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The current in a 110 volt line pulses into the neutral line.
The current in the 220 and higher 3 phase lines pulses from multiple lead lines into the neutral line.
All the current travels from the lead line into the neutral line.
To prove this DIODES are used to convert AC into DC.
— Preceding unsigned comment added by 108.89.36.16 ( talk) 01:02, 27 January 2014 (UTC)
References
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I was going to put that unlike DC, AC does not need to return to its source, as it can flow to ground. However, I may be wrong on two counts... Can DC flow to ground as AC can? And also, am I wrong about AC somehow? I think I'm confused... —Preceding unsigned comment added by ReignMan ( talk • contribs) 11:01, 1 December 2007
The AC or DC can flow to ground, if you connect one terminal of a DC supply to ground then you can supply a load via the other terminal of the DC source and return it to ground. The reason AC tpically does this is that "ground" is established at the generation plant and at the customer premises.
Remember the electrons don;t care if they always go the same way or if every so often they reverse direction, so AC and DC behave the exact same way in a lot a respects, like when discussing grounds.
This article also states that the since wave is the most efficient form of energy transfer - this is not the "real" reason AC is sinewave. Sinvewaves are what you get when you have a rotating magnetic field (e.g. in an alternator) - it is quite hard to generate a triangle or sawtooth or square wave mechanically as it requires rapid cahnges in direction. Technically this means the sine is more efficient but it's a bad way to state it. —Preceding unsigned comment added by 60.234.222.212 ( talk) 06:52, 14 October 2008 (UTC)
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
Why is this discussion done in terms of voltage? I realize that ac voltage often accompanies ac current, but seeing as how this is an article about ac current it seems better to just stick to ac current. The math won't be any different, so I just don't see the reason to switch to voltage for calculations. —Preceding unsigned comment added by 146.115.120.149 ( talk) 20:18, 20 September 2006
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
Just wondering if anyone else finds it confusing that the multiplication sign is an 'X', the symbol for cross product. I realize that this or a dot are often used, but with the inclusion of the sine function in the equation already it may be misleading. -- Bmalicoat 23:47, 26 October 2005 (UTC)
The wording "His design was a primitive precursor of the modern transformer, called an induction coil" is not very NPOV.
I'd like to see some pictures of AC in action words can't describe it well enough. -- Cyberman 02:30, 10 Feb 2005 (UTC)
I think this page is nice. Congratulations to those who've been working on it. I nominated it for featured articles. A picture would be nice, though. Power cables, transformers or something. Washington Irving | Talk 23:21, 25 Mar 2004 (UTC)
I could write a part about transforming DC->AC through a solenoid- condensator circuit and a triode. Anyone think this is useful and/or fitting here?
-
Xorx77 17:09, 28 Mar 2004 (UTC)
I changed the usual Teslaphile stuff to give due credit to some of the other critical workers in the field. Look guys, I know you venerate the guy, but the reality is that his contribution to the field, although undoubtedly important, was just one aspect of many advances in electrical engineering at the time. In particular, describing him as the father or inventor of AC makes a good book blurb but is totally unsupportable. Among the critical parts of the infrastructure he didn't invent were: transformers, the AC distribution system, AC generators, or meters. His major practical contribution was AC motors - and the first one he ever built that actually worked, was under contract to Westinghouse. Securiger 13:18, 21 Jun 2004 (UTC)
Actually the Tesla coil is an 'air core' power transformer: http://en.wikipedia.org/wiki/Tesla_coil. The historical sections of this article are a POV mess and require serious re-writing. Counterinduction. 09.33, 15/4/2014 (GMT)
— Preceding unsigned comment added by 129.234.252.66 ( talk) 08:34, 15 April 2014 (UTC)
I updated the sections on power and 3 phase systems, which are hopefully a bit clearer now. Also the section on earths and neutrals which had become a little muddled. The earth is not the same as a neutral. A neutral is used to form a complete circuit in a healthy system, an earth is used to provide a specified path for current during a fault. —Preceding unsigned comment added by 62.172.213.132 ( talk) 15:32, 23 September 2004
Did the guy who wrote this ever actually stick the probes of an oscilloscope into the wall outlet? —Preceding unsigned comment added by Rsduhamel ( talk • contribs) 21:21, 27 December 2004
The article currently has a lot of stuff that is covered in other articles; three phase, grounding, etc. I think the discussion here could be compacted since details are only a mouse-click away. I also cleared up some leading spaces in the talk page - not everyone is signing contributions - use the button for signatures in the editor or else manually put --~~~~ at the end of your comments. -- Wtshymanski 17:26, 1 Jun 2005 (UTC)
I consider the concepts of electrical current/voltage, resistance/reactance and power to be sufficiently different that they should not be merged, otherwise the combined article will become too long and very difficult to organize clearly. I note that there is inadequate discussion in these articles of non-sinusoidal waveforms, particularly of the substantial 3rd and 5th harmonics generated by the non-linearity of standard power transformers - that would make a combined article even longer. Then there are the square and 2-step waveforms of DC-AC power converters. I recommend keeping these three separate but consistent, with appropriate cross links. As a retired electrical engineer, I could try to start this process, but would do so only when agreement is reached on separation. JohnSankey 15:31, 5 October 2005 (UTC)
Can we remove some of the merge templates then?-- John 23:45, 16 October 2005 (UTC)
Just to note that "mains power" is a British term. I have never heard it used in North America. JohnSankey 22:59, 5 October 2005 (UTC)
Why do these articles simply redirect to this article, when this article makes no mention of them? —Preceding unsigned comment added by 62.56.57.235 ( talk) 10:45, 17 October 2005
I am sorry if I sound negative, but this article/entry (Alternating current) is un-organized, and even though it's extraordinarely short for such an important and vast subject, it feels too long to read.
