How to read these CAPS?

[tester272001]

Please have a look at my pic. These are SMD devices and maybe you can confim how to READ the values and rating? For instance is C556 a 470uf? And does the E mean the tolerance? or perhaps voltage rating? This circuit runs at 14V (approx). What doe E3 and UD mean ? Thanks for any insight someone can offer.

[mariushm]

Re: How to read these CAPS?

The one you point at is chip type electrolytic capacitor.

With polymer capacitors, the most common feature is that they don't have those grooves/cuts at the top because there's no electrolyte to cause pressure buildup inside. These ones do have the cuts so it's either electrolytic or functional polymer (a hybrid between el and poly).

With surface mounted capacitors of this type (square) and polymer capacitors, the general notation is that the largest size number is the capacitance... so in your case for C556, it is 470uF.

On very small capacitors where space is a premium, the last character in the number is the multiplier by 10 ... 471 = 47 x 10^1 = 470.

Most brands store above this value the series code or a date code, and below it there's a voltage code or the actual voltage rating. BUT it could be the other way around.
This brand stores a voltage code or the actual voltage (usually lowercase v, uppercase V can mean a code). You can see to the right C124 I think that's 4.7uF / 100V - that doesn't mean the chip is rated for 100v.

So how to determine voltage.... well, that's a tough one if you're not fixing stuff regularly.

I happen to know that the bent circle is the logo of Nichicon... this page is a good resource for identifying brands : http://capacitor.web.fc2.com/solidcapacitor.html (this link is only for solid capacitors , go at the top and click on "click here" to see the menu and whole site)

So knowing it's Nichicon, I can go browse their products list or datasheet and try to determine which series has the E3 code or UD code.

Nichicon's page is here: http://www.nichicon.co.jp/english/index.html

Going to chip type capacitors here : http://www.nichicon.co.jp/english/pr...hip/pict_f.htm ... I can see about the middle of the page an UD series, so the UD is probably the series code, therefore the E3 could be the voltage rating or something else.

Click on UD and you get a PDF with the datasheet... look on the first page on the bottom left.



(click once to zoom it)

Your capacitor is 8 or larger, so the second layout applies... you can see the digit below 470 is the voltage rating.

So since your capacitor has an E at the end, that means you capacitor is rated for maximum 25v.

And now you can go further in the datasheet and get the specs for your 470uF / 25v capacitor:

10 by 10 mm , 0.09 ohm impedance, 670 mAh ripple.

Now you can on Digikey and find replacement.... pick anything that has very close to or higher than that ripple value and very close or lower impedance, and has that surface size...

I found these for example:

http://www.digikey.com/product-detai...4-1-ND/2300371
http://www.digikey.com/product-detai...0CT-ND/1246020
http://www.digikey.com/product-detai...6-1-ND/3438900

etc ... basically select radial smd, 470uf, 25v, cut tape or bulk, sort by ripple then pick what have more ripple and less impedance compared to yours, and matches the 10 by 10 or whatever dimensions your capacitor has.

Notice the ones I linked to are marked as 10.3 by 10.3 - if you check the datasheets you'll notice they're actually 10 by 10. Either way the 0.3mm is too small to make a difference, you can solder them on your board.

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Fineprint: Cuts/grooves at the top are made as a relief for the case when the electrolyte in electrolytic capacitors goes bad and turns to gas building pressure inside the capacitor. There are electrolytic capacitors that don't have those cuts simply because they're too small or the capacity is small enough to not cause problems if they pop.

Also there are polymer "hybrid" capacitors (often called "functional polymer") that are a mix between electrolytic and polymer capacitors which have those cuts but you treat them as hybrid capacitors.


.... Too much Cola, too bored... long messages result.

PS. Please fill your country and relevant information in your profile... helps suggest where to buy stuff. As you said "landfill" in one of your posts I assumed it's US.