Talk:Electrical systems

Three-phase systems
I'm not sure how much info we actually need about these. "These are industrial and often carry higher voltage (and higher maximum current) so leave them alone unless you know what you're dealing with." Maybe leave it at that. If some American wants to sneak 480V devices into Canada and watch them burn out when connected to the 600V mains, that's a question for an industrial electrician... not a travel guide. K7L (talk) 23:43, 2 November 2012 (CET)
 * Spot on! -- (WV-en) A l i c e ✉ 06:37, 3 November 2012 (CET)

I do see some problems with the latest edit:
 * "an outlet for a clothes dryer in North America may be 240 volts, similar to that of Europe for ordinary small appliances. However, differences in the neutral wire and number of phases render it incompatible, as well as extremely dangerous"

Really? A 240V North American clothes dryer is single phase. The only difference (other than line frequency) is that the transformer supplying that 240V has a neutral centre tap.
 * "Even if the initial hook up works, the circuit breaker may not close when it should, and cause a fire."

If the circuit breaker does not close, the whole thing remains turned off. Nothing happens. How is this dangerous or about to catch fire? K7L (talk) 17:07, 25 November 2013 (UTC)
 * Pretty sure what was meant was "the circuit breaker may not open when it should". But otherwise, I think we shouldn't be encouraging people to experiment with relatively high-voltage electrical wiring. If you know enough to get it right, then you have nothing to learn from this article anyway. --Bigpeteb (talk) 14:29, 26 November 2013 (UTC)


 * The North American clothes dryer outlet isn't any higher voltage than the typical every-day familiar outlets in most of the world. Actually, it can be argued the North American clothes dryer outlet is LOWER voltage, because relative to earth/ground, it's only 120V.  (ie. If you get electrocuted from a North American clothes dryer, it's only 120V that you'd feel.)--24.57.130.156 05:43, 21 February 2015 (UTC)Justin

Wikibooks
A Wikibooks guide to this topic has been imported to Wikivoyage and since deleted there. The original page is preserved at Talk:Electrical systems/Wikibooks and the contribution history can be found here. Please copy any useful information across (with appropriate attribution) to this article. --Nick talk 21:56, 11 February 2014 (UTC)

electric vehicles & photovoltaics etc
There should be sections added for electric vehicles, photovoltaics and perhaps other means of generating electricity such as thermoelectric cookstoves, kettles with USB plugs and portable fuel cells. LeeColleton (talk) 08:01, 29 November 2014 (UTC)


 * Good. Start writing such sections when you have the time. Thanks. Ikan Kekek (talk) 08:24, 29 November 2014 (UTC)


 * P.S. Welcome to Wikivoyage! I see that was your first post. This site is totally reliant on unpaid volunteer editing, so everyone is urged to plunge forward and add content that they notice is missing. So that's why I reacted as if you had volunteered to add the sections you described above. Ikan Kekek (talk) 08:29, 29 November 2014 (UTC)

Photos?
How did that article end up on the main page without even photos of the particular socket/plug types? PrinceGloria (talk) 05:42, 1 December 2014 (UTC)
 * Yes we really need pictures of each type of plug, maybe as a gallery? Nicolas1981 (talk) 08:48, 14 December 2014 (UTC)
 * ✅ ϒpsilon (talk) 09:59, 14 December 2014 (UTC)


 * That definitely improves the article, but I find the British plug too small to see without clicking on the photo. Is there room on the page to enlarge it? Ikan Kekek (talk) 15:08, 14 December 2014 (UTC)

A whole slew of corrections!
Corrections to some misinformation:

'''Re. converters vs. transformers, frequency, and waveshape of generators and inverters:'''

Just because a device is "electronic", does not mean a transformer or high-quality generator must be used for voltage conversion! Many electronic devices have switch-mode power supplies (SMPS), which work just fine on voltage downconverters, low-quality generators, and even inverters that produce square-wave and sawtooth-wave electricity. (Some electronic devices can even work from DC applied to their AC inputs!) That's because many SMPS designs used in electronic devices internally rectify the AC power to DC already, before any further processing is done! Hence the waveshape does not matter, AND NEITHER DOES FREQUENCY, so it's fine to connect such devices to almost any AC power source, from archaic 25 Hz to aircraft 400 Hz and everything in-between (and even beyond), as long as the voltage is within specification.

