Talk:Alternator

It seems to me that an alternator, as described on this page, is just a local definition for an electrical generator. Steam turbine generators are called "turbogenerators" in North America. Additionally, Gas turbine generators are also called turbogenerators. Alternator is an archaic term in North America for this kind of industrial machine. The "alternator" term is reserved for car and truck electrical generators. —Preceding unsigned comment added by 12.48.74.181 (talk) 02:46, 25 February 2010 (UTC)Reply

http://en.wikipedia.org/w/index.php?title=Alternator&oldid=211659249

Here is the culprit that did it.

(cur | prev) 00:37, 14 May 2008 Wtshymanski (talk | contribs) (17,030 bytes) (copyedit - why are we talking about motors here? two phase can be symmetrical, too - link.) (undo) (cur | prev) 14:01, 11 May 2008 TubularWorld (talk | contribs) (17,805 bytes) (Undid revision 211659222 by 76.226.25.243 (talk)) (undo)

--Ericg33 (talk) 03:51, 17 June 2011 (UTC)Reply

Articles are supposed to be about their topics. This article is about alternators, not motors. We don't need the table of speeds twice. It's very confustion to talk about a rotating magnetic field produced by three-phase stator windings in the contest of an alternator, that description is more usefully given when talking about motors. --Wtshymanski (talk) 15:19, 17 June 2011 (UTC)Reply

I notice that the issue has arisen on this page several times since 2006. I propose that this article be rewritten into two pages: automotive alternator and AC electric generator with appropriate cross-links. When both articles are in good shape, alternator can become a disambiguation page. I'm willing to work on this if others think it's a good idea. M Carling 08:20, 16 September 2012 (UTC)Reply

• Support, although I'd keep the names as Alternator (automotive) and Alternator (AC generator). Andy Dingley (talk) 09:22, 16 September 2012 (UTC)Reply

I'm neutral on the names. Either your or my suggested names are fine with me. M Carling 15:19, 16 September 2012 (UTC)Reply

This article has been tagged for merging. Any thoughts? Andy Dingley (talk) 09:57, 24 October 2012 (UTC)Reply

Maybe not a merge, but perhaps refactor any content that talks about AC machines in general and then specialize this to automotive alternators. It would be very rare to find a machine described as an "alternator" that wasn't used in a vehicle; larger machines are nearly always called "generator", so we have "standby generator set", "diesel generator", "turbine/generator unit", and so on. Automotive alternators are quite enough for a free-standing article by themselves. --Wtshymanski (talk) 13:53, 24 October 2012 (UTC)Reply

Although 'generator' is more common now, back in the war of the currents the two terms dynamo and alternator were widely used, as appropriate, and generator was rare. Andy Dingley (talk) 16:55, 24 October 2012 (UTC)Reply

Well, yes, but we don't get a lot of users telegraphing from 1890. --Wtshymanski (talk) 18:04, 24 October 2012 (UTC)Reply

We have a perfectly good article title at electrical generator to cover whatever one might wish to say about generation. Alternator and dynamo are clearly distinct, identifiable topics with clear scope that is separate from each other. Why should they be merged, and (given that anything we want to say about generation can be said there already), effectively deleted? Andy Dingley (talk) 23:53, 24 October 2012 (UTC)Reply

I agree. --Chetvorno^TALK 12:24, 5 October 2013 (UTC)Reply

Permanent magnet synchronous generator contains a paragraph or two that would be useful here - that article has no references or links and rather than fix it in place, perhaps it should be redirected and merged. --Wtshymanski (talk) 16:13, 10 December 2012 (UTC)Reply

Just as long as you don't merge it and redirect it and half do the job as you usually do. 86.145.244.183 (talk) —Preceding undated comment added 17:36, 10 December 2012 (UTC)Reply

