Jump to content

Talk:Electric spark

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

Merging in Electrostatic Discharge

[edit]

This page tends to talk in generalities and gives examples of how an electric spark can be used. An "electric spark" in the sense it is used here is simply an "electrostatic discharge", which is for the most part what a spark is... electric field potential exceeding the threshold of the insulation between the opposite charges and jumping the gap to equalize. The electrostatic discharge page does a much better job explaining the phenomena, and "electric spark" could easily be incorporated into it. That page may be better served by renaming "Spark", and moving ESD in the application of electronics to a subcategory, not the primary. Searches for ESD should then go to that page, or an "also known as" added at the top. Another "electric discharge" used interchangeably for consideration.... Electrical_discharge. Thoughts, comments.... Borealdreams (talk) 22:29, 13 March 2012 (UTC)[reply]

I agree that a section on theory should be added and the article expanded beyond C class, perhaps by expanding on the material in the electrostatic discharge article. But since a spark is only one type of electrostatic discharge, a merge isn't appropriate. --Kkmurray (talk) 21:53, 14 March 2012 (UTC)[reply]
Oppose as well. There are multiple kinds of electrostatic discharge and this article also covers a wide range of things in regards to electric sparks. It's best to keep them separate. SilverserenC 22:34, 14 March 2012 (UTC)[reply]

I guess I am just trying to find the best way to get all these pages in agreement with one another, instead of different messages & links to different sources. They are all essentially the same thing, the threshold being reached of an insulation medium for the neutralization of an electric potential across that medium. Whether it is "natural-static caused" or "human-caused (ie spark plug), it is still the same end result a Spark. Suggestions on how to do so? Borealdreams (talk) 17:14, 15 March 2012 (UTC)[reply]

In spectroscopy and chemical analysis, the discharge type is extremely important. I would suggest first expanding the articles and as they approach good status their overall organization should become more apparent. --Kkmurray (talk) 13:49, 16 March 2012 (UTC)[reply]

Request for merge into Electric arc

[edit]

Electric Spark and Electric Arc are the same thing (So-far I know). So I suggest to merge the content (Photographs and text-informations) into the page Electric Arc, since the page on Electric Arc contains more technical informations.

Oppose. They're not the same thing. They are a similar thing, but the scales are different. There is a whole taxonomy of electrical discharges, categorized according to the energy involved. Andy Dingley (talk) 09:30, 10 June 2016 (UTC)[reply]
I have to agree very much with Andy here. This article looks like it could use a substantial amount of work. In short, a spark is only a distinct part of an electrical discharge. A lightning bolt, for example, is preceded by a spark, but the the main part of the discharge is an arc.
The book The Mechanism of the Electric Spark, by Leonard Benedict Loeb and John M. Meek, under the Townsend scheme defines a spark as follows: "The spark is an unstable, irreversible, and transient phenomenon sometimes marking the transition from one more or less stable condition of current between electrodes in a gas to another more stable one under imposed conditions." In other words, before a lightning bolt strikes, there is ionization of the air around both the positive electrode (the clouds or air) and the negative electrode (the ground). This is only a partially stable state, because the ions begin forming long chains called "spark streamers". (This is why people who are struck by lightning often report feeling their hair stand on end just prior to the strike.) When a streamer forms, it quickly grows up or downward (depending on polarity) at just over 100 miles per second. As soon as it contacts either a streamer of opposite polarity or the opposite electrode, the spark forms. The spark remains unstable, because as current increases the voltage and resistance decrease, (drawing more current), and this continues until the discharge reaches an equilibrium. (For an arc, the voltage will drop to some percentage of the square-root of current, depending on impedance.) When this happens, the lightning bolt is an arc and the discharge remains stable until the remainder of the energy is spent.
A good visualization of how this works can be seen in the animation at the end of the flashtube article (lightning in a bottle). A glow discharge is characterized by a relatively high-voltage, cold-cathode emission of electrons, while an arc by the thermionic emission of electrons. The spark is the transient state between the off state and one of these other two states, or an unstable transition from glow to arc. Nearly every discharge begins with a spark. When the energy is low enough most of it may be used just heating the gas, in which case the spark never fully develops and stabilizes into a glow or arc, which is what people commonly think of as a spark in, say, a static shock or stun-gun.Zaereth (talk) 01:51, 10 May 2017 (UTC)[reply]
I might add that a lightning bolt tends to be extremely underdamped as far as discharges go, and are often prone to ringing. (In a high-speed photographic animation, you may see what appears to be 30 or 40 strikes from one bolt, but this really tends to be the ringing back and forth.) Zaereth (talk) 21:03, 10 May 2017 (UTC)[reply]

Welding photo

[edit]

I'm not sure the welding photo is the best example for this article. It's great for the welding article and a very good photo, but the weld itself is done by an arc, not a spark. The sparks flying away from the weld are not electrical but rather bits of molten or burning metal, which is a totally different kind of spark. (More related to sparks from a grinder than electric sparks.)