Furthermore, the claim in the article about clocks regulated by AC frequency needing a sine wave is untrue for many clocks. Digital electronic clocks (that are regulated by AC frequency) can use any waveshape; the timing circuitry merely counts when the electricity flips polarity -- it doesn't care what the "shape" of it is as it oscillates between the two polarities. (There are some waveshape issues for the linear power supplies used in typical electronic alarm clock radios -- see paragraph below.) For MECHANICAL clocks powered by an AC motor, yes, a sine wave is ideal... and may even be necessary for SOME such motors... but many synchronous AC motors in these clocks will still run (noisily) on a square wave. For electronic clocks and mechanical clocks with somewhat-forgiving motors, a voltage downconverter is fine, provided it has no DC bias and can handle inductive loads. (See next paragraph.)

Electric devices with AC motors, and electronic devices with linear power supplies, may not work on SOME voltage downconverters, but may still work on others. They key thing to understand is whether the downconverter has a DC bias or not, and if it can handle the back-EMF of the device's internal transformer or motor. Downconverters that have a DC bias (as is the case with simple "half-wave rectifying" converters that cut off half of each power cycle) can NOT be used. But downcoverters that use a "wave chopping" technique similar to lamp dimmers, "balanced" so there's no DC bias, and have snubbers to handle the back-EMF of inductive loads (similar to how variable speed motor controllers are designed), can actually be used to power some electronic devices with linear power supplies (internal transformers) and some AC motors!

'''Re. fluorescent lights and frequency:'''

Unlike the article's claim that fluorescent lights require their specific design frequency, many types of fluorescent lights (eg. those with electronic ballasts) can actually work on a wide range of frequencies. This includes just about every "compact fluorescent light" (CFL) where the inverter/ballast is an integral part of the entire lamp. (See the previous section on electronic devices using an SMPS.) Note that many portable flashlights/torches with a small (~ 15 cm long) fluorescent tube run on DC batteries, which again proves that not all fluorescent lighting is frequency-dependent!

Simple Pre-Heat fluorescent lights that use "glow-starters" (and which only have a single choke that's frequency-dependent) can still work at a slightly-lower-than-design frequency. Such a lamp designed for 60 Hz may still work at 50 Hz, albeit with lower brightness, and possibly a few more flickers on start-up until the lamp's mercury vapour is sufficiently ionized. Cheap 60 Hz desk lamps that require the user to hold an "ON" button for an extended period of time and then release it for the lamp to come on, are the easiest Pre-Heat fluorescent lights to force 50 Hz power! Just hold the button longer.

The only concern is when putting Pre-Heat choked and "magnetically-ballasted" fluorescent lamps designed for 50 Hz on a 60 Hz supply; this will allow too much current to flow through the tube, and could decrease the tube's lifetime or burn the lamp's switch contacts a little.

Rapid Start and Instant Start fluorescent lights with "magnetic ballasts" may not be very frequency-tolerant, but since these are rarely ever found in portable lights, most travellers need not worry about this.

'''Re. quality of generators:'''

Just because a generator may run on petrol/gasoline, doesn't necessarily mean it's bad! The type of fuel is completely irrelevant to the quality of electricity it produces! Heck, it could even be a steam engine, and still produce perfectly fine electricity! (In fact, industrial power plants like nuclear, coal, gas, oil, geothermal, concentrated-solar, etc. use steam to spin the generators!) So it's perfectly feasible and within reason for a petrol/gasoline engine to spin a mighty fine quality generator at a well-regulated speed, without issues.

There is nothing wrong with petrol/gasoline.

As for speed, that's irrelevant too. The "proper" speed for the generator depends only on the frequency of electricity it is supposed to produce, and how many magnetic poles (always a multiple of 2) are used in its design. The formula is:

{speed_RPM} = {frequency_HZ} * 120 / {poles}

A 1500 RPM generator has 4 poles and produces 50 Hz power. A 1800 RPM generator has 4 poles and produces 60 Hz power. A 3000 RPM generator has 2 poles and produces 50 Hz power. A 3600 RPM generator has 2 poles and produces 60 Hz power.

There is nothing wrong with 2 pole designs. In fact, some of the world's largest electric power plants use 2-pole generators!

And the article's claim that "If the engine speed is 3,000RPM or more, it is not a good machine." is complete bunk! For example, airplane jet engines typically spin at 12,000 RPM. (That produces 400 Hz, using a 4-pole generator set) Does that mean every jet engine's generator set is "not good" and inappropriate for powering the aircraft's "sensitive" and "expensive" avionics!?? And some large state-of-the-art power plants that produce 50 Hz and 60 Hz electricity employ large hydrogen-cooled turbine generators that spin at precisely 3000 and 3600 RPM, respectively! It's a rather bold statement to say the world's most advanced power plants are "not good", just because you don't like their rotational speed! (Keep in mind these were designed by some of the most intelligent mechanical and electrical engineers in the industry, specializing in fluid dynamics and electric power generation!)

