"Lasse Langwadt Christensen" <langwadt@fonz.dk> wrote in message news:055facb6-6101-4ff6-b482-501935dd6ebe@googlegroups.com...> >http://www.freepatentsonline.com/6939774.html >Close, though that seems to be tantalum. So those would be wet slug, hermetically sealed tantalum? Big big $$, not the same sort of thing we're talking about unfortunately. Neat to know what's inside them. I wonder if the same system works for aluminum. They don't claim aluminum on the patent, so it's probably somewhere between useless and corrosive? Who knows... Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/
Do Electrolytic Capacitors FREEZE?
Started by ●January 5, 2019
Reply by ●January 6, 20192019-01-06
Reply by ●January 6, 20192019-01-06
On Sat, 05 Jan 2019 18:48:46 -0600, tubeguy@myshop.com wrote:>I have never known what the electrolyte is made from, inside of >electrolytic capacitors. Is it a water based material, or oil based? >If its water based, it will likely freeze if left outdoors in cold >weather. For example, your car radio has caps, and if it's parked >outdoors in the winter, the caps in it will freeze. Yet, I have never >found my car radio working poorly in cold weather. This makes me believe >the electrolyte must be oil based..... > >Does anyone know?Yes, they are water based and freeze. ESR skyrockets below 0C. Some data sheets have graphs. Polymer lytics and dry tantalums are much better. In a power supply, the increased ESR will heat them up fast! -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●January 6, 20192019-01-06
<bill.sloman@ieee.org> wrote in message news:45749418-cb24-45c7-a533-59b30c479db7@googlegroups.com...> > Ions still migrate through solids - there are solid electrolytes - so ESR > won't become infinite, and might not even become all that large. >Yes, some. Glass is a good insulator at room temperature, but a modest conductor at nearly red heat (coincidentally at about annealing temperature). A matter of degree.> > With pure ice - and you won't get that inside an electrolytic capacitor - > ionic conduction is by quantum mechanical tunneling of hydrogen ions. >Sounds slow. If there are glycols as Lasse's example has, there could be a lot more opportunity for that. Those sorts of things tend to congeal rather than crystallize, AFAIK.>> and you're left with a much lower value capacitor (since, >> it is still a bunch of metal wound up together, and the dielectric >> constant >> of the frozen electrolyte will be modest; > > What makes you think that?Physics?>> but that'll be on the order of >> 0.1uF versus a nominal value of 1000s uF, useless for the same purpose). > > This sounds like your "infinite" ESR ... >Well yeah, I just described a parallel capacitor equivalent, where the electrolytic part (1000s uF) has a temp-dependent ESR, and in parallel with that is a small non-electrolytic part (~0.1uF?) probably itself with low ESR. And then ESL in series with all of that. And also an infinite series of loss factors associated with everything, if you must be precise... Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/
Reply by ●January 6, 20192019-01-06
On Sat, 05 Jan 2019 18:48:46 -0600, tubeguy@myshop.com wrote:>I have never known what the electrolyte is made from, inside of >electrolytic capacitors. Is it a water based material, or oil based? >If its water based, it will likely freeze if left outdoors in cold >weather. For example, your car radio has caps, and if it's parked >outdoors in the winter, the caps in it will freeze. Yet, I have never >found my car radio working poorly in cold weather. This makes me believe >the electrolyte must be oil based..... > >Does anyone know?https://www.dropbox.com/s/rxca65oxp3mj4at/e-fw.pdf?dl=0 Some numbers on the first page. ESR has a general negative TC but gets serious below 0C. https://www.avnet.com/wps/portal/abacus/resources/engineers-insight/article/understanding-esr-in-electrolytic-capacitors/ -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●January 6, 20192019-01-06
On Sat, 05 Jan 2019 18:48:46 -0600, tubeguy@myshop.com wrote:>I have never known what the electrolyte is made from, inside of >electrolytic capacitors. Is it a water based material, or oil based? >If its water based, it will likely freeze if left outdoors in cold >weather. For example, your car radio has caps, and if it's parked >outdoors in the winter, the caps in it will freeze. Yet, I have never >found my car radio working poorly in cold weather. This makes me believe >the electrolyte must be oil based..... > >Does anyone know?I like this question. We have -50C freezer at work that we have test to see if products start up down around -40C/F and they did after a couple of fixes... BUT they (PV charge controller) weren't ran at any power. What I would like to try is to place an electrolytic or two or three in there and bring out wires to be able to test this at say, -50C. And in-between temperatures if the caps are bad at -50
Reply by ●January 6, 20192019-01-06