The consequences of the bad architecture of the entry, is that even contributors have trouble striking the right balance when trying to add relevant information. For example, Nikola Tesla is under-represented, even though he has almost single-handidly produced virtually all the elements of the puzzle necessary for the AC power system (I won't spend time documenting this point, if anyone thinks it's open to dispute, I'm willing). I don't blame it on anyone's agenda, but simply, on the fact that the article is discouraging of contribution. I have tried, anonymously, to correct few of the more evident errors, and am preparing to beef up the body on Steinmetz and Tesla. Still, every time I think of this wikipedia entry, I feel pain in my stomach, so I keep putting off the big work for another day. Old-fool 17:56, 21 October 2005 (UTC)
I don't know what you mean by power lost = I^2 * R. This is supposed to be the equation for power transmitted, and since V=I*R, power = V*I also. Therefore, I don't see why the power equation explains why current affects power lost and not voltage. Can someone clarify this please? —Preceding unsigned comment added by 24.184.127.141 ( talk) 03:47, 3 November 2005
I think you should explain it since the present simplicity is deceptive and also confusing due to the question of why I should think about I^2 * R instead of V^2/R. —Preceding unsigned comment added by Jcline1 ( talk • contribs) 13:39, 26 November 2007 (UTC)
I would suggest that you read Wikipedia articles on alternating current and direct current. Nikola 22:54, 28 November 2005 (UTC)
This is a shockingly sparse and badly organised article considering the importance of AC power in the world. —Preceding unsigned comment added by 148.197.54.206 ( talk) 15:12, 1 December 2005
Volt-amp redirects to this article, but I don't see any mention of it here. In particular, I'd like to know how volt-amps are related to watts. (I thought were the same, but then why is a UPS I'm looking at rated at "500VA" but "300W"?) - dcljr ( talk) 04:50, 16 January 2006 (UTC)
“ | It is generally accepted that Nikola Tesla chose 60 hertz as the lowest frequency that would not cause street lighting to flicker visibly. The origin of the 50 hertz frequency used in other parts of the world is open to debate but seems likely to be a rounding off of 60 Hz to the 1-2-5-10 structure, called a set of preferred numbers, popular with metric standards | ” |
What other parts of the world? I assume other than the U.S.A. If you take a look at the frequencies used you will notice that 50 hertz is the most commonly used frequecy , with a few (but major) exceptions (mainly North America). It's a minor issue of how you put it , since I don't think all users of wikipedia regard this from the point of view of an american as we can't be all americans :)) —Preceding unsigned comment added by 82.76.35.22 ( talk) 07:36, 31 January 2006
See my comment above. I'm deleting the following passage and replacing it. Included here in case someone wants to rollback or merge. -- Psm 20:27, 1 August 2006 (UTC)
It is generally accepted that [[Nikola Tesla]] chose 60 [[hertz]] as the lowest frequency that would not cause street lighting to flicker visibly. The origin of the 50 hertz frequency used in other parts of the world is open to debate but seems likely to be a rounding off of 60 Hz to the 1-2-5-10 structure, called a set of [[preferred number]]s, popular with metric standards.
60Hz may also have been chosen as it would make for more convinent gearing ratios in electric clocks. A synchronus motor runing on 60Hz rotates at 3600rpm (or a submultiple therof) 3600 rpm through a 60:1 gear ratio is 60rpm (i.e. 1 rev/sec) with succesive 60:1 gear ratios giving 1 rev/min (for the second hand) and 1 rev/hour (for the minute hand) 87.113.7.148 17:48, 12 August 2006 (UTC)
The only difference between AC and DC is that AC alternate between positive and negative values as DC always stay positive...You can have a perfect sine wave which stay on positive values as a DC current. So the form of the wave as nothing to do with DC or AC. You can also have pulsed waves that can be AC. Magnitude have nothing to do here... —Preceding unsigned comment added by 65.92.142.247 ( talk) 22:48, 10 February 2006
When you are mixing two currents it's sure you can't tell at this moment whether its DC or AC because its both but usually the DC will be use to transport AC and then be divided again by a coil and/or capacitors. The result will be a positive sine-wave and a alternating sine-wave. —Preceding
unsigned comment added by
65.93.158.199 (
talk) 23:28, 22 March 2006
I forgot most of what i know of AC's history, but im pretty sure Edison hated it... I don't really remember, so I came here. I am dissappointed to find that this info isn't here, so I'll have to look elsewhere for now! Maybe I'll do some research and write it myself if I have time. —Preceding unsigned comment added by 74.130.112.57 ( talk) 01:42, 29 July 2006
I think this article needs a section on how the alternating current is generated and one on how direct current can be transformed into alternating current. —The preceding unsigned comment was added by 193.226.140.133 ( talk • contribs) .
I wanted to know exactly what happens with the three holes in an outlet. Since voltage is a difference, and a circuit must be closed to receive it, does only one of the leads vary, or both, in opposite phases from each other? If the latter, does that mean connecting the same terminal from two different outlets produces no current? If the former, does that mean one of the terminals has no power? Does the ground terminal connect directly to the ground or a building's structure, as opposed to running through a power cable? Badmuthahubbard 20:33, 19 August 2006 (UTC)
You have twisted pair but what about the twin lead we used to use for TV antennas? Some people used forms of twin lead for ham radio. Knob and tube and romex could be concidered twin lead as well. -- Gbleem 13:54, 2 September 2006 (UTC)
The article makes no mention of who first developed (or experimented with) the theory of alternating current...—Preceding unsigned comment added by 219.88.179.132 ( talk) 11:29, 7 September 2006
does alternating current have positive and negitive like direct current?-- Falcon866 02:35, 5 January 2007 (UTC)
The article on DC has an image showing the DC "symbol" that is used on electronics and such. I would assume there is a corresponding symbol for AC. I think it would be a good addition for the article to contrast it with DC. - AndrewBuck 22:49, 27 March 2007 (UTC)
Here on the Wikipedia, where a dozen articles go into great and varying detail on the standardization of European utilization voltages, we (used to ) find the light-hearted statement that American utilization voltage is 3 phase 110 volts. Sorry, it's not - not three phase, and not 110 volts. You won't find a reference for this because it doesn't exist. I've taken it out again, it's not relevant to the example. There's no salvaging the commented-out paragraph and I recommend it be deleted. -- Wtshymanski 21:13, 10 April 2007 (UTC)
The equation Vrms=Vpeak is only true if centered about the x-axis. If a dc-offset is considered the equation is invalid. Duty cycle must then be taken into account. Consider a square wave with 50 percent duty cycle, peak voltage of 1 volt, centered at half a volt. Rms voltage is then 0.707... Someone tell me I have had too much coffee tonight, and that I am in error. —Preceding unsigned comment added by 24.9.208.230 ( talk) 04:37, 30 November 2007 (UTC)
Why doesn't this article say which is battery power and which is wall-plug power. I always forget. I can't be the only one can I? —Preceding unsigned comment added by 81.138.12.194 ( talk) 11:13, 1 February 2008 (UTC)
The date of the first modern A/C station is wrong. The first such station was built by Ferranti at Deptford near London in 1891. It produced an A/C 10Kv supply, with transforner stations for each street served. Chasnor15 ( talk) 11:12, 28 March 2008 (UTC)
"HVDC systems tend to be more expensive and less efficient than transformers." This statement is wrong (or at least needs some justification), otherwise why would they use HVDC. HVDC systems can be more efficient at transporting large quantities of power, as there is no reactive power. The efficiency of the power electronics is increasing annually as new GTO's/IGBT's are developed. —Preceding unsigned comment added by 82.30.33.111 ( talk) 15:41, 27 April 2008 (UTC)
Photo caption: "City lights viewed in a motion blurred exposure. The AC blinking causes the lines to be dotted rather than continuous."