What REALLY matters in selecting a generator is: * How "clean" is the output waveshape, which is largely dependent on how "cleanly" the field excitation current is regulated. * How stable is the output frequency, which depends on how well the engine speed is controlled. Issues like all-mechancal governors vs. electronic governors should be considered, as well as the specific moment of intertia of the generator set's flywheel. * How stable is the output voltage, which depends on how well the rotor is magnetically coupled to the stator, how efficient are the coils and cores, how responsive is the field excitation regulator, and of course how stable is the speed.

Vacuum cleaners and frequency:

The "rule of thumb" that vacuum cleaners can not be used at other frequencies is not a "universal law of physics". Powerful INDUCTION MOTORS are frequency-sensitive, yes. But UNIVERSAL MOTORS (ie. those with commutators and field coils) are quite frequency-tolerant, even for large powerful motors! Now, trying to use a 50 Hz vacuum cleaner on an airplane at 400 Hz might be a bad idea, but the difference between 50 Hz and 60 Hz is usually not significant enough to damage a universal motor in most applications... including power tools and vacuum cleaners.

24.57.130.156 05:32, 21 February 2015 (UTC)Justin


 * Most of the above sounds right to me, and the rest I cannot tell. I am much more a digital than an analog guy, though, so I will not attempt corrections, Do we have a volunteer? Perhaps the person posting above? Pashley (talk) 09:24, 21 February 2015 (UTC)


 * I think some of the stuff above, although correct, may be misleading. E.g. the discussion about petrol and diesel generators: yes, the cleanness of the waveform is what matters, but petrol driven generators or generators with high speed may tend to be lower quality (as it is possible to make these cheaply and there seldom is reason to choose this design for high quality generators). Few travellers have equipment to study the waveform, so this kind of hints are valuable. So, the question is not about whether high speed petrol generators are possible, but whether they are common enough to be relevant.


 * For the rest of the discussion, I suppose .156 is right, but the advice should be meaningful for the technologically uninitiated. Few people know what kind of motor or power supply is used in their hair dryer or laptop, and they should know when they risk frying the device, when testing at home is enough and what specific markings mean they are OK.


 * The text should be factually correct, so wordings about "tend to" etc. should probably be used in some more places – and for many situations more specific advice should probably be given (if the internals of the devices can be deduced).


 * --LPfi (talk) 13:29, 21 February 2015 (UTC)


 * I have to express a bit of reluctance (increasing in direct proportion to frequency) about this: "The only concern is when putting Pre-Heat choked and 'magnetically-ballasted' fluorescent lamps designed for 50 Hz on a 60 Hz supply; this will allow too much current to flow through the tube". I'd expect an inductor would allow more current (not less) to flow at the lower frequency, possibly being more prone to magnetic saturation. At DC, an inductor looks just like a plain old wire.
 * I wouldn't count on a vacuum cleaner to use a universal motor instead of an induction motor; usually the universal is a small motor, like the ones in portable power tools or variable-speed appliances. A large motor, like the one on a table saw, will more often be induction. If we do assume an induction motor, it may be necessary to state that assumption.
 * The main concern with line-powered clocks (and synchronous motors) is frequency; any device which counts AC cycles as a timebase will end up on the wrong time.
 * SMPS are a bit unpredictable as there are many designs; most just rectify the incoming line before doing anything else, but a few may attempt power factor correction - which complicates things. Many are rated point-blank "120/240V 50/60Hz" so that makes life easier; I'm glad to know that my ATSC TV will have no problem with the local line voltage anywhere on Earth. (The programme, on the other hand...)?
 * Petrol is usually avoided for large generators as it's difficult to buy this fuel without incurring road taxes; "coloured diesel" is available for generators without incurring the highway tax. There are also differences in motor design between diesel, two-stroke petrol (like a lawnmower engine, with oil in the fuel) and four-stroke petrol (like a motorcar). Electrically, it makes no difference; it just affects the motor and fuel. For small applications (such as portable generators at campsites) using gasoline might not be a major issue, but backup generators to power buildings will usually be diesel. K7L (talk) 21:10, 21 February 2015 (UTC)

Three phase systems
I just read that electricity in USA is not delivered as three-phase to normal households. That explains why people have insisted on it being available only in commercial settings, removing my tries to word it otherwise.

To make it clear: over here electricity is delivered as three-phase, but just one phase is used at the outlet (often also the cable from the distribution board carries just one phase). As three-phase electricity is available, also three-phase outlets tend to be available at modern houses, as they may be needed occasionally (cottages, old houses in the countryside and apartments may have only one phase delivered).