• oppose merge Keep it or delete it. It's either independently notable, or it isn't. Merging an article, because the current article is as yet weak, and that reason alone is a poor reason to merge. Andy Dingley (talk) 17:59, 10 December 2012 (UTC)Reply
• Comment. Could that article be moved to its own section in Electric generator?--Canoe1967 (talk) 21:59, 22 December 2012 (UTC)Reply

• Redirect: If I understand it correctly, the permanent magnet synchronous generator is just another Magneto (generator). So, we just redirect that page to Magneto (generator),right? If we change it to a redirect. The last paragraph of Permanent magnet synchronous generator seems to contain interesting information. The rest before the last paragraph are generic information about alternator so we can just discard. If we decide to copy that last paragraph, maybe we should put it under the "Magnetos for power generation" section to elaborate on the disadvantages of using permanent magnet. However, the last sentence of that paragraph can be discarded. Any thoughts? Z22 (talk) 04:37, 6 October 2013 (UTC)Reply

You will not find a better multimedia effect on wikipedia. If you can then tell me. Below is the edit that removed it.

(cur | prev) 14:17, 12 December 2012‎ Wtshymanski (talk | contribs)‎ . . (21,196 bytes) (-3,490)‎ . . (linearity not required and this whole discussion is beside the point for alternators anyway) (undo)

REVERT IT!--Ericg33 (talk) 03:00, 27 May 2013 (UTC)Reply

This section seems quite extensive to me, enough to merit its own article. While archiving this talk page, I had a quick glance and noticed some debate over this, but I didn't spot any definitive votes over what should be done (as I said, it was a quick glance, so I apologise if I overlooked such a vote). For this reason I'm inviting a vote below on whether this section should create its own article and how.

• Split as a new article named 'Automotive alternators'. — Sasuke Sarutobi (talk) 21:16, 29 August 2013 (UTC)Reply

• As previously, split but as Alternator (automotive) and Alternator (AC generator). Andy Dingley (talk) 23:58, 29 August 2013 (UTC)Reply

• A split is reasonable. I think Andy's Alternator (automotive) is a better target, as these devices are usually just called alternators by most folk, with the (automobile) suffix as the standard WP way of disambiguating similar subjects. --Mark viking (talk) 16:01, 30 August 2013 (UTC)Reply

The diagram in the Principal of Operation section looks really great and it makes easier for readers to follow. However, I'm not sure if it is based on a reliable source somewhere. All sources I have searched point out to another design where the poles are in rotation similarly to this design, but they use two coils, one on the top, the other on the bottom instead of this rectangular armature loop. The two coils are wired serially but having the winding in the opposite direction between the two coils. An example of what I'm talking about is here. My feeling is that the design shown in the diagram in this article would work also, but I couldn't find a reference for it. I hope it is not WP:OR. If anyone know any sources that mention about this simple design, please share. Thanks. Z22 (talk) 17:35, 6 September 2013 (UTC)Reply

Yes, it's complete crap (it's a motor not an alternator). However whenever it's removed, it gets re-added. Andy Dingley (talk) 17:44, 6 September 2013 (UTC)Reply

Why is there a long section in this article about multiphase ac motors? It has nothing to do with alternators and seems completely out of place. If there's meant to be some relevance perhaps it could be made somewhat more explicit. 84.93.97.179 (talk) 16:46, 10 September 2013 (UTC)Reply

I would like to propose reorganization of this article a bit to help readers in the navigation. No information is removed (brushless alternators is moved to the right sub-section). Also I would like to add some more info on classification of alternators from a public domain document. I put a draft version of my proposed change in User:Z22/sandbox/draft. Here is the diff [1]. If there is no objection, I will populate the change to this article. Feel free to suggest further changes or edit directly to that sandbox page. When we are comfortable, I will copy the final to the article page. I will put a proper attribution for those contributors. Thanks. Z22 (talk) 00:27, 10 December 2013 (UTC)Reply

Since there is no objection to the proposed change, I am populating the change from the draft space to the article. Further improvements can be done directly to the article. Z22 (talk) 05:17, 21 December 2013 (UTC)Reply

I've worked out the wiring of an historic 750 Kw poly-phase poly-dipole Rotating Armature Alternator, part of Folsom Powerhouse State Historic Park.
Please see my article for creation "Rotating Armature Alternator" under my username space Douglas Nelson Turner. I've read your following line--

"The revolving armature type is found only in alternators of low power rating and generally is not used."

