would like to see a list of what they are used for and how they accomplish their work (just stating they can move a metal slug doesn't tell me much). From the description given, they *sound* useless, but of course they're used throughout industry, vehicles, etc. I would also like to see references to Fleming's Left Hand Grip Rule and/or Fleming's Right Hand Grip Rule.

Could some one PLEASE clearly explain, how much force in Newton a solenoid exerts on the armature in terms of;

a) Voltage (V) b) Current (Amps) c) Number of Turns d) Air gap (metres) e) diameter of the Coil(metres)

What effect does wire diameter have? What effect does the geometry of the armature have? What effect does the geometry of the core have?

Thank you

thecoolsundar —Preceding unsigned comment added by Thecoolsundar (talk • contribs) 12:24, 14 August 2010 (UTC)

Question about induction

Why is "electromagnetic induction" used as the description of the source of the magnetic field? Induction is the production of potential due to flux... it is not the explanation of the creation of the magnetic field.

I agree. I deleted tha bit. --Heron 16:27, 28 October 2005 (UTC)

An Example of a Solenoid

How about an electric hoist? I wrote a manual for one once. Imagine your "T" as the metal rope and your "C" as the spooling core. Once powered electrically, the magnetism pulls the rope around the core- through one lip, into its own seating/grooves (to prevent tangle/damage- and into the other lip/attached to a heavy object, as if winding thread around a spool, or a vacuum cord around its housing. Imagine, also, the natural reverse/"unwinding" that would occur if you turned the electric off without putting a break on first!... Don't ships use them, to pull objects to themselves and themselves into docks?

Electromagnet

Hello. Isn't a solenoid the same thing as an electromagnet?

Not exactly. Electromagnets come in all shapes, not just solenoidal. --Heron 17:19, 10 August 2006 (UTC)

Also, the uses can be different. In common parlance, electromagnet implies an electromechanical use; whereas, solenoids often implies use as an inductor (aka 'choke') e.g. in circuits.--ElectronicsEnthusiast 22:30, 19 July 2007 (UTC)

Shih Shin Technology

Is the following section needed since it doesn't direct the user to anything whithin Wikepdea. IMHO it is a pointless header?

This article is about the coil of wire. For Shih-Shin Technology Co., Ltd.(www.shihhsin.com.tw), see Manufacture and Supply Solenoid (mathematics).

Additional: Have requested page be given semi-protection due to repeated spam from the above. --Rehnn83 15:04, 10 August 2006 (UTC)

Picture discrepancy

the picture displayed on the Solenoid article says that it's a bunch of solenoids. The picture displayed on the Electromagnet article is the exact same but says it's a bunch of electromagnets.

Removed "Solenoids in Fiction"

This section doesn't add anything to the topic, so I've deleted the movie trivia. —Preceding unsigned comment added by 67.170.224.208 (talk) 06:43, 27 October 2006

Shouldn't this have been disucssed on here first. P.S. Please sign your comments --Rehnn83 08:05, 27 October 2006 (UTC)

I've removed it again. This section was so incredibly puerile and incompetent, it was embarrassing to see it in an encyclopedia. —Quicksilver^{T @} 00:02, 12 June 2007 (UTC)

It may not be the best place to have it but it does warrant inclusion. It is one of those "Cool Sounding" words that Science fiction has effectively hijacked. (E.g. Bessel Equations in Star Trek, Flux Capacitor in Back to the Future). Three of the four links point directly to the Wikipedia Aritcle/section where the term solenoid is used. Feel free to suggest a more appropiate place or wording. -- Rehnn83 ^Talk 08:27, 12 June 2007 (UTC)

Derivation of magnetic field inside/outside solenoid?

Is the derivation of the field inside and outside worth including? If so, I'm happy to write it up.