Perhaps a word or two should be said about delivering systems, as those knowing the system at home may believe they understand enough also abroad. In addition to the three-phase thing, I read parts of Belgium uses two-phase outlets instead of phase+neutral, which may lead to nasty surprises for some.

--LPfi (talk) 19:25, 2 March 2016 (UTC)


 * If Belgium is 230V AC line-to-neutral, that would mean that 400 volts is being delivered to three-phase outlets. Residentially? That's tempting fate. K7L (talk) 04:58, 3 March 2016 (UTC)


 * Three phase electricity is in general used for things that are stationary and require a lot of power like stoves or electric sauna stoves, you most certainly won't find them in every corner of your house. Also, three phase outlets are of a completely different size and shape than regular 230 V outlets. ϒpsilon (talk) 06:16, 3 March 2016 (UTC)


 * Yes (but this is Finland, not Belgium). The 400 V outlets are not found in normal rooms, but at the distribution board (possibly behind a lock), for some stoves (with the outlet not easily accessed) and perhaps in domestic workshops (also not easily accessed by children). I think the temptation to tamper with 400 V outlets or things you connect to them is rather marginal.


 * The thing about (parts of) Belgium is that the 230 V is delivered phase to phase (as in 230 V outlets across the pond but with 120° phases), not phase to neutral. Anything attached to the outlet gets the same 230 V as elsewhere in Europe, but somebody from here tampering with electrical equipment will suppose one of the pins is neutral, which may not be true.


 * --LPfi (talk) 08:50, 3 March 2016 (UTC)

SEO edits
While this article is a bit longer (8100 words versus 6437 words) and probably contains more information than the stuff on that other side it still gets slapped with a "duplicate penalty" due to 53% or 4254 words matching. Do have a look at Copyscape and try to bring that number down somewhat. While this article might not outdate as fast as some others, I am sure there are turns of phrase that could probably be improved upon. Hobbitschuster (talk) 17:22, 23 November 2016 (UTC)

Duplication
I recently added a section at Electrical_systems then noticed that much of it was already covered at Electrical_systems. (facepalm!) Is there a volunteer to merge those? Pashley (talk) 15:37, 17 July 2017 (UTC)

Does frequency matter?
Using the wrong voltage can certainly cause big problems, but what about the 50/60Hz distinction? I would imagine most devices do not care so the user need not worry about it & the article should say so, which it currently does not. However, I'm no expert on things electrical & do not want to add this without checking here first.

Are there devices where it does matter? Do some use the input frequency for timing? Does the output of a transformer depend on input frequency? Are there other issues? Pashley (talk) 16:53, 27 August 2017 (UTC)


 * Frequency matters, but only for a small minority of devices. The classic example would be a cheap line-powered alarm clock which uses the input frequency for timing, instead of being crystal-controlled. An entirely-mechanical clock might use a synchronous motor whose speed directly follows line frequency. An old-style fluorescent lamp ballast might simply be a large inductor (coil) in series with the incoming line; the lower the frequency, the more current passes through the coil to the lamp, which could have been problematic. A transformer may need to have a slightly bulkier metal core at a lower frequency (and wouldn't work at all on continuous DC) because of the need to avoid magnetic saturation; a transformer that works at 50Hz should work at 60Hz.
 * A purely-resistive device (like a heater or an incandescent bulb) won't care at all. Most electronic devices convert the line from AC to DC immediately (or as soon as the voltage has been stepped down); the frequency doesn't much matter in this case. Many computers are built for worldwide export, in such a way that only cords, plugs or adapters needs to change. The actual electronics are DC internally. Even fluorescent lamps are increasingly being built with electronic ballasts, or are simply being replaced with LEDs or other light sources. Frequency matters less than it used to. Motors running more slowly on 50Hz than on 60 cycles would be the most common symptom of a change in line frequency. K7L (talk) 20:15, 27 August 2017 (UTC)

Blackouts
Imho it should be mentioned that blackouts vary vastly in frequency even between rich nations. In Germany for instance the average end consumer has less than 15 minutes of blackout per year... Hobbitschuster (talk) 16:52, 7 April 2018 (UTC)
 * Yeah, and also inside countries between urban and rural areas. ϒpsilon (talk) 20:22, 7 April 2018 (UTC)

Euro plug and Schuko
There is a cautionbox saying that the Europlug won't make a tight enough connection into a Schuko outlet. I have never had that problem, and I suppose everyone is routinely using them that way here in Finland. Where would you otherwise plug your europlugs? There are no separate outlets for them. Is this different for other European countries? --LPfi (talk) 05:58, 8 April 2018 (UTC)


