Talk:Multiway switching/Archive 1

California 3-way
Surely this is same as illustrated earlier in para 2.1 Two locations, method 2? Suckindiesel (talk) 21:01, 14 September 2009 (UTC)
 * Yes, it is...though I wish the illustrations showed it better. I may do a pencil sketch and post it here on the talk page so someone with the skills can turn it into a good illustration. It would be good to show how the "California" setup lets you have lights at both ends of a hall, or an indoor pilot light to remind you the garage lights are on. This was the point of combining all the stubs together. --Wtshymanski (talk) 21:44, 14 September 2009 (UTC)
 * Yes, I thought they looked the same. Therefore, "California" para could be combined with para 2.1. At present, they 're treated as if completely different designs. Suckindiesel (talk) 22:22, 15 September 2009 (UTC)

Illustrations
I've used the same symbols and style as the tables to explain the California 3-way and Carter connections. However, I have not yet found a Web site or entry at archive.org that explains the names for these two systems. while the blog and forum posts are suggestive, it would be a good thing to have a more reliable reference source. --Wtshymanski (talk) 03:36, 20 June 2010 (UTC)

symmetric networks
There is a whole design technique that telephone companies evolved that they called symmetric networks, of which this multiway switch circuit is just the simplest case, which corresponds to a parity calculation. A common circuit implemented with this technique was the two-out-of-five circuit, that is it efficiently produced an output signal if, and only if, any two out of a group of five relays were actuated. For instance, this was used as a check circuit on decimal digit registers; there are 10 ways to have two out of five relays operated. It seems worth preserving this knowledge. I will try to come back with a reference. --AJim (talk) 04:05, 23 June 2011 (UTC)
 * This article is kind of hung up on light bulbs, though. Some kind of pointer to the fact that the study of swtiches in combinations has deeper significance than the hall light is probably worth while, but I wouldn't put a "two out of five" circuit in this article since it seems unlikely to be used in the context of lights. We don't have a switching  circuit theory overview article forest, but as usual we've got lots of articles about partciular leaves.  --Wtshymanski (talk) 13:46, 23 June 2011 (UTC)
 * Well, after checking, we didn't sem to have Switching circuit theory but we do now. It needs expansion and references...--Wtshymanski (talk) 14:52, 23 June 2011 (UTC)
 * OK, I added further reading citations to two books that can be used as authorities on symmetric networks. I agree that this article is light bulb-oriented, and I think you agree that more can and should be said about the general theory. Once there is a general description of the circuits it can be linked to from here. (Relays are peculiar too because operated and unoperated states are distinguished, not just two positions of a switch, so that, for instance, there are similar topologies for both operated, both unoperated, and only one operated switch networks.) --AJim (talk) 18:29, 23 June 2011 (UTC)

Very heated image discussion
I would like to discuss possible labels and choices for background colour. I would like to leave the neutrals as white. They may show better if I had a black border to them. Any thoughts?--Canoe1967 (talk) 23:52, 8 May 2012 (UTC)
 * Hmm, normally we make backgrounds transparent. Does it really add a lot to the article, is it worth your time and effort? We've got some pretty explicit block diagrams now, our proverbial bright 12-year-old reader can figure out the terminals on her particular switch and match them to the diagram. We don't want or need to make this a "how-to" guide, there's plenty of those out there. Plus if we make it too exact a representation, some schoolboy or Colonel Blimp from East Cheem will tag it with "globalize" if he can't buy the switches at his local Tesco. --Wtshymanski (talk) 21:45, 9 May 2012 (UTC)

Who invented this technique?
I can't find any historical information on this practice. Anyone have any resources in that regard? —Preceding unsigned comment added by 99.236.252.249 (talk) 06:57, 23 May 2011 (UTC)
 * Before doing any research, I would say that early electricians requested manufacture of a SPDT switch first. They probably brought it up at a convention/workshop/trade show type thing. I can see how the switching would be useful when the first houses were being wired in the 1800's. I wouldn't doubt that Edison lab monkeys made the first three way and the four way soon after.--Canoe1967 (talk) 12:34, 8 May 2012 (UTC)

I found one old multi-pole switch that was patented for telegragh lines in 1882.
 * http://www.google.com/patents?id=0I5XAAAAEBAJ&printsec=frontcover&dq=253080&hl=en&sa=X&ei=gIHCT8CENMmViAKu97mMAQ&ved=0CEIQ6AEwBA --Canoe1967 (talk) 19:38, 27 May 2012 (UTC)

Representing circuits as images – voltage or current?
Ignoring for a moment the aspect of animation, which is the clearest means by which to show the "live" circuit? Should the wires with live voltage on them be highlighted? Or those with current flowing through them?

