I might be wrong, but i believe tantalum caps are polarized, but not electrolytic. The original sulphuric acid filled tantalums would have been, however i understand from my 10 second search that the normal, current ones might not qualify. —Preceding unsigned comment added by 121.214.192.24 (talk) 08:48, 2 December 2010 (UTC)
So in what direction should i put a electrolytic capacitor in my electric circuit? minus on plus? or minus on ground? thanks, --Abdull 16:15, 6 Dec 2004 (UTC)
I don't think much of the extended discussion of safety precautions for handling electrolyte leaks. I think that's of questionable relevance and value. I'm also dubious about some of the factual information in that passage - I already removed one howler (about tantalum capacitors being military-only) which looks like the information may be about 20 years out of date, and I suspect other nearby statements may be incorrect also. I think at some point in the future I'll probably delete that stuff, or move it to some other page. Not sure where yet, which is why I haven't done so already.129.97.79.144 21:05, 2 Jun 2005 (UTC)
I don't think that high break down voltage implies high capacitance as this entry suggests. -RG Atlanta
This Page seriously needs an explanation of correctly connecting axial polarized capacitors. I have to look that up every time I work with Caps. I don't feel qualified to write it up or I would add it myself!! —Preceding unsigned comment added by 74.203.110.1 (talk) 17:00, 1 July 2010 (UTC)
I remember reading somewhere that electrolytic capacitors only acquire a polarity after they have been used. The testing after manufacturing supposedly gave the polarity for most capacitors. Is this true? There are "non-polar" capacitors with cases and capacitances that are similar to normal electrolytic capacitors for sale here: http://www.allelectronics.com/cgi-bin/category/140900/Non-Polar.html --Pyrochem 03:47, 21 September 2006 (UTC)
I'm pretty sure the polarity for the -)|- symbol is wrong. I think the flat side should be positive. 68.40.101.59 01:05, 14 January 2007 (UTC)
I think this page should include a note that, compared with other types of capacitors, electrolytic capacitors break down with age. There's sort of a statement to this effect, that a positive voltage must be maintained or the electrolytic will break down. But old electrolytics are the overwhelming cause of hum in old AV equipment, so a statement along these lines might be helpful to someone.
Rock it out. max
"..electrolytic capacitor was invented in 1921 by Julius Edgar Lilienfeld ..." can this be true? There are numerous earlyer patents from Charles Pollak:
--141.30.240.194 09:46, 12 February 2007 (UTC)
--Elcap (talk) 17:31, 27 December 2007 (UTC)
I just edited this out of the page (it was an extra copy at the end of the list of types), maybe someone can check and edit:
Tantalum: compact, low-voltage devices up to about 100 2000µF, these have a lower energy density and are more accurate than aluminum electrolytics. Compared to aluminum electrolytics, tantalum capacitors have very stable capacitance and little DC leakage, and very low impedance at low frequencies. However, unlike aluminum electrolytics, they are intolerant of voltage spikes and are destroyed (often exploding violently) if connected backwards or exposed to spikes above their voltage rating. Tantalum capacitors are also polarized because of their dissimilar electrodes. The cathode anode electrode is formed of sintered tantalum grains, with the dielectric electrochemically formed as a thin layer of oxide. The thin layer of oxide and high surface area of the porous sintered material gives this type a very high capacitance per unit volume. The anode cathode electrode is formed of a chemically deposited semi-conductive layer of manganese dioxide, which is then connected to an external wire lead. A development of this type replaces the manganese dioxide with a conductive plastic polymer (polypyrrole) that reduces internal resistance and eliminates a self-ignition failure[1
Yes, 2200uF tantalums and even larger ones exist (check digikey). But the general use of tantalums dont't go beyond several hundred uF.
