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Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 11:26 am
by chrismb
Hi Guys,

I was just idling for some mains smoothing caps (an ebayer [a regular seller I use]) who had some surplus 4900uF caps, but I let them go to a higher bidder as I didn't really need them (! y'know how it is... one 'accumulates' for that moment of need! ;) )

Anyhows, these items popped up in a search, and from the size of it I reckon this ain't what's marked on the can...

Any thoughts/opinions?:

http://www.ebay.co.uk/itm/230585886635

I'd expect a 1500uF/250V to have a bit more volume than this, but maybe I'm behind the curve on what can be done these days with electrolytic tech...

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 1:16 pm
by johnf
Chris
Nippon Chemicon is one of the most respected Japanese capacitor makers.
Aspect ratio of cap tends to suggest bulk storage and not high frequency ripple rated

however you can look up full specs on the web

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 2:19 pm
by chrismb
johnf wrote:Chris
Nippon Chemicon is one of the most respected Japanese capacitor makers.


An ideal brand to fake, then!?! :?

OK, thanks, I'll check the specs, and if it matches up I might buy a few. It's just for mains power, 50Hz.

I was just expecting an electrolytic of that kind of spec to be twice the volume of this one. Seems very compact for that spec.

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 2:30 pm
by chrismb
OK, that's pretty mad. I expect better preparation from the Japanese;

there are two products marked with the same KMH serial reference;

the snap-in product, as in the ebay listing; http://www.chemi-con.co.jp/e/catalog/pd ... 110701.pdf

and a screw in type; http://www.chemi-con.co.jp/e/catalog/pd ... 110701.pdf

Here's the rub; the snap-in KMH is only listed as available to 100V, suggesting the cap on ebay is non-kosha. But the photo on that spec sheet shows a 250V cap!!!!

:?

:?

I guess maybe its old stock on the ebay listing, and they've stopped the caps in that voltage rating?

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 3:42 pm
by Joe Jarski
Chris,
Try this link: http://www.mouser.com/catalog/specsheets/kmh_web.pdf

BTW, your datasheet that only goes up to 100V shows a picture of a 250V snap in.

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 3:56 pm
by chrismb
Joe Jarski wrote:Chris,
Try this link: http://www.mouser.com/catalog/specsheets/kmh_web.pdf

BTW, your datasheet that only goes up to 100V shows a picture of a 250V snap in.


Yup. I thought it odd too, that's why I commented on it being pictured there.

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 3:59 pm
by Joe Jarski
:lol: Oh yeah, you did... I must have spaced out about that point in your post. :oops:

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 4:02 pm
by chrismb
No worries. Thanks for the data sheet. I think I'll try a few of those, see how they work out. Seem to be a very cost-effective $/(V,uF).

Re: Chinese capacitors - cr@p, or good tech?

PostPosted: Sun Feb 05, 2012 4:06 pm
by chrismb
Incidentally, on the topic of high capacity capacitors; I've never really understood the advantage of the huge costs of, say, 10,000uF caps over the seemingly much lower costs of equivalents, say, 10 x 1,000uF. Excepting packaging/production constraints, are there any advantages of a single huge cap over multiple parallels? I can only see disadvantages.