The Good Capacitors Photo Thread

[PCBONEZ]

Originally Posted by Behemot

What are old Phillips caps from begining of 90's like? I also found Roederstein caps, as I read here they are part of Vishay now, but are these old ones better than now or total craps too?

15-20 + year old caps and very likely dried out by now.

[Behemot]

Are these SMD's really Chemi-Con? There is like a their logo, but it's very small and the 8R/8N don't seem to be names of series.

I also founded some low Panasonic caps without serie label at all. Any idea which ones these could be?


Thanks.

[PCBONEZ]

Either Chemicon or Sam Young.
Sam Young sometimes makes caps for Chemicon.
They 'stole' Chemicon's logo for a while until Chemicon files a suit.
Then for a while Samyoung just added a dot in the middle of the shield before making their own logo.
http://www.samyoung.co.kr/sub_info/history_eng.asp
http://www.samyoung.co.kr/sub_produc...nfo_list_s.asp

The Panny without logos might be straight Matsushita instead of Panasonic.
Matsushita is the parent company.
They have made caps from time to time but they don't do retail [only sell direct to manufacturers] so they might feel they don't need a series mark as they are essentially made-to-order and bypass the normal distribution network.
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[Behemot]

Thanks for the info, I think I've encountered the Chemi-con logo with dot once, labeled United Chemi-con. I hope the Sam Young caps have some quality if they make caps for Chemi-non from time to time (hope they do not make the known problematic series ).

As for the Panny/Matsushita, these are from old CD-ROM drive, I'll be attentive to re-use them only out of PSU's :

[PCBONEZ]

The danger [one of them] of using old caps is that electrolytic caps reform in service.

Reform means the thickness of the aluminum oxide layer [which is the dielectric] changes.
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The thickness of that layer determines how much voltage the cap can handle without [what I will call] microscopic arcing between the plates. Once that arcing starts it gets worse quickly because the arcing burns off even more oxide layer leading to more arcing. The cap is 'done' at that point. It's on its way to becoming a short.

A used cap might say 16v on the label but if it has been in a 2v circuit then -now- it is only a 2v cap. [The oxide layer got thin in use.]

I hope that makes sense.

....

Old but unused electrolytic caps have a similar problem because the oxide layer in unused electrolytic caps gets thinner over time.

...

The oxide layer in lytics can be restored through a process called [what else?] reforming.

- There are as many different methods as people that do it...
Here is the Basic idea, look up more info on it if you plan to try it.
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Use a DC power supply with an adjustable voltage and a resister [to limit current] and apply a small voltage [1 or 2 vdc] to the cap[s].
[This can be done in batches of caps vs one cap at a time.]
Then every 10 minutes or so raise the voltage 1 volt until you get to the voltage marked on the caps.
Let it sit at rated voltage for 20-30 minutes.
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This will bebuild the thickness of the oxide layer without any internal arcing.
-
[At the factory when caps are first built [depending on what the caps design can handle] they go to 120% to 150% of the rated voltage but that is to increase shelf life and isn't needed for caps you will use in a year or so.]
.

[Behemot]

I've read something about reforming, but than elsewhere somebody wrote that high-quality caps keep their specs over long time of use and actually do not need to be reformed.

[Per Hansson]

Originally Posted by Behemot

I've read something about reforming, but than elsewhere somebody wrote that high-quality caps keep their specs over long time of use and actually do not need to be reformed.

I think this would be in relation to storage in that case (I.e. when the caps have never been used)

[PCBONEZ]

Originally Posted by Behemot

... high-quality caps keep their specs over long time ...

Right, just like they last longer in a circuit.

Originally Posted by Behemot

... actually do not need to be reformed.

Wrong. It's called Shelf Life. They all have one.

[Pyr0Beast]

Alluminum caps rarely short out in service. Usually they just dry out or bloat.
Never had one explode or bulge even if it was old, but that is 5years top.