 * Possibly. In practice there are some (small) differences between sockets in European countries, both when it comes to the distance between the holes and their sizes (especially apparently older installations). Nevertheless, plugs virtually always fit, sometimes a little loosely and sometimes one has to use a little force. --ϒpsilon (talk) 15:25, 8 April 2018 (UTC)

The Bible quote isn't even remotely about electricity
So why are we so insistent on having it there? Some oversensitive backlash against supposed (or maybe real) "political correctness"? Hobbitschuster (talk) 00:58, 8 June 2018 (UTC)


 * There was considerable discussion at Travellers' pub. I thought we had a consensus that it should go.
 * Certainly I think the George Carlin quote is both more relevant & more amusing, obviously a better choice. Pashley (talk) 01:28, 8 June 2018 (UTC)


 * Actually, "organised lightning" really isn't a better-quality quote. The only reason it was inserted was to avoid mentioning any religion. K7L (talk) 01:35, 8 June 2018 (UTC)


 * On the face of it and disregarding the religion issue vis-à-vis the hypersensitive user who finds the Book of Genesis offensive, consensus never held the Carlin quote to be more than marginally preferable to the Biblical quote. However, once it became clear what said hypersensitive user's real endgame was, consensus rapidly turned toward the idea that taking a strong stand and discouraging any further attempts to bowdlerize the site was a more important consideration than the question of which quote was preferable. -- AndreCarrotflower (talk) 03:42, 8 June 2018 (UTC)


 * ...or in other words, quoting myself from the pub, "our Electrical systems article will not be substantially worse off in the long run if we have 'Let there be light' as the quote rather than the Carlin one, but Wikivoyage as a whole will be substantially worse off in the long run if we allow a culture to develop where editors have to walk on eggshells to avoid inadvertently hurting the feelings of every imaginable class of perpetually offended user." -- AndreCarrotflower (talk) 12:38, 8 June 2018 (UTC)


 * Are we still discussing this? I thought there was consensus in the pub to replace the "let there be light" quote in this article but not systematically remove religious quotes from other articles. I don't think I participated in that discussion, but I think the "let there be light" quote is clearly irrelevant to this article, and I'm disappointed to see that it's been re-added. —Granger (talk · contribs) 12:47, 8 June 2018 (UTC)


 * Coverage of the issue was spread out between two threads at the Pub (pub and pub), as well as at Talk:Clothes. If you take those three discussions as a whole, you can see that consensus changed rapidly once the user made a similar edit to the Clothes article. -- AndreCarrotflower (talk) 12:48, 8 June 2018 (UTC)


 * I disagree with that assessment—I think consensus developed that we shouldn't systematically remove religious quotes from articles, but I don't think the consensus for removing the irrelevant quote from this article ever changed. —Granger (talk · contribs) 13:05, 8 June 2018 (UTC)


 * I agree. As I see it, Andre's restoration of the biblical quote is unacceptable edit warring & violates a clear consensus. Pashley (talk) 14:01, 8 June 2018 (UTC)


 * There's nothing clear about the consensus, and if reverting vandalism or trolling is now considered equivalent to edit warring with said vandal or troll, then mark me as a proud "edit warrior" as every admin worth his salt should be. -- AndreCarrotflower (talk) 14:16, 8 June 2018 (UTC)

I think both the quote about organized lightning and the Biblical quote are fine, but I think that now we've switched to the organized lightning quote, there is no need to switch back again. Selfie City (talk) 14:40, 8 June 2018 (UTC)


 * Never mind. I just looked at the Understand section. Selfie City (talk) 14:41, 8 June 2018 (UTC)


 * The author(s) of genesis didn't even have an idea of the existence of electricity. Carlin is clearly talking about electricity. How fitting would a quote from some ancient Greek bloke be in Musicals? Hobbitschuster (talk) 15:41, 8 June 2018 (UTC)


 * I think the best thing to do is to leave this alone for now. After a year somebody can replace the quote with something better (or suggest such a change) without any problems of principle, be it some of the suggested ones or something else. Anything we do now, on the other hand, is done in the context of the controversy. --LPfi (talk) 16:34, 8 June 2018 (UTC)


 * So return to what was there before the edits which caused this entire recent controversy? That would be consistent with our status quo bias. K7L (talk) 22:56, 8 June 2018 (UTC)


 * I would restore the Carlin quote. God creating light is not about electricity. It's an irrelevant quote. Ikan Kekek (talk) 08:17, 9 June 2018 (UTC)