81.215.13.145 07:52, 4 June 2007 (UTC)
"However, unlike batteries, capacitor voltage is directly proportional to the total energy remaining" - the voltage is proportional to the square root of the remaing energy, isn't it? —Preceding unsigned comment added by 213.79.33.10 (talk) 23:55, 8 September 2007 (UTC)
Energy = 0.5 x capacitance-in-Farads x voltage-squared -69.87.199.150 13:10, 14 September 2007 (UTC)
I think it's using a more general sense, indicating that raising one will raise the other. Might be directly proportional, but not linearly proportional, if I get the idea right. KronesR (talk) 23:41, 7 March 2012 (UTC)
"The correct polarity is indicated on the packaging by a stripe with minus signs and possibly arrowheads, denoting the adjacent terminal that should be more negative than the other."
This article is generally pretty well done, but this statement about polarity marking is greatly over-simplified, with no acknowledgement of a century of history and different capacitor packages. It is too bad the article does not have a picture of a typical unpainted metal can electrolytic capacitor from decades ago. I think polarity was usually marked with a dot of red paint. Did this mark positive? And current small drop caps are also polarity marked with a dot of color. But does this mark positive or negative?-69.87.199.150 13:10, 14 September 2007 (UTC)
--- I agree. See above about dire need for instructions on correct reading of polarity and why its important when using polar caps. —Preceding unsigned comment added by 74.203.110.1 (talk) 17:10, 1 July 2010 (UTC)
The article still does not show common schematic representations of polarised capacitors and how that relates to the markings on the capacitor itself. When assembling a PCB which side of this symbol is positive : --| ||-- etc. There are several schematic representations to explain.
does this interfere with the functoning of the capacitor or the capacitor should be replaced? —Preceding unsigned comment added by 66.16.40.22 (talk) 14:06, 14 October 2007 (UTC)
Electrochemical double-layer capacitors (EDLCs), also known as supercapacitors or ultracapacitors are NOT electrolytic capacitors. They have to be cancelled here. Please compare with the german article. --Elcap (talk) 08:54, 20 December 2007 (UTC)
"Essentially, a 10 microfarad AC capacitor behaves like two 20 microfarad DC capacitors in inverse series."
If one cap shorts during each half cycle, then to obtain a result of 10uF one would need to connect 2x 10uF back to back, not 20uF. —Preceding unsigned comment added by 86.4.152.167 (talk) 14:10, 6 October 2008 (UTC)
What exactly does that mean? Why dont you descrbe what you mean step by step. —Preceding unsigned comment added by 86.4.152.167 (talk) 14:16, 6 October 2008 (UTC)
OK then... when wrong polarity is applied, the insulating layer begins to conduct. Hence for each half cycle we have one working capacitor in series with a low impedance. Hence 2x 10uF 'lytics in series gives 10uF, not 5.
I can indeed sign my posts with tildas, but I don't think it would be very useful given that I'm not logged in. —Preceding unsigned comment added by 86.4.152.167 (talk) 16:12, 7 October 2008 (UTC)
IRL there are a vast number of capacitors in successful service at over 15 yrs old. 15 year life expectancy is not a real world figure. Caps can die with age, but in reality the great majority don't. Some are even still in service from the 1930s. —Preceding unsigned comment added by 86.4.152.167 (talk • contribs)
I think that would be missing the point. The point is that despite these oft quoted short ratings, a sizeable percentage of lytics from half a century ago and longer are still working fine. Otherwise readers are liable to imagine that after 15 or 20 years most lytics are dead - and this is far from the case.
I have heard and read that Electros will change their capacitance if used on a much lower voltage circuit them they were designed for. I.E; a 100 mF 400V unit will lose capacity on a 16 Volt circuit due to less electrolytic action. To restore such a cap, or, any old one that you have a doubt about; simply connect it to a current-limited (a few mA) voltage source of about 70% of its rated voltage overnight. It will work in a "pinch" or if it is a vintage or very expensive cap you don't wish to,or can't, simply replace (ARRL Handbook)Tintinteslacoil (talk) 13:43, 24 November 2008 (UTC)
The section discussing tantalum capacitors seems to contradict itself:
Is it really true that tantalums simultaneously "have a lower energy density ... than aluminum electrolytics" and yet have "higher capacitance per unit volume" ? Is that "higher capacitance per unit volume" than aluminum electrolytic, or is that compared to the other kinds of capacitors in cell phones?