Still, since my machine is now only an historic interest and relatively low power, would you consider placing a note in your history section, that my 750 Kilowatt alternator may be the most powerful rotating armature poly-phase poly-dipole example, or refer to the main article Folsom Powerhouse State Historic Park in your "see also"?

Thanks, Doug.. Douglas Nelson Turner (talk) 17:18, 23 April 2014 (UTC)Reply

Wiring details of one machine are probably too specialized for this article ( and may be too specialized for a general purpose encyclopedia); if you've "worked it out", the problems with WP:OR arise, too. When the first machines went into the Niagara Falls generating station, they were the most powerful in the world at the time (much larger than 750 kVA) and had rotating armatures - however, designers quickly realized this was the hard way to do it. --Wtshymanski (talk) 18:19, 23 April 2014 (UTC)Reply

Please don't put wiring details in this article.

These Niagara machines started service August 26th 1895, one month after the Folsom machines started in 13 July 1895.

The frequency of the Niagara Falls output was only 25hz. 25hz lost the War of Currents. Folsom was the first to transmit the winner 60hz.

The Niagara Falls alternator had only two phases.

Two phase wiring is simple, compared to 3-phase. Folsom was the first to send three phase high power.

The power transmitted by Niagara was less than Folsom's

Folsom was the first, 13 July 1895, to send 60hz, three phase, high power(2010hp - two alternators) long distance. Niagara transmitted only 1000 to Buffalo.

The Niagara machine's field rotated around the armature!

Niagara falls beat us months later on distance, but was still not the wining frequency of 60hz. They were down at 25hz, and not at the better inherent three phases.

The Folsom machines had record power at distance, while using modern phasing and frequency. They helped 60hz win the war of frequencies. The Folsom Machines were the apex revolving armatures and thus deserve note. --Douglas Nelson Turner (talk) 00:59, 21 May 2014 (UTC)Reply

I half-rememberd there was something weird about the original Niagara machines and got it wrong - rotating but external field, fixed armature. I don't think the difference in frequency was all that important, nor phasing - once you have a polyphase machine, you can make any set of phases you want ( and Niagara's old machines were connected to a Scott transformer bank for transmission anyway). Is there something notable in the Wikipedia sense about the Folsom machines that we need to talk about them in this article? --Wtshymanski (talk) 19:21, 21 May 2014 (UTC)Reply

Why aren't you complaining about the lack of Wikipedia sense the Folsom Powerhouse State Historic Park article has? If you think the Folsom powerhouse has Wikipedia merit, you should give its alternators some mention. Its alternators are the heart of the park. It's alternators are the reason the park is a National Landmark!

Folsom held the world record for a while and beat Niagara Falls to the punch.

As I said "The Niagara machine's field rotated around the armature! ". The 25hz frequency was doomed as fatally flawed. Scott transformers reflect an unbalance to the source, when the two phase loads are not balanced. It is impossible to correct for this shortcoming.

This machine was huge for it's time. It has record power as 3phase revolving armature. It is the apex of it's type. If the "Folsom Park" is of note in Wikipedia, then it's record holding alternator should merit note in Wikipedia. This article has a sub-section called "By rotating part". One small historic footnote referencing the Folsom machines, before the sentence "The revolving armature type is not often used." would not hurt. --Douglas Nelson Turner (talk) 05:43, 22 May 2014 (UTC)Reply

These armatures, at Folsom, have no coils!