I went ahead and changed it to a photo of a stun gun, as in this one you can really see the spark. Zaereth (talk) 21:24, 5 October 2017 (UTC)[reply]

History

[edit]

Lots of issues with the history section. For the moment, I've merely amended the part about Dailibard's involvement. I will return at some later point to add other information about earlier experiments. Surprised to see Leibniz mentioned here -- he seems rather an odd outlier, certain never mentioned in the major historiography on early electricity such as Helibron's classic tome [1] and while an earlier editor cites Heilbron with regard to Ward, where are du Fay and Stephen Gray, whose work is certainly of far greater significance?; Karxpava (talk) 19:04, 23 October 2017 (UTC)[reply]

References

  1. ^ Heilbron, Electricity in the 17th and 18th Centuries: A Study of Early Modern Physics. University of California Press

Contradiction with the Taser page

[edit]

According to https://en.wikipedia.org/wiki/Taser?wprov=sfla1, tasers produce an arc, not a spark like this page suggests. I'm completely neutral on this matter because I don't know which is true and I was looking on Wikipedia to find out more, but came across said contradiction. I have brought up this issue in Taser's discussion section, too, and have provided the link of this page there. I would greatly appreciate for this to be resolved. Reployer (talk) 07:27, 20 March 2021 (UTC)[reply]

The taser page is wrong. An arc is a high current, low voltage, electrical discharge. Arcs are characterized by thermionic emission of electrons from the cathode, meaning the electrode needs to be extremely hot for an arc to form. Arcs are great for welding due to the high current and extremely high temperatures, but that type of current level will cause serious burns and is incredibly likely to damage the heart and internal organs. Typically, it only takes a few milliamps across the heart to shut it down.
in contrast, the spark from a taser or a stun gun is extremely high voltage and extremely low current. The electrodes remain cold, and the spark rarely if ever causes burns. Current is kept extremely low to help prevent the chance of causing death or serious burns, not to mention extending battery life. (For an arc, you'd need something more like a car battery). The spark is not hot (by arc standards), will not burn you, you can't weld or cut with it. All it does is flood your own nervous system with a high-voltage signal, causing your muscles to involuntarily contract. It feels like getting kicked by a mule, but ultimately leaves no physical damage other than some sore muscles.
Along that same vein (no pun intended), the high voltage of a spark is more likely to follow the conductive pathways of the nerves, whereas the high current from an arc will usually follow the higher conductivity of the arteries. I remember once, this kid got a job at one of the local power plants. Like an idiot, he tried to stash some weed behind a big safety panel housing some really huge, copper buses. When his baggie fell back behind, he reached in to feel around for it. The electricity went in through his hand and came out his leg in two places. He survived, barely, but suffered extensive third-degree burns to his arteries. It boiled his blood, and the doctors had to splay his arteries open, from his hand to his foot, scrape away all the charred material, and to this day he has never fully recovered. Arcs cause real damage and are not something you want to mess with. Zaereth (talk) 12:23, 20 March 2021 (UTC)[reply]

Cool. Thanks for letting me know. I personally find the terminology a bit weird, but I'm not the one who made it up, so it's good to be on the same page as others. Be advised that I've now suggested an edit to that page, but it's my first edit on Wikipedia, so I don't know if I did it properly. Reployer (talk) 06:47, 21 March 2021 (UTC)[reply]

Your edit is fine, but I would suggest using ctrl+F and make sure you got them all. I see a couple more down below. Note that these are sourced to a manufacturer's website, and that's a bit too much like advertising and we don't allow that on Wikipedia, so I would suggest just deleting the entire section per WP:PROMOTION. Manufactures like to really oversell their products, and "arc" sounds more bad ass than spark, but that why we don't use those as reliable sources.
Electricity can be really confusing. For one thing, in the air it has negative resistance, meaning as the discharge gets hotter, both the resistance and voltage drop like a rock. It's backwards. See the chart to the right. See how it transitions to an arc right at one amp? The spark is what happens between A and B, although a different kind of spark also occurs between H and I. We call this an unstable transition from one more-or-less stable state (the off state) another, more stable state (a glow discharge or an electric arc), with the arc being the most stable. What the taser does is still between A and B on the graph, and nowhere near a glow or an arc. However, it's that instability that makes it work. Manufacturers call it a "modulated" current, but what that means is it's an interrupted DC current, or, in other words, it just keeps sparking rapidly, over and over (and every time it's like getting kicked by a mule again). I hope that helps clear up some of the weirdness. Zaereth (talk) 07:30, 21 March 2021 (UTC)[reply]