 * I vote to restore the Carlin quote too. The quote from the Bible is about light and not about electricity. Those are two different things. In the case of the Clothes article, the Biblical quote was replaced with one that was not as good, and that was why I voted to keep the Biblical quote. In this case, the Carlin quote is clearly much more relevant than the Biblical quote. While we should absolutely not replace quotes from the Bible (or any other religious text, for that matter) simply on the account of some oversensitive person being offended, let's also be careful not to take it too far in the other direction. If there is another quote, but it secular or religious that is better than the current one, then the current one should be replaced, again regardless of whether it's secular or religious. The dog2 (talk) 20:02, 11 June 2018 (UTC)


 * I disagree, as the generation of light was one of the first profitable applications of electricity and the Carlin quote is not as good. Hopefully we don't end up like Uncyclopedia - with multiple, unfunny, fabricated quotes at the start of every page to add nothing of value - but "let there be light" seems harmless (except to vampires). K7L (talk) 20:11, 11 June 2018 (UTC)


 * But the creation of light, come on, that has nothing to do with electricity. Light comes from stars, fire, moons, planets, comets... Ikan Kekek (talk) 20:16, 11 June 2018 (UTC)

Exactly. For cavemen, light came from the sun and from fires. So the creation of light had nothing to do with electricity. The only electricity they would have encountered was lightning, but they would not have been able to harness it back then. The dog2 (talk) 21:52, 11 June 2018 (UTC)


 * It looks to me like we have pretty much of a consensus to go back to the Carlin quote for this article. AndreCarrotflower, now that the argument to go back to that quote isn't from people who want to scrub the entire site of Bible quotes, would you be willing to concede this point? Ikan Kekek (talk) 23:08, 11 June 2018 (UTC)


 * The Carlin quote is decent, and can replace the Genesis quote. /Yvwv (talk) 02:41, 13 June 2018 (UTC)


 * So if there are no objections within 24 hours of this posting, I'll go ahead and restore the Carlin quote. The dog2 (talk) 17:57, 18 June 2018 (UTC)


 * Perhaps we should have no quote at all. Adding this just for the sake of doing so doesn't improve the article. K7L (talk) 23:24, 18 June 2018 (UTC)


 * Depends on what you mean by "improve". It's funny, so it may improve the reader's experience of reading the article. Ikan Kekek (talk) 00:34, 19 June 2018 (UTC)
 * So what's the verdict then? The dog2 (talk) 00:41, 21 June 2018 (UTC)

Well, I think its pretty certain that Clothes will include a biblical quote; I would say we ought to restart this and ask people whether they want the Carlin quote, the Biblical quote, or no quote at all, and see where consensus goes. Because nothing's definite right now. Selfie City (talk) 00:45, 21 June 2018 (UTC)
 * It seems to me this discussion demonstrates that there continues to be consensus for using the Carlin quote instead of the Genesis quote in this article. —Granger (talk · contribs) 00:58, 21 June 2018 (UTC)
 * Seems like a consensus to me, too. Clothes is not relevant to this discussion: the Biblical quote there is obviously topical. Ikan Kekek (talk) 03:24, 21 June 2018 (UTC)
 * But the idea of having no quote came up at the end of the discussion, but that has proven to not have any influence on where consensus is going. Selfie City (talk) 15:01, 21 June 2018 (UTC)

Grounded devices
It seems grounded outlets aren't easily available everywhere, see e.g. Brazil. Do we have any advice for that? We now just say that you shouldn't use such outlets for devices with a ground pin, which isn't really helpful, and I think an adapter for this use is safer than makeshift solutions such as that suggested for Brazil.

Most devices you bring may not need grounding, and you might be able to choose devices that don't, but e.g. this laptop's charger is grounded. Can you get around that?

–LPfi (talk) 21:22, 8 January 2023 (UTC)

