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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 15th Apr 2017, 6:57 pm   #1
IanNVJ35
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Default What make of capacitors are these?

Sold by Maplin, 85 degree rated. Just wondering what the make was.

Thanks for any input.
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Old 15th Apr 2017, 10:02 pm   #2
Philips210
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Default Re: What make of capacitors are these?

Hi

It looks very much like the Samwha logo, minus the actual word 'Samwha'. I think the physically small electrolytics didn't have the room for the word in the logo.

Regards
Symon.

Last edited by Philips210; 15th Apr 2017 at 10:08 pm. Reason: typo
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Old 15th Apr 2017, 11:22 pm   #3
IanNVJ35
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Default Re: What make of capacitors are these?

Thanks - thought I had seen it somewhere. I was going to fit them but Samwha don't have the best reputation so I will hold out for Panasonic.
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Old 16th Apr 2017, 9:53 am   #4
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Default Re: What make of capacitors are these?

Shouldn't matter at that size. Even the really cruddy ones aren't much worse than the really expensive ones. 1000uF+ and things are different as ESR is relatively important.

However I always buy Vishay/BC these days because they're cheap and have thick leads so they can take a bit of abuse when prototyping. RS sell them in packs of 10 for smaller sizes for around £1 or so. This includes free next day parcel force as well.

Absolutely no reason to use Maplin these days IMHO.
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Old 16th Apr 2017, 11:39 am   #5
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Default Re: What make of capacitors are these?

The smaller the can, the worse some problems get. The water content tends to be proportional to the volume, whereas the leakage rate tends to be proportional to the surface area. Smaller parts lose volume faster than they lose seal area, and there is an impulsion to scale everything down, so the lendths of seals suffer as well.

I've recently replaced a load of 10uF 35v little tiddlers from a rather reputable brand of gear. A good 50% of them were in very poor condition ESR > 10 times spec.

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Old 17th Apr 2017, 6:18 pm   #6
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Default Re: What make of capacitors are these?

Also I have found to my detriment a couple of times that the small ones explode rather than vent if the electrolyte boils off. It's amazing the bang they produce!
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Old 22nd Apr 2017, 3:48 am   #7
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Default Re: What make of capacitors are these?

A few years back I found a site on the web from which one could identify the mfg. of an electrolytic like that from the"lines" on he top of the can.

I can't easily find the copy I made right now. But the lines in a "Y" config. meant one mfg, parallel lines meant another , lines in a "K" meant another, etc. Sadly, I can't remember the site, but it was a U.S. one.

Also always check the replacement for capacity and ESR before installing it.

Some knockoffs/ counterfits have the wrong values in the cans, and are often used, salvaged caps inside. I saw one with my own eyes labeled 1000 mfd at 50V and when the can was opened it contained a used 470 at 35 V. Not only that but to add insult to injury, it was a radial stuffed into an axial can with extension wires soldered on!
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Old 22nd Apr 2017, 4:42 pm   #8
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Default Re: What make of capacitors are these?

I have to say I've found Samwha to be ok. It's all about choosing the right cap for the job. For a critical switchmode I'd stick to Nippon Chemicon, Nichicon, Rubycon or the better Panasonics (since they do budget ones too).
One of my customers (a well known car plant) has 24V, 50A SMPSU's in machine tools and they use Samwha bus capacitors that can fail, though they're 15 years old or so.
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