Elihu Thomson, in these converted DC machines, took 18 phases down ::::to six then to three. He mitigated the inherent off balanced ::::weight in an elegant way. The counterclockwise helixes ::::that weave back and forth around the rotors are the most ::::complicated ingenious forms of winding, I've seen. Have you ::::come across any winding this clever?--Douglas Nelson Turner (talk) 08:56, 22 May 2014 (UTC)Reply

No, they've got coils. If you were an ant crawling along the copper bar from one load slip ring to the next, yuo'd completely circumnavigate iron in the rotor. Gotta have coils...--Wtshymanski (talk) 17:56, 22 May 2014 (UTC)Reply

This article has long had a section on applications with a sub section for Radio alternators. They're not an important means of transmitting radio, but they are an unusual and significant application for alternators, indicating an upper frequency limit and requiring novel construction techniques.

This section is now being repeatedly deleted, despite opposition, by that regular merger and hatchetman of articles, Wtshymanski. Anyone have any thoughts as to whether this section should stay? Andy Dingley (talk) 02:51, 7 May 2014 (UTC)Reply

I'd forgotten the Wikipedia policy that anything in an article for 6 weeks is revealed truth and can no longer be revised. Some articles need editing with a hatchet. --Wtshymanski (talk) 03:04, 7 May 2014 (UTC)Reply

And your point is? Andy Dingley (talk) 03:18, 7 May 2014 (UTC)Reply

can a 2002 pathfinder alternator work on a 1997 pathfinder — Preceding unsigned comment added by 192.235.51.141 (talk) 22:31, 2 September 2014 (UTC)Reply

I don't see the point of mentioning Tesla's alternator in the History section. It was not the first high frequency alternator - Elihu Thomson invented the high frequency oscillator in 1889.[2], [3], [4], [5] If we're going to mention radio alternators, it should be either Thomson's or the most notable: the Fessenden or Alexanderson alternators. --Chetvorno^TALK 03:32, 19 April 2015 (UTC)Reply

Good point. Its another one of those "Tesla did something" statements you find Tesla fans have sprinkled throughout Wikipedia (I noted a similar statement at Radar[6]). Usually referencing RS on the topic (instead of books on Tesla) cleans up whether Tesla had any significant roll. Fountains of Bryn Mawr (talk) 15:14, 19 April 2015 (UTC)Reply

Presently the 'Synchronous speeds' section states:

One cycle of alternating current is produced each time a pair of field poles passes over a point on the stationary winding. The relation between speed and frequency is N = 120 f / P {\displaystyle N=120f/P} N=120f/P, where f {\displaystyle f} f is the frequency in Hz (cycles per second). P {\displaystyle P} P is the number of poles (2,4,6...) and N {\displaystyle N} N is the rotational speed in revolutions per minute (RPM).

I'm not sure that this statement is correct. My understanding is that one 360 degree rotation of a rotor pole pair generates one cycle in a stator coil. I suspect that the factor of 2 relates to the ripple after full wave rectification (full wave rectification doubles the frequency).

Also the title, 'Synchronous speeds' is meaningless and does not relate to the contents of the section.

I also suggest that the frequency of the field wave form should be the subject of the formula:

Fs = (N * RPM)/60

Where: Fs is the frequency of the stator coil signal in Hz. N = the number of rotor pole pairs. RPM = the rotor speed in revolutions per minute.

This formula is simpler and easier to follow.

CPES (talk) 13:10, 28 October 2016 (UTC)Reply

I love a shotgun. Hear a rustling in the bush? Blast away - maybe some pellets hit a target. What could possibly go wrong? And it makes you feel so *powerful* - a real boost to the ego.