As a "functional" illustration, the current flow shows the parts of the circuit that are active in making it work. As a "safety" warning, the voltage shows those that are live. Which is more useful to an encyclopedia? Andy Dingley (talk) 23:11, 21 May 2015 (UTC)
 * To be pedantic the second picture is not showing the voltage. There is a voltage drop across the bulb and the return from the bulb is connected to neutral which is at a different voltage. --Salix alba (talk): 12:13, 22 May 2015 (UTC)
 * This is an encyclopedia. The best method of representing a complex switching system is to illustrate which way the current flows.  That way a  person uneducated in the complexities of multi-way switching can follow which way the current flows through the switches.  It is less useful to illustrate the neutral wire as having voltage on it when it has not, though in the diagrams presented, it is really showing current flow, because it becomes black when the lamp is out even though it is still connected to the neutral of the supply.  My only concern is that following a voltage convention would make the Carter system harder for an uninitiate to follow whereas the current flow scheme achieves this.  DieSwartzPunkt (talk) 16:29, 22 May 2015 (UTC)

Language problem
I understand how "staircase switches" work. I even wired some up myself once. But I am British, and find the article almost impossible to understand. I do not know what "pole", "throw", and "shell" mean. I did figure that "hot" must mean what we Brits call "live" (and was surprised to see "live" used instead of "hot" in the second paragraph of the "Carter system" section). "Traveler" probably means "rocker".

I don't know the best way to deal with this. Maybe a glossary somewhere in the article for the use of British readers? Maproom (talk) 07:08, 23 May 2015 (UTC)
 * As a Brit, it's just impossible to understand the sheer horror that is US domestic wiring. You can't translate concepts like "arc fault interrupter" because we don't either have or need the things, we fix the underlying problem instead. Usenet and rec.woodworking used to have a really good FAQ on workshop wiring. Terrifying, the stuff the US gets up to!
 * If it's to be internationalised, do it section by section, not trying to inline translated words onto national topics. Andy Dingley (talk) 09:36, 23 May 2015 (UTC)
 * If British multiple switch wiring is radically different, perhaps there ought to be a new subsection explaining the differences, or possibly even a separate article. As things stand now, it is not at all clear how the British ring circuit system works for multiple switches.
 * A glossary article translating American and British (and Indian and Aussie?) electrical terminology would be quite useful. Reify-tech (talk) 11:24, 23 May 2015 (UTC)
 * Topologically and electrically, the "traveller" system (as named here) is the universal one for British wiring and has been since WWII. However that's only part of the story: there's also the question of cable layout. There are a couple of ways this has been done and that did change over the years. Partly this was to make it easier to install (more fittings, less labour) with the "loop in" system. Electrically there have also been changes in how many wires were run in the cable. There weren't always earth wires provided in lighting cables. It's also usual these days to cable with twin live cables, either three (2L+E) or four core (2L+N+E) rather than stock three core (L+N+E) cable. Coverage should also include the problem of "borrowed neutrals" (saving cable by sharing neutrals between floors on different circuits - makes it hard to isolate them).
 * None of this has anything to do with ring mains, as they're for power circuits, not lighting. Andy Dingley (talk) 11:50, 23 May 2015 (UTC)
 * Thanks for the explanations; much of this was never clear to me before. The term "loop in" is still unclear, and Wikipedia search doesn't find anything helpful. It does sound like there ought to be some kind of article explaining the features and terminology of British electrical wiring. Reify-tech (talk) 13:05, 23 May 2015 (UTC)
 * Loop-in wiring deserves an article, but as it's UK-specific it'll probably get deleted as NOTHOWTO.
 * It's the 1960s realisation that using more, more complicated, parts could provide an overall cost saving by reducing the increasingly expensive labour. It rode on the back of the change to double-insulated multi-core cables. Rather than the previous ad hoc designs of using the fewest individual wires between the fewest junction boxes (all cabled in indistinguishable single-core black 7/.029), the plan was to run a single multi-core cable between each of the ceiling roses. These roses then went to a loop-in style where instead of two screw terminals they'd have four (adding both earth and switched came in at much the same time - three way boxes are rare in lighting sizes). The drop from the rose to the wall switch was then one single cable. This was much less cable to pull (even if more cores) and it didn't involve junction boxes hiding in unexpected places. It also fitted with '70s+ trends for redecorating and seeing lightswitch placement as flexible to suit decor, rather than rigidly installed and set forever. UK construction being based on plastered brick rather than US cardboard, it had previously been seen as major work to move electrics around and so was rarely done: the telephone (singular) was kept in the draughty entrance hall, each room had one light switch by one door and radiators went under the windows out of the way. We've got better since. Andy Dingley (talk) 13:28, 23 May 2015 (UTC)