This should be considered highly suspect as most city lights are incandescent bulbs, which emit light through the relatively steady level of heat that builds up in a metal filament. The digital camera used to take the photo is a much more likely culprit. 71.244.17.134 ( talk) 14:57, 21 September 2008 (UTC)
Back to the original conversation, I do not see the point. Are you trying to say that the length of time it takes an incandescent light bulb to light up and to go dark is more than 1/60th of a second (or 1/50th of a second if the photo was taken in countries where the frequency is 50 Hz)? Mr. PIM ( talk) 23:07, 21 September 2008 (UTC)
It might be worth mentioning in this discussion that fluorescent and other lights with an almost instantaneous on/off brightness switch, flicker at twice the AC supply-frequency (because they light regardless of whether the AC voltage is positive or negative). So on a 50hz supply, they flicker at 100hz, and those countries with a 60hz supply have a 120hz flicker. PrinceGaz ( talk) 03:48, 11 February 2009 (UTC)
I removed the phase factor from "the power transmitted is equal to the product of the current, the voltage and the cosine of the phase difference φ ()" because it was not really relevant to the reason for high voltages in transmission, but it should be mentioned somewhere, with an explanation that the phase in question is that between V & I. Dbfirs 21:16, 22 November 2008 (UTC)
Hey, just added {{Unreferenced}} to article. I noticed there were no citations. Please add some. Thanks! 68.175.84.142 ( talk) 21:58, 27 January 2009 (UTC) (If you have any questions, please direct them to User:Riotrocket8676. Thanks!
I meant inline citations. Reclassified. 68.175.84.142 ( talk) 01:00, 2 February 2009 (UTC)
Due to the postion of the 'city lights' picture, there was a lot of white space, so I've moved it down, below the 'History' sub-heading, and slightly enlarged the default size of the 'Westinghouse Early AC System' diagram so they match.
This isn't ideal but I think it looks a lot better.
In a general observation, I find in the Wikipedia technical articles that a lot of pages have poor layout, and this makes them harder to read.
Ideally I believe all text should be aligned on the left margin and graphics generally on the right side, if they're not wide enough to be centred. -- 220.101.28.25 ( talk) 16:43, 31 October 2009 (UTC)
Please do not delete additions unless you are an expert in the subject. "Seems dubious" is not sufficient grounds for vandalism. But I will resist the temptation to play silly games until I have found a proper reference :) —Preceding unsigned comment added by 82.45.185.126 ( talk) 19:23, 1 March 2010 (UTC)
Might I ask someone to add a description of what 120/208, 277/480 refers to? I only understand single-phase, but I think it's phase-to-neutral (ground) versus phase-to-phase? Is WikiAnswers correct? [1] MrBell ( talk) 22:59, 22 April 2010 (UTC)
I added a link to Garyfallidou.org/en_electricity.html, a page containing a video which explains (to kids) how free electrons act in a simple circuit. In case of: No current, DC current and AC current. The link removed by Wtshymanski. I believe that Wikipedia (any encyclopedia) is for people (specially kids) who are trying to get knowledge and not for people who already have the Knowledge. The link added to Electric current-Direct Current-Alternating Current. Removed from Electric current - Alternating Current. Lambrosus —Preceding unsigned comment added by Lambrosus ( talk • contribs) 18:05, 26 May 2010 (UTC)
What is the reason for an AC circuit to have a neutral wire (0)? I mean the alternative current is passing through the consumator and returns usually 50 times per second (50HZ) but why it won't work if the signal don't return? Does the return signal contains an unused energy (like some watts which the consumator don't need)? Also if I touch a phase/line cable where AC or DC is applied and I am in air will the current hit me and in what situation? Or if I am on the ground but with a STRONG ISULATOR which don't allow current to pass through my body to the ground. As far as I know the current always needs a return path and if lets say 300 kilovolts and 100 ampers of current is applied will it do me something if it cannot return anywhere? Even if I am in space (vacuum)? :)))))))) =) -- Leonardo Da Vinci ( talk) 11:11, 1 December 2010 (UTC)
Although the voltage of a sinusoidal wave varies continuously with time, still we don't observe any change in the intensity of the visible light sources.Why? — Preceding unsigned comment added by 117.227.65.225 ( talk) 17:53, 30 June 2012 (UTC)
It appears that little is said about the role of the E and B fields of alternating current in this article. Furthermore, analysis reveals that
displacement current (based on time variations of the electric field) actually corresponds to the
jerk (physics) of electrons (based on time variations of force on each electron, as determined by the time-varying electric field). If sin(x) is the velocity in arbitrary units, then -sin(x), the second time derivative of sin(x), is jerk in arbitrary units, given that we set t'=1. As it turns out, for an alternating current system, the derivative of velocity, cos(x), and the derivative of jerk, -cos(x), cancel out exactly, meaning that their variations compensate for each other directly. Displacement current and electron current can be seen as flowing in opposite directions at a given point in an alternating current system. Please advise on the possibility on incorporating source material regarding E, B, D, H, P, and M fields in alternating circuits. Sincerely,
siNkarma86—Expert Sectioneer of Wikipedia
86 = 19+9+14 + karma = 19+9+14 +
talk
19:40, 7 April 2013 (UTC)
Commonname deals with article titles, not article content. And Charge is the term used when describing current, not current itself. -- Kyohyi ( talk) 17:05, 11 October 2013 (UTC)
1. The use of batteries for backup and load leveling. This needs a citation showing that batteries were used for this purpose in the days of early AC systems.
2. Direct-current generators could be easily paralleled. I don’t dispute that, but I’ve seen a technician bring an AC generator on line. You had to know what you were doing, but it was not hard. He had a phase meters and volt meters and there were three light bulbs for backup. Actually, he used the three light bulbs and then fine adjusted with the meters. This needs a citation saying that AC generators are harder to parallel than DC generators. Maybe the governors on the prime movers then less steady.
3. AC systems used series circuits for lighting with the attendant problems. No dispute there, but a citation is needed saying that DC systems worked differently. Constant314 ( talk) 23:19, 27 September 2014 (UTC)
I read the article and I didn't like it because it's not very well written. It is also somewhat unorganized. Most of all, I don’t like the order of the sections that make this article because they do not flow properly and they are not conducive to learning, especially for someone that does not know much about alternating current. Of top of it, I feel there are unnecessary disquisitions that lead to hard-to-understand concepts that are not that complicated.
Personally, I think this article should be reorganized: history should be first, mathematics second and transmission third. The discussions about frequency should be merged in a single section and could be placed between mathematics and transmission.