But if we are tagging WP articles, we should identify particular claims that need stiffening up with a little blue footnote. If anyone has read the references already cited in this article, they'd have a pretty good idea of what alternators do. A stale shotgun tag at the top of the article isn't helping here. Not every paragraph needs a reference, if there's a comprehensive set of references listed in the article. --Wtshymanski (talk) 18:12, 10 November 2018 (UTC)Reply

@Wtshymanski: Shotgun referencing (to hijack your allusion), is equally unacceptable as it does not identify what claim is being sourced from which reference. Each claim requires a reference to a reliable and verifiable source and must be identified with 'a little blue footnote', as you so elegantly put it. For a large reference, like a book, the little blue footnote also requires a page reference to make it easy for others to verify the claim (something that is required by the CS2 referencing style). I grant that tags at the top of articles are rarely acted upon, but they should be followed up.

After tagging an article with such a tag, it should be left for a reasonable period of time (possibly a month to three months depending on article size), after which every unreferenced claim (that is: every claim not accompanied by a 'little blue reference') can be deleted as unreferenced. Any editor wishing to restore the claim(s) must provide the appropriate referencing (I.A.W. WP:BURDEN). TheVicarsCat (talk) 17:18, 29 November 2018 (UTC)Reply

We don't need to tag every sentence with a little blue number. --Wtshymanski (talk) 18:54, 30 November 2018 (UTC)Reply

Every separate claim (not necessarily every sentence) requires a reference (and a 'little blue number') identifying the reference supporting it. Anything that is not supported by an identifying reference can be feely removed by anybody. In case you had not noticed: Wikipedia is, generally, not a reliable source of information on anything. That's why the supporting references are important. TheVicarsCat (talk) 11:53, 1 December 2018 (UTC)Reply

Which claims do you see that need referencing? --Wtshymanski (talk) 19:08, 3 December 2018 (UTC)Reply

Easy one. Every claim that does not currently have a reference (i.e virtually the whole article).

What constitutes, in your opinion, a claim that needs a reference? Are we allowed two sentences in a row that rely on the same reference? --Wtshymanski (talk) 00:56, 12 December 2018 (UTC)Reply

Try not to be ridiculous. Of course you are allowed two sentences in a row that rely on the same reference provided, of course, that they are on the same subject. If you have two sentences that make different claims that rely on the same reference then that is what the <ref name="whatever" [ref]>{{rp|[page]}} construct is for (or use CS2 with "|page=[page]} as required. But I suspect that you know all of this already and are just being awkward. TheVicarsCat (talk) 14:02, 12 December 2018 (UTC)Reply

The unsourced material has now ben removed (apologies if I missed anything). Anyone restoring it, must provide a proper in-line reference covering any material so restored in accordance with the requirements of WP:BURDEN (or a 'little blue number' as Wtshymanski likes to describe them as though they are somehow deprecated). No reference, and it will be deleted again. I shall similarly treat any other article from which you have deleted a 'shotgun tag' in due course. TheVicarsCat (talk) 17:55, 19 December 2018 (UTC)Reply

The practical energy conversion efficiency of alternators neds to be mentioned, perhaps with a comparison against d.c. generators. EEye (talk) 11:11, 22 October 2019 (UTC)Reply

Dependant on size, bigger more efficient, single, polyphase, frequency or DC. Therefore no one figure. A commonly used value in the rail industry for large diesel/electrical loco gens is 94%.Suckindiesel (talk) 19:51, 22 October 2019 (UTC)Reply

Support. The article mentions cooling but does not explain why cooling is needed. Efficiency is part of that answer. The article could be enriched by explaining where the heat comes from. Maybe electrical resistance in the coils? Voltage drop in the rectifier? Mechanical friction? Frame dragging? (JK) Something else? 208.82.100.219 (talk) 14:45, 12 November 2024 (UTC)Reply

Why does the caption for the first photo mention the Russian empire? To my knowledge Budapest was part of the Austro-Hungarian Empire in 1909.Wikigreenwood (talk) 22:50, 29 July 2020 (UTC)Reply

upon a re-read I think I understand what the caption is trying to say, will edit for clarity. Wikigreenwood (talk) 22:51, 29 July 2020 (UTC)Reply