The development of technology around the globe has always mystified observers from other territories. Electrical standards and wiring standards developed, more or less, completely independently around the world, which is why there was a proliferation of different voltages, frequencies, plug designs and wiring standards. That each standard was often the product of some committee or other, it is not surprising that in many cases the result was the equivalent of a camel when the committee was trying to design a horse. In some cases, the standards were dictated by a parent nation such as with the British Empire where most members went down similar routes. Television standards started out the same way but as communication between countries improved, the standards converged on two fundamental systems. Today, newer technology develops in a fairly standard manner across the globe, though there is the occasional pocket of resistance.

Electrical wiring standards do still vary considerably from country to country with each country wondering why other countries do things the way they do. A good case in point is the British ring circuit system. Almost every other country is mystified why we do it. But in reality it provides a saving in material (particularly the expensive copper) over other systems. It is often stated that it was the post-wartime shortage of copper that gave rise to the system, but there is no evidence that this was the driving criterion, but the saving in copper was a beneficial side effect. – Live Rail    &lt; Talk &gt;  12:07, 25 May 2015 (UTC)

RfC: stationary SVG diagrams or animated GIF diagrams
Are the various diagrams of multi-way switching better represented by stationary SVG diagrams or animated GIF diagrams?  KDS 4444 Talk  13:42, 17 May 2015 (UTC)
 * SVGs are the preferred diagram format for Wikipedia articles, though sometimes GIF files are also used, especially when a GIF image can convey information which an SVG alone cannot. We have on Commons GIF animations of the process of multi-way switching (e.g., File:Carter_System.gif et al.) which demonstrate the flow of electricity in a way that the present SVG images in this article cannot do, or must do with multiple images side-by-side.  Some editors have complained that the GIF images are distracting and that they cannot be printed and are therefore unsuitable.  Please add your comments below.  Thank you.   KDS 4444  Talk  13:49, 17 May 2015 (UTC)
 * The foregoing comment sounds reasonable to me. If some people find GIFs distracting, too bad; other people find them helpful where they are appropriate, and in an encyclopaedia claims for information should logically take precedence over complaints based on personal preferences. WP cannot constructively exclude functionally useful standard formats that are effectively universally supported, such as GIFs, JPGs, etc as long as they are constructively used according to usual WP standards. For example a GIF showing how cute a dog looks when wagging its tail should certainly be excluded, but GIFs showing the development of a Bezier curve, or the orbit of an astronomical body, or the rotation of a 3D view of a molecule, or any of thousands of dynamic processes are not merely permissible, but praiseworthy. The fact that they are not always printable is sad of course, but neither are video clips, and it would be totally unrealistic to outlaw everything that cannot be printed because it is animated or otherwise challenging for printers. JonRichfield (talk) 06:46, 18 May 2015 (UTC)
 * The .gif images convey no information that is not adequately represented by the .svg images. There is therefore no valid reason to change them for an unpreferred format.  KDS4444 has claimed several times in his deletion requests that the .svg images are inacurate in order to have them deleted so that we are forced to use his .gif images.  I have examined both sets of images and the .svg images are correct in every particular - this is not surprising because the author of those images is an established electrical engineer.  DieSwartzPunkt (talk) 16:23, 18 May 2015 (UTC)
 * The deletion of the SVG images is not at issue here. I have already indicated that I am utterly indifferent to their continued existence, even with their errors (having been created by an electrical engineer does not mean they cannot contain errors, and they do).  I am not interested in forcing my images down anyone's throat, you have not read my reasoning on the deletion proposal page and your insistence that I am acting here in anything less than good faith is insulting. If you need me to point out the technical inaccuracies of the SVG images, you should contact me directly through my talk page and I will be more than happy to do so.  Thanks.  KDS 4444  Talk  10:28, 21 May 2015 (UTC)
 * For someone who is "utterly indifferent" to them, why did you nominate both for deletion? You also keep claiming that they are "technically inaccurate", yet no-one else can see what the problem is and you still haven't said what's wrong with them. Andy Dingley (talk) 10:56, 21 May 2015 (UTC)
 * I nominated them [both] for deletion as an act of housekeeping. I already made this clear on the deletion nomination page.  Why do you need me to reiterate that here?  And so let me explain one of the errors in the SVG files: the SVG of the California 3-way switch does not contain a red line all the way from the word "hot" to where the letter "B" is located.  This is a hot wire all the way along, even though power is not flowing through it.  The diagrams directly above it in the current article also show hot lines which are red and which dead-end with no power flowing through them.  This is what I mean by an error.  Please correct me if I am not interpreting the images correctly.  Also, since the GIF files I generated are different in ways like this from the SVG files, you can interpret any difference between the SVGs and the GIFs as evidence of my effort at corrections.  Word-by-word explanations are tedious when the animated images I created already do this.  If you need further examples of what I mean by "errors", please see those GIF files and compare them to the SVG images, yes?  My corrections are all there for the viewing, though they are no more significant than this (but an error is an error).  Thanks.   KDS 4444  Talk  11:12, 21 May 2015 (UTC)
 * Thanks for explaining what the issue is – see below. Andy Dingley (talk) 23:03, 21 May 2015 (UTC)
 * I think it's a question of interpretation. If the red lines are indicating which wires are 'hot' then, yes the diagram does not continue it to the terminal identified as B.  The problem here is that the ground wires are also red but are not 'hot'.  However, my interpretation is that the red wires only identify which way the current flows, in which case the diagrams are correct with no wrongly coloured wires.  DieSwartzPunkt (talk) 16:20, 22 May 2015 (UTC)