However, tantalums are a completely different story. Those suckers will burn a hole in your board for no reason at all.

[lmcancu]

Why are Chemicon KZG caps still in this thread?

[ratdude747]

Originally Posted by lmcancu

Why are Chemicon KZG caps still in this thread?

Because at the time they still thought thought KZG was good. Once KZG had been out a few years we figured out that they had issues.

I've since edited in a disclaimer.

[DJduck]

Quick question here! I got some presumably Panasonic FR capacitors off some dead motherboard, but i am not sure if they are real. They have the usual T shaped vent and they look like Panasonics, but there is no [M] logo on them. They are rated for 16V 100uF and the printing quality is somewhat questionable (big print). 16V 1000uF 105c FR 23IDA.

[mariushm]

Panasonic FR series doesn't have the M logo on them, and it's plain white ink on black plastic.

I actually have some 100uF 16v panasonic FR capacitors, here's how they look:



btw, the 100uF shouldn't have a T vent at all, the size is too small for the capacitors to do any real damage or have enough gas to explode, so usually such small capacitors don't have any vent.

[DJduck]

I know small caps don't have vents I meant 1000uF not 100uF They are probably real ones. Thanks for a quick reply mariushm!

[Nevakonaza]

Really informative thread,Thanks OP!

[DJduck]

Here are some caps i have, that i do not think they have pictures of them posted here.

Panasonic FZ: Dark blue, light golden stripe.
IMG1094.jpg

Panasonic HFQ: Got them from a Compaq branded psu (probbably Delta). Dark blue, white stripe.
IMG1087.jpg

Philips M series? Not sure. Got them from an old monitor. They seem fine, i use them for psus. Blue, black stripe.
IMG1086.jpg

Panasonic FJ: Black, golden stripe. Very good caps.
IMG1090.jpg

Panasonic FR: Black, white stripe. NB! They do not have the [M] logo, but they are genuine! (thank you Mariushm for the info!)
IMG1084.jpg

Rubycon W: Very old caps, from an old monitor. I use them for psus, probably not low enough ESR for boards. Light blue, dark blue stripe.
IMG1091.jpg

Fujitsu M: Yellow, black stripe. Not sure of the quality, should be ok. Vent is like the Sanyo K vent, but different from Rubycon K vent.
IMG1092.jpg

Panasonic FL: They look like polys (4v, 680uf, tiny, flat top, no vent) Black, golden stripe.
IMG1089.jpg

Sanyo CZ: Light green, white stripe.
IMG1088.jpg

Nichicon RZ: Not sure if genuine, they have a generic round (circles) bung. Black, white stripe.
IMG1085.jpg

[JimboJet]

Can anyone give light onto good Ceramic caps? What brands should I go for and what rating for motherboards/gpus?

[Behemot]

As for SMD ceramics, the best is X7R electrolyte, I think it does not really depend from which manufacturer but maybe somebody will correct me.

As for radial ceramics, not really sure, I usually buy whatever they sell me in shop if I need something and don't have it "on stock" digged from already dead and dismounted HW.

[mariushm]

There are loads of types of ceramic capacitors... and there's several temperature ratings for such resistors, X5R, X7R and C0G/NPO being some of the best. NPO is actually above x5r and x7r as it's not as sensitive to vibrations (piezoelectric effect).

But these ratings are loosely defined... a x5r build with some specific components by a manufacturer could have the same performance as a capacitor rated as X7R by another company.. you can't be 100% sure.
Or, for example, a 2.2uF X5R in 0805 package may have the same performance as a 2.2uF X7R in 0402 or 0603 package (or footprint, whatever).

It's just safe to not go lower than X5R.

Read this article for some info about how ceramic capacitors are affected by voltage and temperature : http://www.maximintegrated.com/app-n...ex.mvp/id/5527

[masterpxhfhx1]

nice to know info!!!!!!!!!!!!