CB radio
Can someone please add an article to Wikivoyage covering the travel topic of "CB radio", "radio communication", or "rural telecommunication"? I am trying to find out if I might need a two-way radio (e.g. CB radio) for an upcoming roadtrip across the USA. This is primarily to be able to call for help in case of an emergency in a rural area without cellular telephone service but could also be useful to get information from other travelers about traffic and road conditions. However, there is a lot of mixed information online about CB radio. Assuming that anyone is within listening range (which is quite limited for citizens' band) I have read reports online that CB radios are no longer commonly used in the USA and specifically that emergency personnel in the USA often do not monitor the CB radio emergency channel any more in which case an emergency signal should actually be broadcast on Channel 19 (the most commonly used channel) instead of Channel 9 (the emergency-only channel). If any Wikivoyagers have experience with CB radios in rural areas, that will be a very helpful article to add to Wikivoyage. The alternatives to a CB radio might be a portable ham radio (which requires an FCC license in the USA) or a satellite emergency texting service (available from Motorola and Garmin). Nicole Sharp (talk) 16:24, 17 September 2023 (UTC)
 * We try to cover a bit of the theme in Electrical systems and Mobile phones. I assume you are right in that the CB range is too short to be much help in an emergency – cars on the same road are more reliably alarmed by visual means. However, I am European and have no experience of CB radios. On marine VHF it is common practice to monitor more than one channel (usually two), a separate emergency channel nobody listens to sounds odd. One more option would be an EPIRB (or rather its on-shore equivalents), I think those are discussed in some itinerary, shortly mentioned in Cruising on small craft, but not discussed in any general article.
 * I agree that a more thorough discussion would be good to have, preferably about all different consumer two-way radios (perhaps including ham options). However, I don't know enough to write it.
 * –LPfi (talk) 17:36, 17 September 2023 (UTC)
 * Visual communication is an idea that I had not thought of. Trying to send smoke signals is likely dangerous and illegal (road flares are also not safe to keep inside a car) but at night a green laser pointer could be used (though this may still be illegal in some locations and is hazardous to aircraft).  I would suggest putting all of this instead under a comprehensive article for " emergency communication " to specifically cover different methods on how to get help when stranded in rural areas (whether on land or water).  Nicole Sharp (talk) 17:49, 17 September 2023 (UTC)
 * Emergency communication is also likely to be different than normal (non-emergency) communication which is a good reason for having it covered in a separate article. For example, CB radios can be illegally modified to increase their range, but I do not know if the USA FCC allows exceptions for emergency use.  The Motorola satellite texting service allows free text messages by satellite for emergency use only whereas Garmin requires a paid subscription even for emergency use only.  This is from a small/affordable satellite transponder that attaches to any smartphone.  That is likely a better alternative to Terrestrial radio but the CB radio could also be useful in non-emergency situations for general traffic updates from other drivers using CB radios.  Nicole Sharp (talk) 17:56, 17 September 2023 (UTC)
 * @Nicole Sharp, assuming your question is related to the upcoming eclipse, I don't think you need to worry about this. You're not going to be in the middle of nowhere.  Cell phone coverage should be good for all of your trip if you stay on the interstates and major highways (and route around the National Radio Quiet Zone on the western point of Maryland), and for nearly all of your trip even if you don't.  See https://www.whistleout.com/CellPhones/Guides/us-cellular-coverage-map for a map.  Any given spot might have poor signal, but most of the large cell phone dead areas are north or further west of New Mexico.
 * If you think it would be fun to use a CB, then you can get one. Over-the-road truck drivers, especially those who've been doing it for years, still use CBs.  They're useful if you want to ask someone nearby what's causing the unexpected traffic jam, or if you want to warn others about a traffic hazard.  However, I don't think I've seen one in a personal vehicle since the 1980s, and they are more useful if you are on major trucking routes than if you are in the middle of nowhere.  The range for a portable set (i.e., no permanently installed antennas) can be up to about three miles.  A satellite phone would be more effective ...but if you're just driving there and back, I think that would be overkill. WhatamIdoing (talk) 21:21, 17 September 2023 (UTC)
 * An emergency communication device would be for both everyday local use as well as for travel use. Large areas of Western Maryland (where I live) and West Virginia (near where I live) do not have cellular telephone service, as well as large areas of New Mexico.  For local travel, I try to avoid those areas specifically because I am afraid of being injured or having my vehicle break down and not being able to call for help.  The map that you linked to is not accurate since I know for a fact where local dead zones are (e.g. New Germany State Park), at least for AT&T.  Even on the official AT&T map not all of the dead zones are marked, unless they've recently added coverage since the last time I "voyaged" there.  I am worried that coverage in rural southeastern New Mexico (the parts of the state where UFO crashes are alleged) might be similar to coverage in rural western Maryland.  A lot of the cellular telephone dead zones also appear to specifically be around USA National Forests, where backcountry camping is free.  Most major roads and highways are going to have cellular telephone coverage so my main concern about CB radios is that they are not going to be useful in an emergency if no one is listening to CB radios in rural areas not near major trucking routes.  I read that small towns used to have CB "base stations" (with a much larger reception range than a portable CB radio) that were monitored 24/7 for emergency broadcasts but I don't think these exist any more?  Nicole Sharp (talk) 21:53, 17 September 2023 (UTC)
 * Generally, in a small town, "outdated" equipment will be kept for as long as it works, and then discarded. Consequently, I don't think you could predict where it would/wouldn't work, especially since terrain matters so much.  Any place, even in the middle of a city with excellent cell phone coverage, can have "that one spot" with poor coverage, and the same is true for any type of radio-based communication.  You could be within walking distance of a town with a CB station and still not have CB coverage for the particular spot you happen to be in. WhatamIdoing (talk) 01:05, 20 September 2023 (UTC)
 * Agreed. The chances of ending up being stuck in a spot in the middle of nowhere without cellphone coverage but with somebody monitoring a CB somehow seem lower than those of getting stuck in a place that has neither. If you're traveling to the middle of nowhere, some form of satellite communication seems like the logical choice. As far as I can tell, there are three options:
 * Personal Locator Beacon (PLB) - push a button and wait for SAR to show up. This utilizes global infrastructure that is used for aviation and nautical purposes. They communicate via Sarsat, which is directly monitored by SAR. No subscription, but also no messaging. But you can have it registered so SAR can contact somebody who knows about your travel plans. Typically also transmit a signal on 121.5 MHz for SAR to use as a beacon to home in on.
 * Satellite messengers like the already mentioned Motorolas and Garmin inReach, etc. - adds text messaging via proprietary services that usually require some form of monthly subscription. They use different satellite networks (Garmin and Zoleo for example use Iridium), and there is some kind of company or organization responsible for relaying your distress signal to SAR.
 * Satellite phone - best for actual communication but super expensive, afaik.
 * El Grafo (talk) 10:56, 21 September 2023 (UTC)
 * These can be rented, but you're probably looking at $50 a week for the most basic options, going up to $100 or more. A standard check-in plan with a buddy ("It's Monday morning, I'm here, I'm going there.  I plan to check in with you when I get there, probably in about three hours"), on the other hand, costs whatever you pay for a few texts per day. WhatamIdoing (talk) 16:23, 21 September 2023 (UTC)
 * I thought of the same thing. Assuming that I am returning to the same hotel I left from, I can leave a note that if I am not back by such-and-such time then an emergency has happened and they should contact the police to start a search party.  I figure with enough water and food in the car, I can be stranded for at least a few days before the situation becomes a real emergency.  Nicole Sharp (talk) 02:07, 24 September 2023 (UTC)
 * Letting somebody know about your intentions is always a good idea regardless of what communication devices you carry. And thb, for a road trip it's probably all you need as "insurance". El Grafo (talk) 09:09, 25 September 2023 (UTC)