I have a few comments:
1. The sentence "This means that when transmitting a fixed power on a given wire, if the current is halved (i.e. the voltage is doubled), the power loss will be four times less." is not clear. It's clear that if current is halved power will be four times less but it's not clear to me how you can half the current by doubling the voltage if V=R*I. V and I are directly proportional. I think a clear explanation is required.
2. The expression "Mathematics of AC voltages" is a misnomer. There is no such thing as alternating current voltage but only alternating current or alternating voltage. This is somewhat awkward, even more when the article is about alternating current but the equations in it are for alternating voltage. There should be consistency.
3. The first equation under the section "Mathematics of AC voltages" only applies to sinusoidal functions. This is not stated explicitly so the statement cannot be considered true in general. The equation should use f(t) instead of sin(ωt).
4. The subsection entitled "Power oscillation" is not clear. I don't even know why it's there.
5. Something is wrong with "In their joint 1885 patent applications for novel transformers (later called ZBD transformers)". I think the sentence is missing a word between "for" and "novel" which is "their".
ICE77 ( talk) 03:04, 6 November 2016 (UTC)
Next to the figure of a single sinusoid cycle (1 crest followed by 1 trough of the curve), the text says "t is the time (unit: second)." The problem is that single cycles of alternating current are 60ths of a second, not seconds. Shouldn't it read "unit: 1/60 second"? The Mysterious El Willstro ( talk) 03:06, 6 May 2017 (UTC)
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Wikipedia is an encylopedia. This article is written for people who already know what Alternating Current is and how it is generated. The main article should be simpler and should explain to a common lay person, how alternating current is generated and functions. Advanced discussions should follow or be spun off to another article. And, no I can't be the one to fix it, I'm not qualified to explain the concept, I came to this article to firm up my own understanding. Gdewar ( talk) 21:21, 12 April 2008 (UTC)
I agree with Gdewar. The whole thing is rather uninformative, but I got really rankled when I came to
What I came to this article hoping to find out was: how the electrons move in the wire, what's happening at the power station to make them do that, something about hot and neutral, and what's the deal with the two different legs coming into my circuit box. And maybe something about how that back-and-forth electron motion is used to make appliances go. A good starting point for explanation may be to assume knowledge of DC, since that's simpler and easily understood by analogy to plumbing. The distinction between hot-and-neutral vs. negative-and-positive might also be worth a mention. Brock ( talk) 19:32, 19 November 2008 (UTC)
I'm not sure if this belongs here, but I know it isn't supposed to be part of the main article now. This is the simplest explanation of Three Phase Alternating Current I can come up with for you...
"The dynamos used to generate North American alternating current are designed to switch polarity 60 times a second, so they build a maximum voltage charge and drop it and then reverse the charge to a maximum negative voltage and drop it and so on, 60 times a second. This creates a high voltage current in the transmission line which reverses direction 60 times a second, saving the transmission line from amperage loads over long distances (electrons travelling in one direction the length of the transmission line will be found in Direct Current only, and they heat the wire easily) and result in high voltage without overheating the transmission line. Since there are down times, when the voltage drops and reverses polarity, it is more efficient to run three dynamos out of phase, and so transmit 180 voltage cycles a second, each of the three lines providing a voltage peak in sequence 60 times a second. Depending on how much power the customer requires, these 3 power lines are available, using transformers to lower the supplied voltage down to the minimum typical household voltage of 110 volts per line. Only two of those lines are delivered to the typical household, since being out of sequence the voltage differential between the positive and negative phases of the two 110 volt lines used to power your clothes dryer and stove will add up to a 220 volt differential for the heavy motors and resistors of the dryer and stove, which is why those 220 volt appliances are served by power from both sides of your circuit breaker panel (each side being connected to only one of the incoming 110 volt phase lines), while the rest of your appliances and lights will be served by only one line providing a single 110 volt cycle. The extra wire going to your appliances is the return to ground wire, which returns to your circuit breaker panel containing the voltage grounding line for the power lines in from the street (without grounding there is no voltage differential available to generate electron flow). This ground wire inside the circuit breaker panel is not the same thing as the ground wire in an appliance. The ground wire in an appliance, which you attach to a ground connection of your own choosing, such as the already wired-to-ground junction box in your wall, will simply divert stray electron flow away from your own body if the appliance short circuits and starts delivering stray electricity to the shell of the appliance, which you might touch." —Preceding unsigned comment added by 75.157.220.85 ( talk) 19:48, 22 November 2008 (UTC)
Here's something I wished was editted in.
(it should be edited into every relevant wiki page)
Can we get a practical world example and solve?
-So the theory was explained, and so was the equation for Power Loss. The power loss and power transmitted equations are identical so now I'm confused. With those equations being the same, then all power should be either lost entirely or transmitted entirely, so everything in AC current works and doesn't work at the same time. That isn't the case of course, I'm just not able to put the concepts into the practical world from the information listed on the wiki-page. Thanks (for future edits)! -- Viriality ( talk) 23:37, 18 October 2017 (UTC)
The common meaning of alternating current is for power distribution. The other referred to types are sometimes technically alternating current (and usually not). My edit trying to clarify the former was reverted as being awkward wording.......that could be true but we should try to work that common meaning clarification in. North8000 ( talk) 02:54, 24 January 2018 (UTC)
As an indicator of the general meaning of the term, I just googled "alternating current" and looked at the top 20 hits (not counting Wikipedia) and 100% only talked about power distribution. IMO this article gets too confusing by going off into the weeds of a lot of other specialized areas that are generally not called alternating current. And many of them (data transmission) described as AC are usually not AC, they are in essence one grounded conductor and another conductor with varying DC, and current flow is only in one direction. Sincerely, North8000 ( talk) 13:41, 24 January 2018 (UTC)
Granted, I'm not a scientist but I'm pretty sure that Tesla was very important in the history of AC yet he's only briefly mentioned once in the history section of this article. Does anyone with more knowledge on the subject think more about him should be added? — Preceding unsigned comment added by 2600:1700:69C1:2A00:79D6:BABB:C3E6:AE3C ( talk) 22:21, 4 July 2018 (UTC)
I think that the previous section is relevant to this. The common meaning of AC is power distribution, not other forms of signals which could technically be called AC but seldom have that term applied. And Tesla was quite prominent in that. North8000 ( talk) 12:42, 5 July 2018 (UTC)
I'm just throwing some thoughts out that might be helpful. I'm not going to worry about it much beyond that. That said, IMO saying "little influence on AC in the broadest sense" IMO is built on the false premise on the common use of the term that I was challenging. That said, IMO Tesla was very prominent in the history of AC power distribution primarily due to his prominence in the AC vs. DC battle. Sincerely, North8000 ( talk) 16:08, 6 July 2018 (UTC)
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The current in a 110 volt line pulses into the neutral line.
The current in the 220 and higher 3 phase lines pulses from multiple lead lines into the neutral line.