Rather than vaguely saying one is "higher" than another thing, would it be OK to print a typical value for each one? --68.0.124.33 (talk) 22:02, 16 October 2008 (UTC)
this sounds like a cross between a battery and capacitor its sounds weird that a capacitor would use a electrolyte where would you distinguish the difference between a battery and capacitor because this is made the same way as a battery?urName (talk) 08:05, 8 February 2011 (UTC)
Two things about it, more wording/formatting issues.
"These capacitors are stable in use between -55°C to practically 125°C in theory." "practically" and "in theory" don't go too well in the same sentence. Does it mean "close to 125 in theory" or that it could actually go as high?
The whole topic about OS-CON should go right after the Tantalum one. Seems there is a break, some text, then it goes to OS-CON. That "extra" part seems to belong to the Tantalum section. Should it be joined? — Preceding unsigned comment added by KronesR (talk • contribs) 22:07, 4 January 2012 (UTC)
Most electrolytic capacitors are polarized and require one of the electrodes to be positive relative to the other; they may catastrophically fail if voltage is reversed. This is because a reverse-bias voltage above 1 to 1.5 V[4][5][6] will destroy the center layer of dielectric material via electrochemical reduction (see redox reactions). Following the loss of the dielectric material, the capacitor will short circuit, and with sufficient short circuit current, the electrolyte will rapidly heat up and either leak or cause the capacitor to burst, often in a spectacularly dramatic fashion.
The new rewritten version has many grammatical flaws and basically removed everything from before. It would be nice to incorporate the old version from earlier this month into the new version, as both have their merits. — Preceding unsigned comment added by Theburn7 (talk • contribs) 11:57, 28 December 2014 (UTC)
There was nothing particularly wrong with the earlier article, although it was a bit disconnected in places, due to the number of contributors. You've basically turned it into your version of history. I seems that just about every non-english speaking country in Europe, claims to have invented just about everything, and there's always somebody determined to set Wikipedia straight. FORTUNATELY, anybody who wants to read a more balanced and comprehensible article, and not somebody's badly-written Term Paper, can access the History of this item. — Preceding unsigned comment added by 125.7.82.82 (talk) 01:58, 18 January 2016 (UTC)
Hi Wikis, I have written a complete new article about electrolytic capacitors and replace the old one Dec. 14. Yesterday the user “Wtshymansky” delete the new article and restore the superior version. Everybody who wants to follow the discussion can have a look at the new article under User:Elcap/Electrolytic capacitor.
The reason I wrote a new article was the destroying of the article Capacitor plague in Feb. 2014. Trying to repair this article I saw, that the English Wiki had no article about Aluminum electrolytic capacitors. But to understand what happened with failing capacitors using a wrong electrolyte it was necessary to write an Al-e-cap article first. By the way I wrote an article about Niobium capacitors and add some paragraphs in the article Tantalum capacitors, all members of the great family of electrolytic capacitors. Remained the question of what happens with the old article “Electrolytic capacitors”?
This old article really is a conglomeration of superficial knowledge and wrong information. Let me give some examples:
The first sentence: - An electrolytic capacitor is a capacitor that uses an electrolyte (an ionic conducting liquid)…. This is incomplete, most Ta-e-caps use solid electrolytes. - ….uses an electrolyte (an ionic conducting liquid) as one of its plates to achieve a larger capacitance per unit volume…. is wrong, the thin dielectric layer coming from the anodic formation is the main reason for high CV. - They are widely used in power supplies…. is only valid for Al-e-caps, not for Ta-e-caps and Nb-e-caps - The rest of the introduction are preconceptions coming from outdated experiances.
In the part “History” the notice about Lilienfeld is wrong, sorry he was a genius but not for electrolytic capacitors. The remarks about “Mershon” are a very special information only for Americans.