On Jan 5, 2019, tubeguy@myshop.com wrote (in article<a3k23et3erkf726lcc6dpd53fgk4hcd6s2@4ax.com>):> I have never known what the electrolyte is made from, inside of > electrolytic capacitors. Is it a water based material, or oil based? > If its water based, it will likely freeze if left outdoors in cold > weather. For example, your car radio has caps, and if it's parked > outdoors in the winter, the caps in it will freeze. Yet, I have never > found my car radio working poorly in cold weather. This makes me believe > the electrolyte must be oil based..... > > Does anyone know?Yes, they can freeze. The aluminum electrolytics I was looking any a few years ago froze at -20 C or so, the main symptom being that the capacitance went down to one third of warm value, and the ESR rose. The big worry was that the regulators in the power supply tree could become unstable and oscillate quite heartily. Joe Gwinn
Reply by ●January 6, 20192019-01-06
krw@notreal.com wrote:> On Sat, 05 Jan 2019 18:48:46 -0600, tubeguy@myshop.com wrote: > >> I have never known what the electrolyte is made from, inside of >> electrolytic capacitors. Is it a water based material, or oil based? >> If its water based, it will likely freeze if left outdoors in cold >> weather. For example, your car radio has caps, and if it's parked >> outdoors in the winter, the caps in it will freeze. Yet, I have never >> found my car radio working poorly in cold weather. This makes me >> believe the electrolyte must be oil based..... >> >> Does anyone know? > > Capacitors are rarely a problem in automotive applications. Automotive > applications are generally specified from -40C to +85C, ambient. > There are many capacitors to choose from that will satisfy that range. > Inductors tend to be more problematic (and easier to forget to derate > - and tend to make things explode). Note that the electronics heats > fairly rapidly after the car is started so the lower end of the > temperature range is rarely a problem, particularly for infotainment > components.Why do inductors have an operating temperature range at all?
Reply by ●January 6, 20192019-01-06
"Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> wrote in message news:q0ttt0$6kh$1@dont-email.me...> > Why do inductors have an operating temperature range at all? >Ferrites freeze out a bit (not enough to ruin the spec in most cases, I think?), and obviously the upper limit is set by materials. I don't think there's anything beyond that -- just that they're not tested below there (and probably they can charge more if you want to buy ones that are?). Oh, and probably resins glassifying, and shrinkage. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/
Reply by ●January 6, 20192019-01-06
Joseph Gwinn <joegwinn@comcast.net> wrote in news:0001HW.21E2ABF3042A59A270000291B2CF@news.giganews.com:> On Jan 5, 2019, tubeguy@myshop.com wrote > (in article<a3k23et3erkf726lcc6dpd53fgk4hcd6s2@4ax.com>): > >> I have never known what the electrolyte is made from, inside of >> electrolytic capacitors. Is it a water based material, or oil >> based? If its water based, it will likely freeze if left outdoors >> in cold weather. For example, your car radio has caps, and if >> it's parked outdoors in the winter, the caps in it will freeze. >> Yet, I have never found my car radio working poorly in cold >> weather. This makes me believe the electrolyte must be oil >> based..... >> >> Does anyone know? > > Yes, they can freeze. The aluminum electrolytics I was looking any > a few years ago froze at -20 C or so, the main symptom being that > the capacitance went down to one third of warm value, and the ESR > rose. The big worry was that the regulators in the power supply > tree could become unstable and oscillate quite heartily. > > Joe Gwinn > >Essentially what happens is that your circuit is no longer your circuit because caps of other than designed values are currently what is in place at whatever temp below freezing you are at. So oscillations and various other non-optimal operational modes and failure modes can occur.
Reply by ●January 6, 20192019-01-06
"Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> wrote in news:q0ttt0$6kh$1@dont-email.me:> Why do inductors have an operating temperature range at all? >In the cold end they vary very little. In high temps a few things can happen. One is that the transformer varnish it was likely vacuum encapsulated in will liquify at some point. For HV applications, this can pose an arcing potential issue. Not likely but an operating range has to be stated, and it will likely be well below the melt point of any polymers or varnishes used in its make-up. This refers to miniature form factors of course. Huge oil bath power transformers are made with paper products and few polymers. There are plenty of isolation transformers, etc. and other designs where high temps pose no problem far higher than those a circuit board sized miniature can withstand.