All the current travels from the lead line into the neutral line.
To prove this DIODES are used to convert AC into DC.
— Preceding unsigned comment added by 108.89.36.16 ( talk) 01:02, 27 January 2014 (UTC)
References
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I was going to put that unlike DC, AC does not need to return to its source, as it can flow to ground. However, I may be wrong on two counts... Can DC flow to ground as AC can? And also, am I wrong about AC somehow? I think I'm confused... —Preceding unsigned comment added by ReignMan ( talk • contribs) 11:01, 1 December 2007
The AC or DC can flow to ground, if you connect one terminal of a DC supply to ground then you can supply a load via the other terminal of the DC source and return it to ground. The reason AC tpically does this is that "ground" is established at the generation plant and at the customer premises.
Remember the electrons don;t care if they always go the same way or if every so often they reverse direction, so AC and DC behave the exact same way in a lot a respects, like when discussing grounds.
This article also states that the since wave is the most efficient form of energy transfer - this is not the "real" reason AC is sinewave. Sinvewaves are what you get when you have a rotating magnetic field (e.g. in an alternator) - it is quite hard to generate a triangle or sawtooth or square wave mechanically as it requires rapid cahnges in direction. Technically this means the sine is more efficient but it's a bad way to state it. —Preceding unsigned comment added by 60.234.222.212 ( talk) 06:52, 14 October 2008 (UTC)
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
Why is this discussion done in terms of voltage? I realize that ac voltage often accompanies ac current, but seeing as how this is an article about ac current it seems better to just stick to ac current. The math won't be any different, so I just don't see the reason to switch to voltage for calculations. —Preceding unsigned comment added by 146.115.120.149 ( talk) 20:18, 20 September 2006
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
Just wondering if anyone else finds it confusing that the multiplication sign is an 'X', the symbol for cross product. I realize that this or a dot are often used, but with the inclusion of the sine function in the equation already it may be misleading. -- Bmalicoat 23:47, 26 October 2005 (UTC)
The wording "His design was a primitive precursor of the modern transformer, called an induction coil" is not very NPOV.
I'd like to see some pictures of AC in action words can't describe it well enough. -- Cyberman 02:30, 10 Feb 2005 (UTC)
I think this page is nice. Congratulations to those who've been working on it. I nominated it for featured articles. A picture would be nice, though. Power cables, transformers or something. Washington Irving | Talk 23:21, 25 Mar 2004 (UTC)
I could write a part about transforming DC->AC through a solenoid- condensator circuit and a triode. Anyone think this is useful and/or fitting here?
-
Xorx77 17:09, 28 Mar 2004 (UTC)
I changed the usual Teslaphile stuff to give due credit to some of the other critical workers in the field. Look guys, I know you venerate the guy, but the reality is that his contribution to the field, although undoubtedly important, was just one aspect of many advances in electrical engineering at the time. In particular, describing him as the father or inventor of AC makes a good book blurb but is totally unsupportable. Among the critical parts of the infrastructure he didn't invent were: transformers, the AC distribution system, AC generators, or meters. His major practical contribution was AC motors - and the first one he ever built that actually worked, was under contract to Westinghouse. Securiger 13:18, 21 Jun 2004 (UTC)
Actually the Tesla coil is an 'air core' power transformer: http://en.wikipedia.org/wiki/Tesla_coil. The historical sections of this article are a POV mess and require serious re-writing. Counterinduction. 09.33, 15/4/2014 (GMT)
— Preceding unsigned comment added by 129.234.252.66 ( talk) 08:34, 15 April 2014 (UTC)
I updated the sections on power and 3 phase systems, which are hopefully a bit clearer now. Also the section on earths and neutrals which had become a little muddled. The earth is not the same as a neutral. A neutral is used to form a complete circuit in a healthy system, an earth is used to provide a specified path for current during a fault. —Preceding unsigned comment added by 62.172.213.132 ( talk) 15:32, 23 September 2004
Did the guy who wrote this ever actually stick the probes of an oscilloscope into the wall outlet? —Preceding unsigned comment added by Rsduhamel ( talk • contribs) 21:21, 27 December 2004
The article currently has a lot of stuff that is covered in other articles; three phase, grounding, etc. I think the discussion here could be compacted since details are only a mouse-click away. I also cleared up some leading spaces in the talk page - not everyone is signing contributions - use the button for signatures in the editor or else manually put --~~~~ at the end of your comments. -- Wtshymanski 17:26, 1 Jun 2005 (UTC)
I consider the concepts of electrical current/voltage, resistance/reactance and power to be sufficiently different that they should not be merged, otherwise the combined article will become too long and very difficult to organize clearly. I note that there is inadequate discussion in these articles of non-sinusoidal waveforms, particularly of the substantial 3rd and 5th harmonics generated by the non-linearity of standard power transformers - that would make a combined article even longer. Then there are the square and 2-step waveforms of DC-AC power converters. I recommend keeping these three separate but consistent, with appropriate cross links. As a retired electrical engineer, I could try to start this process, but would do so only when agreement is reached on separation. JohnSankey 15:31, 5 October 2005 (UTC)
Can we remove some of the merge templates then?-- John 23:45, 16 October 2005 (UTC)
Just to note that "mains power" is a British term. I have never heard it used in North America. JohnSankey 22:59, 5 October 2005 (UTC)
Why do these articles simply redirect to this article, when this article makes no mention of them? —Preceding unsigned comment added by 62.56.57.235 ( talk) 10:45, 17 October 2005
I am sorry if I sound negative, but this article/entry (Alternating current) is un-organized, and even though it's extraordinarely short for such an important and vast subject, it feels too long to read.
