Electrolytic caps and their 'CD' type (CD263, CD296, etc.) - what does it mean? - Page 1
Forum section: electronics / general

author: cvanc
author_rank: Frequent Contributor
timestamp: May 10, 2018, 06:11:55 pm
content: I recently noticed a 'CD296' marking on some electrolytics I was replacing. I have not seen this before and wonder if it's some kind of industry nomenclature?I did a little Googling and found electrolytics with other CD codes as well, like CD263. I found more than one manufacturer using these markings.Anyone know what (if anything) it actually means? Thanks.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 10, 2018, 06:25:52 pm
content: That's the family designation, but it only means anything to the manufacturer. I saw one link to rme.cn (a Chinese brand, it would seem) in a 12-year-old post. The domain looks to be dead now, likely the manufacturer is too.Any general purpose or low-ESR capacitor of the same or better ratings (capacitance +50/-25%, voltage >= rating, temp >= rating) will substitute.FWIW, that may be a "snap-in" type. The difference is sturdier (riveted?) leads. If it's that, match that too.Tim

author: GreggD
author_rank: Regular Contributor
timestamp: May 10, 2018, 06:44:00 pm
content: Cornell Dubilier ?? Was a big maker of caps.

author: dmills
author_rank: Super Contributor
timestamp: May 10, 2018, 11:47:41 pm
content: Still are for some things, they do some of the better SMT Mica parts for high power RF among other things, but that is clearly not a CDW part."For Audio" is generally to be read as "Not good enough for anything that matters" when seen on such things.Regards, Dan.

author: cvanc
author_rank: Frequent Contributor
timestamp: May 11, 2018, 12:01:50 am
content: Thanks all. Yeah, these were awful caps, leaked all over the place in a 4 year old unit, not overstressed,, not run hot, no reason to fail other than "they are junk".The brand is one I've never heard of - "RM" - and hope to not run across in the future.Swapped in suitably spec'ed Nichicons and all is well again.

author: amyk
author_rank: Super Contributor
timestamp: May 11, 2018, 02:09:48 am
content: https://www.eevblog.com/forum/projects/what-brand-of-capacitors-are-thesehow-critical-is-electrolytic-capacitor-brand/http://tech.dyg.com.cn/images/cp/dianrong/pdf/P00-4.pdfYou can find more info in the badcaps.net forums. The CD110 series seems to be "general purpose", CD263 is low ESR, CD296 is high temp/long life.

author: TimNJ
author_rank: Super Contributor
timestamp: May 11, 2018, 04:04:17 am
content: Here's my understanding.The CDxxx markings originate from the Chinese GB Standards, produced by the Standardization Administration of China (SAC). In those standards, they outline tons of different components and give detailed, standardized specifications for them. So, caps with a CD263 marking should adhere to the national Chinese standard for that part. I'm not exactly sure the motive behind that. (Maybe Blueskull would have an idea.)That said, I've seen parts marked CD288 from a bunch of manufacturers, and their specifications weren'tthatsimilar, so I'm not sure what to make of it. I'm guessing CD288, for example, is a low-impedance capacitor, and parts with that marking should have specifications which fall within a certain range.Interesting you bring this up as I was just reviewing a BOM at work and it called out a CD288 capacitor (with no manufacturer noted) and was curious what that was all about.https://en.wikipedia.org/wiki/Guobiao_standards

author: amyk
author_rank: Super Contributor
timestamp: May 13, 2018, 02:52:35 am
content: Quote from: TimNJ on May 11, 2018, 04:04:17 amOther countries have similar standards, e.g. JEDEC/Pro Electron/etc.https://en.wikipedia.org/wiki/Pro_Electronhttps://en.wikipedia.org/wiki/Soviet_integrated_circuit_designation

author: TimNJ
author_rank: Super Contributor
timestamp: May 13, 2018, 04:44:24 am
content: Quote from: amyk on May 13, 2018, 02:52:35 amYes of course. Just curious the motivation for creating the standard in the first place. I can see standardizing components like transistors and diodes because their characteristics are somewhat complicated. It's nice when BC547's from 5 different manufacturers arebasicallyall the same. But capacitors...why? Practically all you need to know is the ESR and the rated endurance (in hours) and you can determine if the cap is suitable.