I talked to AT&T and they admitted that their map may contain errors. What the map provides is areas that should have coverage but there can still be localized dead spots that aren't always marked on the map. AT&T also said that 911 calls can still sometimes work even in areas with no service from AT&T since the 911 calls have the highest priority and can sometimes piggyback off a third-party cell tower that won't otherwise show as a cell phone signal for an AT&T phone. Localized dead spots are maybe where a cell phone booster could be most useful, since it is technically in a coverage area but the signal is otherwise obstructed or too weak. Using the official AT&T map, there isn't really anywhere completely without service between Maryland and New Mexico other than the USA National Radio Quiet Zone in West Virginia and the area around Carlsbad Caverns National Park. For the very rural areas such as USA National Forests a CB radio is only going to be of use to get help in an emergency if the USA Forestry Service is using CB radios. Otherwise satellite or ham radio are likely the only practical alternatives. A CB radio still sounds like "fun" though and could be useful for traffic reports. Nicole Sharp (talk) 16:55, 27 September 2023 (UTC) According to the Cobra user manual, "a CB radio can... get local information to find a destination [and] suggest spots to eat and sleep". I didn't even think of that. I was thinking of CB radios for emergencies and traffic updates but they might be even more useful to be able to get recommendations from locals and other travelers on places to sleep, eat, or sightsee. Nicole Sharp (talk) I would recommend prioritizing information about cellular telephone coverage available from locals than any information about cellular telephone coverage from a map provided by the phone company. For example, Mammoth Cave USA National Park is listed by the National Park Service as having no cellular telephone coverage at the campgrounds, despite being in the coverage area for the official AT&T map. Nicole Sharp (talk) 15:40, 30 September 2023 (UTC) Regarding CB radios, how do you deal with leaving the window cracked open for a magnetic CB radio antenna mount? Won't that break the vehicle cabin air conditioning in summer, be freezing cold in winter, let rain onto the seats, and provide easy access for thieves? Nicole Sharp (talk) 15:40, 30 September 2023 (UTC)

"Bad physics"
About this recent edit, P=U2/R gives the fact that doubling the voltage will quadruple the power. Ypsilon (talk) 19:14, 29 February 2024 (UTC)


 * Yes, double the voltage & you get twice the current for the same resistance. Power is voltage times current so four times the power.
 * I reverted the edit. Pashley (talk) 01:33, 1 March 2024 (UTC)