 * The animated gif images are very distracting, and harder to trace in detail and fully understand than the stationary images. At most, their existence could be mentioned in the "See also" section, for readers more interested in dazzle than in understanding. Reify-tech (talk) 17:07, 18 May 2015 (UTC)
 * You see? And I feel the exact opposite: the stationary SVG images showed no "switching", whereas the GIF images do.  The latter do not contain any unnecessary "pizazz" or flash, they contain only the same basic information, except they show it happening rather than as a series of stills which the viewer must then parse individually.  Look at them again...  These GIF images work exactly the way that the switches they represent work, just as fast, just as immediate.  I could slow them down, but I do not think that would increase their understandability or their accuracy, yes?  KDS 4444  Talk  10:28, 21 May 2015 (UTC)
 * Two side by side images would work fine without the distraction element. One particular feature of the images I don't like is the fact that the wires run through the switches. I think it would be a little clearer is the wires were routed so they ran round the side of the switch blocks. I am really not a fan of animated gifs. They are distracting which makes it harder to focus on the content and hence lowers the encyclopaedic value. You also can not control the speed. I like to study the individual frames in a diagram, trace the path of the electrons and ponder why its necessary for the electrons to go up and done the three wires three times. There is another problem with this particular gif, is that one frame is ofset by a few pixels making the switch bodies and text jump back and forward between the two frames. --Salix alba (talk): 05:13, 22 May 2015 (UTC)


 * Comment Frankly folks, this discussion is wandering off into cross purposes and irrelevancies to the extent that it is getting ridiculous. The GIF vs XXX discussion is about trivialities and they are getting mixed up with matters of personal taste that should have been shed in primary school. People who think the current pictures, irrespective of file type, are rotten, are free to provide replacement diagrams that everyone will love and everyone will understand irrespective of medium. Such concerns are not material for wasting people's time in RFCs. JonRichfield (talk) 07:54, 22 May 2015 (UTC)
 * Response to the RfC: I find the static images much easier to understand than animated ones. Maproom (talk) 06:59, 23 May 2015 (UTC)
 * Oppose: The use of the animated GIF images. It is completely unclear what the images are conveying.  What exactly do the red wires represent?  It is unclear.  The static images, on the other hand,  are completely clear as the red wires are obviously those wires carrying current.  85.255.232.92 (talk) 07:48, 23 May 2015 (UTC)