The consequences of the bad architecture of the entry, is that even contributors have trouble striking the right balance when trying to add relevant information. For example, Nikola Tesla is under-represented, even though he has almost single-handidly produced virtually all the elements of the puzzle necessary for the AC power system (I won't spend time documenting this point, if anyone thinks it's open to dispute, I'm willing). I don't blame it on anyone's agenda, but simply, on the fact that the article is discouraging of contribution. I have tried, anonymously, to correct few of the more evident errors, and am preparing to beef up the body on Steinmetz and Tesla. Still, every time I think of this wikipedia entry, I feel pain in my stomach, so I keep putting off the big work for another day. Old-fool 17:56, 21 October 2005 (UTC)
I don't know what you mean by power lost = I^2 * R. This is supposed to be the equation for power transmitted, and since V=I*R, power = V*I also. Therefore, I don't see why the power equation explains why current affects power lost and not voltage. Can someone clarify this please? —Preceding unsigned comment added by 24.184.127.141 ( talk) 03:47, 3 November 2005
I think you should explain it since the present simplicity is deceptive and also confusing due to the question of why I should think about I^2 * R instead of V^2/R. —Preceding unsigned comment added by Jcline1 ( talk • contribs) 13:39, 26 November 2007 (UTC)
I would suggest that you read Wikipedia articles on alternating current and direct current. Nikola 22:54, 28 November 2005 (UTC)
This is a shockingly sparse and badly organised article considering the importance of AC power in the world. —Preceding unsigned comment added by 148.197.54.206 ( talk) 15:12, 1 December 2005
Volt-amp redirects to this article, but I don't see any mention of it here. In particular, I'd like to know how volt-amps are related to watts. (I thought were the same, but then why is a UPS I'm looking at rated at "500VA" but "300W"?) - dcljr ( talk) 04:50, 16 January 2006 (UTC)
“ | It is generally accepted that Nikola Tesla chose 60 hertz as the lowest frequency that would not cause street lighting to flicker visibly. The origin of the 50 hertz frequency used in other parts of the world is open to debate but seems likely to be a rounding off of 60 Hz to the 1-2-5-10 structure, called a set of preferred numbers, popular with metric standards | ” |
What other parts of the world? I assume other than the U.S.A. If you take a look at the frequencies used you will notice that 50 hertz is the most commonly used frequecy , with a few (but major) exceptions (mainly North America). It's a minor issue of how you put it , since I don't think all users of wikipedia regard this from the point of view of an american as we can't be all americans :)) —Preceding unsigned comment added by 82.76.35.22 ( talk) 07:36, 31 January 2006
See my comment above. I'm deleting the following passage and replacing it. Included here in case someone wants to rollback or merge. -- Psm 20:27, 1 August 2006 (UTC)
It is generally accepted that [[Nikola Tesla]] chose 60 [[hertz]] as the lowest frequency that would not cause street lighting to flicker visibly. The origin of the 50 hertz frequency used in other parts of the world is open to debate but seems likely to be a rounding off of 60 Hz to the 1-2-5-10 structure, called a set of [[preferred number]]s, popular with metric standards.
60Hz may also have been chosen as it would make for more convinent gearing ratios in electric clocks. A synchronus motor runing on 60Hz rotates at 3600rpm (or a submultiple therof) 3600 rpm through a 60:1 gear ratio is 60rpm (i.e. 1 rev/sec) with succesive 60:1 gear ratios giving 1 rev/min (for the second hand) and 1 rev/hour (for the minute hand) 87.113.7.148 17:48, 12 August 2006 (UTC)
The only difference between AC and DC is that AC alternate between positive and negative values as DC always stay positive...You can have a perfect sine wave which stay on positive values as a DC current. So the form of the wave as nothing to do with DC or AC. You can also have pulsed waves that can be AC. Magnitude have nothing to do here... —Preceding unsigned comment added by 65.92.142.247 ( talk) 22:48, 10 February 2006
When you are mixing two currents it's sure you can't tell at this moment whether its DC or AC because its both but usually the DC will be use to transport AC and then be divided again by a coil and/or capacitors. The result will be a positive sine-wave and a alternating sine-wave. —Preceding
unsigned comment added by
65.93.158.199 (
talk) 23:28, 22 March 2006
I forgot most of what i know of AC's history, but im pretty sure Edison hated it... I don't really remember, so I came here. I am dissappointed to find that this info isn't here, so I'll have to look elsewhere for now! Maybe I'll do some research and write it myself if I have time. —Preceding unsigned comment added by 74.130.112.57 ( talk) 01:42, 29 July 2006
I think this article needs a section on how the alternating current is generated and one on how direct current can be transformed into alternating current. —The preceding unsigned comment was added by 193.226.140.133 ( talk • contribs) .
I wanted to know exactly what happens with the three holes in an outlet. Since voltage is a difference, and a circuit must be closed to receive it, does only one of the leads vary, or both, in opposite phases from each other? If the latter, does that mean connecting the same terminal from two different outlets produces no current? If the former, does that mean one of the terminals has no power? Does the ground terminal connect directly to the ground or a building's structure, as opposed to running through a power cable? Badmuthahubbard 20:33, 19 August 2006 (UTC)
You have twisted pair but what about the twin lead we used to use for TV antennas? Some people used forms of twin lead for ham radio. Knob and tube and romex could be concidered twin lead as well. -- Gbleem 13:54, 2 September 2006 (UTC)
The article makes no mention of who first developed (or experimented with) the theory of alternating current...—Preceding unsigned comment added by 219.88.179.132 ( talk) 11:29, 7 September 2006
does alternating current have positive and negitive like direct current?-- Falcon866 02:35, 5 January 2007 (UTC)
The article on DC has an image showing the DC "symbol" that is used on electronics and such. I would assume there is a corresponding symbol for AC. I think it would be a good addition for the article to contrast it with DC. - AndrewBuck 22:49, 27 March 2007 (UTC)
Here on the Wikipedia, where a dozen articles go into great and varying detail on the standardization of European utilization voltages, we (used to ) find the light-hearted statement that American utilization voltage is 3 phase 110 volts. Sorry, it's not - not three phase, and not 110 volts. You won't find a reference for this because it doesn't exist. I've taken it out again, it's not relevant to the example. There's no salvaging the commented-out paragraph and I recommend it be deleted. -- Wtshymanski 21:13, 10 April 2007 (UTC)
The equation Vrms=Vpeak is only true if centered about the x-axis. If a dc-offset is considered the equation is invalid. Duty cycle must then be taken into account. Consider a square wave with 50 percent duty cycle, peak voltage of 1 volt, centered at half a volt. Rms voltage is then 0.707... Someone tell me I have had too much coffee tonight, and that I am in error. —Preceding unsigned comment added by 24.9.208.230 ( talk) 04:37, 30 November 2007 (UTC)
Why doesn't this article say which is battery power and which is wall-plug power. I always forget. I can't be the only one can I? —Preceding unsigned comment added by 81.138.12.194 ( talk) 11:13, 1 February 2008 (UTC)
The date of the first modern A/C station is wrong. The first such station was built by Ferranti at Deptford near London in 1891. It produced an A/C 10Kv supply, with transforner stations for each street served. Chasnor15 ( talk) 11:12, 28 March 2008 (UTC)
"HVDC systems tend to be more expensive and less efficient than transformers." This statement is wrong (or at least needs some justification), otherwise why would they use HVDC. HVDC systems can be more efficient at transporting large quantities of power, as there is no reactive power. The efficiency of the power electronics is increasing annually as new GTO's/IGBT's are developed. —Preceding unsigned comment added by 82.30.33.111 ( talk) 15:41, 27 April 2008 (UTC)
Photo caption: "City lights viewed in a motion blurred exposure. The AC blinking causes the lines to be dotted rather than continuous."