I think it would be a useful addition to the article --Rehnn83 20:46, 29 October 2006 (UTC)

absolutely yes--ElectronicsEnthusiast 22:23, 19 July 2007 (UTC)

clean up

for example, a solenoid does not have to be wrapped around an object, it is not only the physics community that uses the term solenoid - in fact, they are in the minority compared to electrical engineers, &c. --ElectronicsEnthusiast 22:23, 19 July 2007 (UTC)

The derivation section is in need of some clean up regarding accuracy. for example the field outside the solenoid is zero. You could say that the field goes to zero as the distance from the solenoid approaches infinity, but the magnetic field outside the solenoid is crtainly not zero. Also, it does not give the field as a function of x,y,z (or, in cylindrical coordinates), so it's really not a derivation of the field around the solenoid. btw: he differential element is r x j / |r|³, where r x j is the cross product of the vector r and j, r is the vector position of an arbitrary point in space (maybe a different letter than r would be appropriate as r would come up for radius), and j is an infinitessimal current. |r| is the magnetude of the vector r (pythagoran)./

Yes i was just thinking that

how about changing " A solenoid is a 3-dimensional shape where a coil is wrapped around a central object."

to someth9ing like

"A is solenoid is a 3-dimensional coil." obviously this sentence above needs to be improved but at least its accurate.

The problem with that definition is is that a 3-dimensional coil can be called just that, a coil, or a helix. This concept and this page are still horribly misleading and inaccurate. If a solenoid is a shape, which appears in biological and physical constructs and is also a piece of technology that does not have anything in common with the 3-D shape then there needs to be a disambiguation page.

Furthermore, currently the second sentence begins "In physics, the term solenoid refers to a loop of wire, often wrapped around a metallic core..." but the first sentence already stated that "A solenoid is a three-dimensional coil." The beginning of the second sentence is redundant and superfluous. The disambiguation page should have a heading called Shape where the definition can be stated and under the heading will be links to all sources that use the term solenoid in reference to the shape, like Genetics. The separate headings along the lines of 'Physics' and/or 'Engineering' and 'Math' can be plan to see. Silver (talk) 08:53, 30 September 2008 (UTC)

World's most powerful solenoid magnet.

The world's largest solenoid magnet is a superconducting magnet used in the CMS experiment at CERN, the European Organization for Nuclear Research. It is 12 meters in diameter, 12 meters long and develops a field of 4 Tesla with a stored energy of 2600 Mega Joules (enough to melt 18 tonnes of gold!) See http://public.web.cern.ch/Public/en/LHC/CMS-en.html —Preceding unsigned comment added by 134.158.138.183 (talk) 12:27, 14 January 2008 (UTC)

etymology

Does anybody know sth about the etymology of the word, is it latin? --Saippuakauppias ⇄ 00:14, 7 November 2008 (UTC)

Readability for non-experts

I just looked up this page to help my daughter with her grade XII physics. It didn't help me, I'm afraid. The writing is too technical and simple concepts that should be relevant are missing. For example, if discussing magnetic fields, shouldn't 'North' and 'South' be referred to? The diagrams are not very helpful, which is I think the main limitation. The second diagram (cross-section view) has no labels and means nothing to somebody who needs a diagram! The third diagram is much too clumsy. It lacks an indication of North. There are no magnetic field lines. The cylinder is so crude that it is possible to see it in the wrong 3D perspective. A good schematic showing what is shown in the historical diagram from a patent would be more helpful.DonaldSHouston (talk) 04:11, 18 December 2008 (UTC)

Incorrect formula

The field inside an infinitely long solenoid does not contain the h term as this page does. In fact there is no case where a finite length solenoid would contain the term is such a simplistic manner. In other words the formula is only tidy when we consider infinitely long solenoids for a good approximation. See http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html —Preceding unsigned comment added by 80.123.59.201 (talk) 12:40, 5 February 2010 (UTC)

Honda automatic transmission

I heard somewhere Honda uses automatic transmissions which are essentially solenoid-driven manual units, and this avoids the band wear and torque converter waste of a planetary gear automatic transmission. Is this something that can be added to the main page? MWS (talk) 15:20, 1 July 2010 (UTC)