Capacitors, Aqueous-Nonaqueous

[Brewster]

O.K. I'm aware of the debate between aqueous vs nonaqueous caps, but how do I determine if a cap is or isn't? More specificly Panny FJ,FK,FL and Ruby ZLH.
I haven't noticted it listed on data sheets, or am I just blind? Thanks.

[starfury1]

Re: Capacitors, Aqueous-Nonaqueous

No real answer for you

Actually that is an interesting question, I was wondering myself ?

I dont know, I guess maybe the manufacture publish something?
maybe the type of electrolyte used
(although I think they may keep that info close to their chest so as to speak)

PeteS in a post round here somewhere did talk about baking them @ temp
The ones that last the longest are would most likely non aqueous type.

I go by whats said by those in the know here.
but yeah its a good point
Were do you get this information?

maybe something it the spec gives it away as being one type or another.
(but guess those here would want more then that as conformation of which type)

Can anyone comment on this

Cheers

[linuxguru]

Re: Capacitors, Aqueous-Nonaqueous

FJ, ZLH - aqueous.
FK - non-aqueous.
FL - unsure.

No specific electrical measurements are conclusive, but the ultra-low ESR caps are invariably aqueous, while caps specified as long-life are often non-aqueous. It's pretty blurry out there, especially for some Rubycon offerings like the ZT - they're aqueous, but have most of the properties of non-aqueous caps.

[gonzo0815]

Re: Capacitors, Aqueous-Nonaqueous

I think the higher the endurance and the higher the temp the lower the h2o content in the electrolyte and vice versa.
ESR values are related too, but this is a field of constant improvements in both fields.

Other then that and PeteS first hand test results you can`t answer this question.
And i assume, that no mfr will openly share this knowledge with anyone not affiliated.

[starfury1]

Re: Capacitors, Aqueous-Nonaqueous

i assume, that no mfr will openly share this knowledge with anyone not affiliated.

yeah thats what I thought Gonzo thanks

Thanks Linuxguru too.

Following on from the above it makes a bit of sense when you think FC are worst specs (in some respects) then FM but FC are suppose to be Non-aqueous and FM is Aqueous.
So what you use is going to depend on what parameters of the cap you need to exploit, and as always its a few things and some trade offs always come into play



I guess

this is a field of constant improvements in both fields.

is what will make it a bit harder to workout which is which and possibly we may not need to worry to much about it as time goes on.
(not that I think people overly worry now but from a design point its probably a good idea to consider and from a repair side for max life its good to know which type I suppose)

not really of any help to the original question but bit on electrolyte here

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

http://www.faradnet.com/glossary/e_gloss.htm#eccap

http://electrochem.cwru.edu/ed/dict.htm#e12

caps here

http://electrochem.cwru.edu/ed/encyc...electr-cap.htm


I'll have to find that post PeteS made on cooking them, got me wondering what he said now

Cheers

[PeteS in CA]

Re: Capacitors, Aqueous-Nonaqueous

Broad-brushing a bit, you may be able to infer which are aqueous-electrolyte types from a couple of things in the datasheets. Ignoring Rubycon for a moment, if you look at Panasonic, UCC and Nichicon, the non-aqueous series, e.g. FC, LXZ, PW and PA, are rated for -55C and the impedance at -10C is double the 20C impedance. The aqueous series, e.g. FM, KY, KZE, KZG, HE, HD, HM, HN and HZ, are rated for -40C or -25C (HM, HN and HZ) and the -10C impedance is ~3X (2.7X - 3.9X is the parts whose specs I checked out) the impedance at 20C. IOW, the performance of aqueous electrolyte caps at low temps falls off faster than the performance of non-aqueous caps. With UCC, their non-aqueous series are LX(x), while their aqueous series are KY or KZ(x). With Nichicon, their non-aqueous series are P(x), while their aqueous series are H(x).

The above seems true of Rubycon low impedance parts, with the possible exception of the YXF series. YXF is rated for -40C and the -10C impedance is ~3X the 20C impedance, suggesting that the electrolyte is aqueous, but one of their marketing types told me that it is non-aqueous. My guess is that either he misunderstood my question or that he is incorrect. ZL is the low impedance, long life series Rubycon is recommending for demanding applications such as power supplies and DC-DC converters. VRMs may need the ultra low impedance of MCZ.

[linuxguru]

Re: Capacitors, Aqueous-Nonaqueous

PeteS: Thanks, that's a very useful criterion. Even if the datasheets don't show this information, a test rig consisting of an AC bridge, a thermometer, some dry ice/refrigerator, and a few other odds and ends is enough to measure the impedance/temperature curve sufficently accurately to make this determination.

[starfury1]

Re: Capacitors, Aqueous-Nonaqueous

Thanks PeteS....
So the Above "As a rough rule of thumb" but no Guarantee comes with it
(thats what I suspected something it the specs might give it away)

[PCBONEZ]

Re: Capacitors, Aqueous-Nonaqueous

Suggestion:
See if you can locate the MSDS (Material Safety Data Sheet) for what ever series you want to know about.