This should be considered highly suspect as most city lights are incandescent bulbs, which emit light through the relatively steady level of heat that builds up in a metal filament. The digital camera used to take the photo is a much more likely culprit. 71.244.17.134 ( talk) 14:57, 21 September 2008 (UTC)
Back to the original conversation, I do not see the point. Are you trying to say that the length of time it takes an incandescent light bulb to light up and to go dark is more than 1/60th of a second (or 1/50th of a second if the photo was taken in countries where the frequency is 50 Hz)? Mr. PIM ( talk) 23:07, 21 September 2008 (UTC)
It might be worth mentioning in this discussion that fluorescent and other lights with an almost instantaneous on/off brightness switch, flicker at twice the AC supply-frequency (because they light regardless of whether the AC voltage is positive or negative). So on a 50hz supply, they flicker at 100hz, and those countries with a 60hz supply have a 120hz flicker. PrinceGaz ( talk) 03:48, 11 February 2009 (UTC)
I removed the phase factor from "the power transmitted is equal to the product of the current, the voltage and the cosine of the phase difference φ ()" because it was not really relevant to the reason for high voltages in transmission, but it should be mentioned somewhere, with an explanation that the phase in question is that between V & I. Dbfirs 21:16, 22 November 2008 (UTC)
Hey, just added {{Unreferenced}} to article. I noticed there were no citations. Please add some. Thanks! 68.175.84.142 ( talk) 21:58, 27 January 2009 (UTC) (If you have any questions, please direct them to User:Riotrocket8676. Thanks!
I meant inline citations. Reclassified. 68.175.84.142 ( talk) 01:00, 2 February 2009 (UTC)
Due to the postion of the 'city lights' picture, there was a lot of white space, so I've moved it down, below the 'History' sub-heading, and slightly enlarged the default size of the 'Westinghouse Early AC System' diagram so they match.
This isn't ideal but I think it looks a lot better.
In a general observation, I find in the Wikipedia technical articles that a lot of pages have poor layout, and this makes them harder to read.
Ideally I believe all text should be aligned on the left margin and graphics generally on the right side, if they're not wide enough to be centred. -- 220.101.28.25 ( talk) 16:43, 31 October 2009 (UTC)
Please do not delete additions unless you are an expert in the subject. "Seems dubious" is not sufficient grounds for vandalism. But I will resist the temptation to play silly games until I have found a proper reference :) —Preceding unsigned comment added by 82.45.185.126 ( talk) 19:23, 1 March 2010 (UTC)
Might I ask someone to add a description of what 120/208, 277/480 refers to? I only understand single-phase, but I think it's phase-to-neutral (ground) versus phase-to-phase? Is WikiAnswers correct? [1] MrBell ( talk) 22:59, 22 April 2010 (UTC)
I added a link to Garyfallidou.org/en_electricity.html, a page containing a video which explains (to kids) how free electrons act in a simple circuit. In case of: No current, DC current and AC current. The link removed by Wtshymanski. I believe that Wikipedia (any encyclopedia) is for people (specially kids) who are trying to get knowledge and not for people who already have the Knowledge. The link added to Electric current-Direct Current-Alternating Current. Removed from Electric current - Alternating Current. Lambrosus —Preceding unsigned comment added by Lambrosus ( talk • contribs) 18:05, 26 May 2010 (UTC)
What is the reason for an AC circuit to have a neutral wire (0)? I mean the alternative current is passing through the consumator and returns usually 50 times per second (50HZ) but why it won't work if the signal don't return? Does the return signal contains an unused energy (like some watts which the consumator don't need)? Also if I touch a phase/line cable where AC or DC is applied and I am in air will the current hit me and in what situation? Or if I am on the ground but with a STRONG ISULATOR which don't allow current to pass through my body to the ground. As far as I know the current always needs a return path and if lets say 300 kilovolts and 100 ampers of current is applied will it do me something if it cannot return anywhere? Even if I am in space (vacuum)? :)))))))) =) -- Leonardo Da Vinci ( talk) 11:11, 1 December 2010 (UTC)
Although the voltage of a sinusoidal wave varies continuously with time, still we don't observe any change in the intensity of the visible light sources.Why? — Preceding unsigned comment added by 117.227.65.225 ( talk) 17:53, 30 June 2012 (UTC)
It appears that little is said about the role of the E and B fields of alternating current in this article. Furthermore, analysis reveals that
displacement current (based on time variations of the electric field) actually corresponds to the
jerk (physics) of electrons (based on time variations of force on each electron, as determined by the time-varying electric field). If sin(x) is the velocity in arbitrary units, then -sin(x), the second time derivative of sin(x), is jerk in arbitrary units, given that we set t'=1. As it turns out, for an alternating current system, the derivative of velocity, cos(x), and the derivative of jerk, -cos(x), cancel out exactly, meaning that their variations compensate for each other directly. Displacement current and electron current can be seen as flowing in opposite directions at a given point in an alternating current system. Please advise on the possibility on incorporating source material regarding E, B, D, H, P, and M fields in alternating circuits. Sincerely,
siNkarma86—Expert Sectioneer of Wikipedia
86 = 19+9+14 + karma = 19+9+14 +
talk
19:40, 7 April 2013 (UTC)
Commonname deals with article titles, not article content. And Charge is the term used when describing current, not current itself. -- Kyohyi ( talk) 17:05, 11 October 2013 (UTC)
1. The use of batteries for backup and load leveling. This needs a citation showing that batteries were used for this purpose in the days of early AC systems.
2. Direct-current generators could be easily paralleled. I don’t dispute that, but I’ve seen a technician bring an AC generator on line. You had to know what you were doing, but it was not hard. He had a phase meters and volt meters and there were three light bulbs for backup. Actually, he used the three light bulbs and then fine adjusted with the meters. This needs a citation saying that AC generators are harder to parallel than DC generators. Maybe the governors on the prime movers then less steady.
3. AC systems used series circuits for lighting with the attendant problems. No dispute there, but a citation is needed saying that DC systems worked differently. Constant314 ( talk) 23:19, 27 September 2014 (UTC)
I read the article and I didn't like it because it's not very well written. It is also somewhat unorganized. Most of all, I don’t like the order of the sections that make this article because they do not flow properly and they are not conducive to learning, especially for someone that does not know much about alternating current. Of top of it, I feel there are unnecessary disquisitions that lead to hard-to-understand concepts that are not that complicated.
Personally, I think this article should be reorganized: history should be first, mathematics second and transmission third. The discussions about frequency should be merged in a single section and could be placed between mathematics and transmission.
I have a few comments:
1. The sentence "This means that when transmitting a fixed power on a given wire, if the current is halved (i.e. the voltage is doubled), the power loss will be four times less." is not clear. It's clear that if current is halved power will be four times less but it's not clear to me how you can half the current by doubling the voltage if V=R*I. V and I are directly proportional. I think a clear explanation is required.
