Identify this CAP Teapo pics included.

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Mr RB said:
Modern caps use much better electrolytes than the caps from 30-40 years ago. They don't need the higher voltages to get good plate charge formation and they almost never need "conditioning" any more. Both those concepts are pretty outdated.
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Yes, he's basing his opinions on long outdated technology - and considerably more than 30-40 years ago.

However, as for 'better electrolytes', there's been some really crappy modern electrolytes as well
 
30 - 40 years ago? Are you trying to age me? If capacitors have advanced so far that these issues are no longer relevant, it didn't happen 30 - 40 years ago. What I wrote may be a little dated to the point it isn't as critical, but still worth considering.
 
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BrownOut said:
30 - 40 years ago? Are you trying to age me?
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No, just pointing out how long ago (and I would say considerably more than that) any such potential problems may have existed. I would suggest pre-60's, if not pre-50's - it's a LONG time ago, and of no relevance since.
 
I wasn't building amplifers in the 50's or 60's. I was running around in diapers. The relevance is much, much more recent. Some manufactures still publish guidance as to minumum voltage.

I suppose my experience with amp production points out the difference between "world class" products and the jellybean products others make.
 
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BrownOut said:
I wasn't building amplifers in the 50's or 60's. I was running around in diapers. The relevance is much, much more recent.
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You said you were told this by an older guy, I'm presuming he was basing this on experiences way back then? - or just on his imagination?.

I've built and repaired stuff since the 60's, professionally since 1971, never had any such problems, and never heard of any such problems.

The ONLY thing I have heard of, is 'reforming' main electrolytics in antique radios when they haven't been used for years and years. I've never seen or heard of any problems personally though, but it's been a long time since I played with old valve radios - and they may have not been unused for long enough.

Some manufactures still publish guidance as to minumum voltage.
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Perhaps you could provide an example?, a previous poster has tried four different manufacturers and they don't - and no one else on these forums has heard of such a thing.
 
The "older guy" helped to found one of the most successful amplifier companies. He had decades of experience and was knowledgable of the most modern components. We took excruciating measures to build the very best products available. If the competition, or anyone else didn't, that was irrelevant. That's what made us "world class" and our customers understood the difference between us and the other guys. So anyway, this is where I cut my teeth in design, and I think what I learned is still relevant, though advances in component manufacturing might have lessened this as a critical issue. I'm willing to bet that designers at the company still carefully watch the minimum voltage on their electrolytics.

He checked a whole 4 manufactures. Wow! That must have taken all of 5 minutes!

Epcos has the following in their literature:

The DC voltage applied to the capacitor terminals must not exceed it's rated operating voltage, as this might increase the leakage current and may damage the capacitor. It is recommended to operate the capactor at 70 - 80% of it's rated voltage to optomize it's service life.
Also see ARRL recommendations posted above.

That you've never heard of any such thing leads me to believe my other experts on this issue. Looking at the data for the last couple days, it's apparent they were talking about "optomization" rather than just making something work. Still, it's an easy requirement for me to follow, so it only makes sense.
 
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I've also been and checked on the EPCOS site, never heard of them before.

Their technical document https://www.electro-tech-online.com/custompdfs/2009/10/PDF_GeneralTechnicalInformation.pdf appears to completely contradict what you've been saying:

 
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It didn't contridict what I've been saying. You just didn't read far enough.

Also,

 
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BrownOut said:
It didn't contridict what I've been saying. You just didn't read far enough.
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What's the relevence of the company details?, and why would I read that?.

As the quotes I posted were cut and pasted from their technical literature, it obviously completely contradicts what you've been saying - and I read to the end of it.
 
BrownOut said:
It obvoiusly does not contradict what I've been saying. I've said all along it's an optomazation.
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Yet the technical data I quoted says otherwise, and that running at lower voltage extends the life of the capacitor.

Newer literature from the company shows what I'm saying. https://www.epcos.com/inf/20/30/db/alu_x/B41161.pdf

The recommendations are a result of newer literature, not lead type.
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I would say it's entirely a question of lead type - SMD electrolytics are VERY different to normal leaded ones.
 
Whatever man,

The technical data I quoted was more up-to-date, and gave a tighter recommendation for operating voltage. "Lower" is non-specific. How much lower??? etc.

No, the difference is updated literature. Lead type doesn't matter.
 
recently i got 1F/5.5V panasonic and i was told my capacitor will be best performing if it is charged at it's rated voltage.

i disagreed with that and they told me "search it..."

search it where?
 
As far as I know the "minimum voltage" issue was from the days of the OLD electrolytics, those big ugly paper dielectric models (I'm sure Nigel remembers, as would the amplifier engineer of 30 years experience).

The paper (and some early plastic) dielectric was thick like cardboard and the caps were huge. Because of the thick dielectric they needed a high enough voltage to achieve a plate charge and start working like a capacitor, if the voltage was too low they were more like an open circuit (or a high ESR problem). So you had the need to "condition" them especially if they were high voltage ones like 400v ones in valve amps etc.

Modern electrolytics use incredibly thin dielectric films, that's why a 2200uF cap now is like your pinky finger and in the '70s it looked more like the size of an egg!

With the really thin dielectrics and good electrolyte they work great from even very low voltages. You could try measuring a 63v cap's capacitance at 1v and then at 63v, I really dont think you'd find much of a difference.
 
This I guess you should call up capacitor manufactures and educate them about their products. Some still think their caps work better within a voltage range.
 
BrownOut said:
This I guess you should call up capacitor manufactures and educate them about their products. Some still think their caps work better within a voltage range.
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They seem to know already, it's only YOU which seems to think otherwise, with the possible exception of certain makes of SMD capacitors?.
 
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