Designation "3-way"
The switches shown are more properly described as SPDT - "3-way" just describes the number of connection terminal and appears to be a US peculiarity and misleading to non-US readers.

http://en.wikipedia.org/wiki/Switch

Is more accurate —Preceding unsigned comment added by 86.150.101.226 (talk) 11:06, 17 December 2009 (UTC)


 * I've added a note to explain the difference between American and UK terminology. SPDT is unambiguous and is the technical description.  In the UK, we count how many switches in the circuit, hence "two-way".  In the USA, switches are described by the number of terminals.  Both usages are confusing since each switch can only be in two different positions.  It is now rare in the UK to see SPST switches on sale because the extra cost in having the extra pole is minimal.  I've actually seen "Carter" wiring in the UK (where it is marginally less dangerous because light fittings have two inner contacts an an outer metal that is supposed to be earthed).  I would never use the "Carter" wiring system, of course, but it is tempting for lazy electricians for certain layouts in older buildings.    D b f i r s   13:02, 22 October 2010 (UTC)


 * One could also argue that there are 3 "things" in the system, that is two switches plus a light bulb. The picture on the box depicts a light bulb snuggling between two switches - but why call this a "3-way"? For that matter, why designate pin and socket connectors as "male" and "female"? It makes little sense.104.172.216.137 (talk) 20:49, 27 February 2017 (UTC)


 * Don't expect common usage in any given jurisdiction to "make sense" according to some universal language. It often comes from arbitrary historical choices and commercial successes or failures. The best Wikipedia can do is to document the various terminologies, and the reasoning (if known, and however tenuous it may be) behind the terms. Reify-tech (talk) 21:06, 27 February 2017 (UTC)

Carter System confusion
Paragraph 3, Carter System, has me confused. The statement: "The advantage of this method is that it uses just one wire to the light." Is this correct? The light still requires two conductors, one from each switch. True, it is unclear which conductor is hot and which is neutral (since both conductors can be hot or neutral, depending on switch positions). But there still must be two conductors (wires) to the light, not one. --Rtmorgan (talk) 00:08, 10 November 2009 (UTC)
 * I've rephrased it. IN spite of finding several old books on house wiring on the Internet Archive, I still haven't found a reference that shows this system or tells me who Carter was. --Wtshymanski (talk) 02:17, 10 November 2009 (UTC)
 * Jimmy Carter, perhaps? Looks like it would be the way he would wire a 3-way switch!  (sorry, couldn't resist :-))  Anyway, that sentence looks much clearer, thanks!  --Rtmorgan (talk) 15:50, 11 November 2009 (UTC)
 * While he has been called history's greatest monster, I don't think we can blame the wiring system on the former President. The research continues...the Internet Archive is growing all the time and some day somone's going to digitize the crucial pamphlet or book. --Wtshymanski (talk) 14:18, 12 November 2009 (UTC)
 * It's fun to use Google Translate to read other language versions of this article. The Germans call the neutral-swapping system the "Hamburg circuit" and say not to use it.  The French don't have a name for this form of "come and go" switching but say not to use it.  And the Dutch call it the "French" or "Wrong" system.  No-one knows who Carter was...--Wtshymanski (talk) 14:41, 22 March 2012 (UTC)

There is a need for answers to these questions. WHAT IS a "four way switch" and how does it work? — Preceding unsigned comment added by 208.104.144.118 (talk) 10:19, 29 May 2013 (UTC)
 * A four way switch is a double pole single throw. (DPST) switch. It just swaps the two travelers each time it is moved. The hot and neutral aren't connected to it.--Canoe1967 (talk) 21:32, 30 May 2013 (UTC)
 * Years later....Found a diagram in a 1905 publication by the "International Textbook Company" that shows both the "Carter" system (not named as such there) and the conventional system, and it says either can be used. So this system was still legal in 1905 at least. No mention of grounding the neutral here. --Wtshymanski (talk) 05:18, 19 December 2018 (UTC)