The part “Types of electrolytic capacitors” is a collection of types, electrical parameters, antiquated values and wrong information. Starting with “Supercapacitor” not explaining that SCs are not e-caps down to OS-CON capacitors which are not available anymore with that mentioned solid electrolyte.
Going down the singe paragraphs I found a lot of antiquated, misplaced or wrong information in the old article so that I decide to write a new one to give precise information and to compare with tables and pictures the three different electrolytic capacitor types. This new article yesterday was replaced by the old one.
By the way, I have tried to overtake all valid refs from the old article into the new article, so that no information is lost.
I hope that this information about the new written article will start the discussion about the both article versions. (sorry for my English, I know it’s more Denglish, but I hope it is understandable in point of technical facts. --Elcap (talk) 15:47, 30 December 2014 (UTC)
The caption to an illustration claims that a 2 microfarad electrolytic capacitor was used in crystal radios. Quite apart from the fact there is nothing to decouple in a crystal radio, the only fixed capacitor likely to be found was that some designers put a capacitor of around 0.001 microfarads in parallel with the headphone (supposedly to shunt the residual R.F. from the crystal). In reality, removing it made no audible difference because the headphone was incapable of resolving radio frequencies. A 2 microfarad capacitor would have absolutely no use whatsoever. DieSwartzPunkt (talk) 16:45, 7 January 2015 (UTC)
Hi DieSchwartzPunkt, your question is correct, thanks for your attention.
Source 1: The Tantalum Supply Chain: A Detailed Analysis [1]
Page 29, Fig. 13 The shortage of material may only have been perceived, but there was a real increase in the price of tantalum materials. The spot price for tantalum ore is as reported by the London Metals Bulletin (Fig. 13)…..
In the last 30 years, there have been two short periods when the tantalum ore price was unstable. In the late 1970s, the price of ore jumped, then returned to nearly the same as that before the excursion. In 2000, the price rose quickly, then again returned to normal. Figure 14 graphs the performance of tantalum powders from 1965 to the present.
Please have a look at Fig. 13 and 14
Source 2:
Tantalum Availability: 2000 and Beyond W. A. Serjak, H. Seyeda and Ch. G. Cymorek, H. C. Starck, Inc./GmbH [2]
Page 14
In 1999 and 2000, the supply chain became more complex than usual. Media reports highlighted the tight supplies and increasing prices, precipitating a scramble for capacitors and tantalum across the chain. Double ordering started. Worst of all, speculators entered the supply chain, disrupting the normal flow of material by bidding prices that were higher than existing supply chain prices.
Conclusion: My text in the chapter history, sorry, has to be changed a little bit. Proposal:
The solid tantalum capacitors in this years offered smaller capacitors with lower ESR values than the aluminum capacitors, However, they were more expensive. Nevertheless they found more and more applications, also in entertainment devices. That ends abruptly in the late 1970s, as a price explosion for tantalum ore the application in radios and TV sets makes too much expensive. Small Al-single ended e-caps with low leakage currents will replace the tantalums. With the beginning of the SMD technology the tantalums came back as chips for flat devices. --Elcap (talk) 16:02, 8 January 2015 (UTC)
From the lede:
Due to their very thin dielectric oxide layer and enlarged anode surface electrolytic capacitors have—based on the volume—a much higher capacitance-voltage product compared to ceramic capacitors or film capacitors, but an <u>articulately</u> smaller CV value than electrochemical supercapacitors.
I can't decide what that is trying to say, but "articulately" is almost definitely the wrong word. 203.129.52.43 (talk) 08:48, 13 July 2015 (UTC)
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In the intro: "Applying a reverse polarity voltage, or a voltage exceeding the maximum rated working voltage of as little as 1 or 1.5 volts, can destroy the dielectric and thus the capacitor."
I think this conflates two separate conditions for failure. Probably should read: The dialectric can be destroyed by applying a reverse polarity voltage of as little as 1 or 1.5 volts, or a forward voltage exceeding the maximum rated working voltage, which thus also destroys the capacitor. Gwideman (talk) 08:56, 4 July 2020 (UTC)