2. The expression "Mathematics of AC voltages" is a misnomer. There is no such thing as alternating current voltage but only alternating current or alternating voltage. This is somewhat awkward, even more when the article is about alternating current but the equations in it are for alternating voltage. There should be consistency.
3. The first equation under the section "Mathematics of AC voltages" only applies to sinusoidal functions. This is not stated explicitly so the statement cannot be considered true in general. The equation should use f(t) instead of sin(ωt).
4. The subsection entitled "Power oscillation" is not clear. I don't even know why it's there.
5. Something is wrong with "In their joint 1885 patent applications for novel transformers (later called ZBD transformers)". I think the sentence is missing a word between "for" and "novel" which is "their".
ICE77 ( talk) 03:04, 6 November 2016 (UTC)
Next to the figure of a single sinusoid cycle (1 crest followed by 1 trough of the curve), the text says "t is the time (unit: second)." The problem is that single cycles of alternating current are 60ths of a second, not seconds. Shouldn't it read "unit: 1/60 second"? The Mysterious El Willstro ( talk) 03:06, 6 May 2017 (UTC)
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Wikipedia is an encylopedia. This article is written for people who already know what Alternating Current is and how it is generated. The main article should be simpler and should explain to a common lay person, how alternating current is generated and functions. Advanced discussions should follow or be spun off to another article. And, no I can't be the one to fix it, I'm not qualified to explain the concept, I came to this article to firm up my own understanding. Gdewar ( talk) 21:21, 12 April 2008 (UTC)
I agree with Gdewar. The whole thing is rather uninformative, but I got really rankled when I came to
What I came to this article hoping to find out was: how the electrons move in the wire, what's happening at the power station to make them do that, something about hot and neutral, and what's the deal with the two different legs coming into my circuit box. And maybe something about how that back-and-forth electron motion is used to make appliances go. A good starting point for explanation may be to assume knowledge of DC, since that's simpler and easily understood by analogy to plumbing. The distinction between hot-and-neutral vs. negative-and-positive might also be worth a mention. Brock ( talk) 19:32, 19 November 2008 (UTC)
I'm not sure if this belongs here, but I know it isn't supposed to be part of the main article now. This is the simplest explanation of Three Phase Alternating Current I can come up with for you...
"The dynamos used to generate North American alternating current are designed to switch polarity 60 times a second, so they build a maximum voltage charge and drop it and then reverse the charge to a maximum negative voltage and drop it and so on, 60 times a second. This creates a high voltage current in the transmission line which reverses direction 60 times a second, saving the transmission line from amperage loads over long distances (electrons travelling in one direction the length of the transmission line will be found in Direct Current only, and they heat the wire easily) and result in high voltage without overheating the transmission line. Since there are down times, when the voltage drops and reverses polarity, it is more efficient to run three dynamos out of phase, and so transmit 180 voltage cycles a second, each of the three lines providing a voltage peak in sequence 60 times a second. Depending on how much power the customer requires, these 3 power lines are available, using transformers to lower the supplied voltage down to the minimum typical household voltage of 110 volts per line. Only two of those lines are delivered to the typical household, since being out of sequence the voltage differential between the positive and negative phases of the two 110 volt lines used to power your clothes dryer and stove will add up to a 220 volt differential for the heavy motors and resistors of the dryer and stove, which is why those 220 volt appliances are served by power from both sides of your circuit breaker panel (each side being connected to only one of the incoming 110 volt phase lines), while the rest of your appliances and lights will be served by only one line providing a single 110 volt cycle. The extra wire going to your appliances is the return to ground wire, which returns to your circuit breaker panel containing the voltage grounding line for the power lines in from the street (without grounding there is no voltage differential available to generate electron flow). This ground wire inside the circuit breaker panel is not the same thing as the ground wire in an appliance. The ground wire in an appliance, which you attach to a ground connection of your own choosing, such as the already wired-to-ground junction box in your wall, will simply divert stray electron flow away from your own body if the appliance short circuits and starts delivering stray electricity to the shell of the appliance, which you might touch." —Preceding unsigned comment added by 75.157.220.85 ( talk) 19:48, 22 November 2008 (UTC)
Here's something I wished was editted in.
(it should be edited into every relevant wiki page)
Can we get a practical world example and solve?
-So the theory was explained, and so was the equation for Power Loss. The power loss and power transmitted equations are identical so now I'm confused. With those equations being the same, then all power should be either lost entirely or transmitted entirely, so everything in AC current works and doesn't work at the same time. That isn't the case of course, I'm just not able to put the concepts into the practical world from the information listed on the wiki-page. Thanks (for future edits)! -- Viriality ( talk) 23:37, 18 October 2017 (UTC)
The common meaning of alternating current is for power distribution. The other referred to types are sometimes technically alternating current (and usually not). My edit trying to clarify the former was reverted as being awkward wording.......that could be true but we should try to work that common meaning clarification in. North8000 ( talk) 02:54, 24 January 2018 (UTC)
As an indicator of the general meaning of the term, I just googled "alternating current" and looked at the top 20 hits (not counting Wikipedia) and 100% only talked about power distribution. IMO this article gets too confusing by going off into the weeds of a lot of other specialized areas that are generally not called alternating current. And many of them (data transmission) described as AC are usually not AC, they are in essence one grounded conductor and another conductor with varying DC, and current flow is only in one direction. Sincerely, North8000 ( talk) 13:41, 24 January 2018 (UTC)
Granted, I'm not a scientist but I'm pretty sure that Tesla was very important in the history of AC yet he's only briefly mentioned once in the history section of this article. Does anyone with more knowledge on the subject think more about him should be added? — Preceding unsigned comment added by 2600:1700:69C1:2A00:79D6:BABB:C3E6:AE3C ( talk) 22:21, 4 July 2018 (UTC)
I think that the previous section is relevant to this. The common meaning of AC is power distribution, not other forms of signals which could technically be called AC but seldom have that term applied. And Tesla was quite prominent in that. North8000 ( talk) 12:42, 5 July 2018 (UTC)
I'm just throwing some thoughts out that might be helpful. I'm not going to worry about it much beyond that. That said, IMO saying "little influence on AC in the broadest sense" IMO is built on the false premise on the common use of the term that I was challenging. That said, IMO Tesla was very prominent in the history of AC power distribution primarily due to his prominence in the AC vs. DC battle. Sincerely, North8000 ( talk) 16:08, 6 July 2018 (UTC)
A discussion is taking place to address the redirect
Effective power. The discussion will occur at
Wikipedia:Redirects for discussion/Log/2021 July 8#Effective power until a consensus is reached, and readers of this page are welcome to contribute to the discussion. --
Tamzin (she/they) |
o toki tawa mi.
12:54, 8 July 2021 (UTC)