NCC KMG or Nichicon VZ?

[Behemot]

Don't know which GP caps to take next time. I have had one instance of failed KMG (not replaced by me, it was there from the factory), on the other hand, KMG's are wastly more common out there. Also KMG's are cheaper. Otherwise they are the same spec to spec. Whaddaya suggest?

[theOracle]

Re: NCC KMG or Nichicon VZ?

as far as current production, I know of no capacitors that are currently "bad" or having issues from the 4 big names - Rubycon, Chemi-con, Panasonic and Nichicon - so any series currently sold via their authorized distributors should be fine. - Just match the specifications such as impedance, ESR, ripple current rejection, etc. of the original cap in the circuit

Digi-Key has a great filter tool that comes up in their main capacitor section and you can specify all kinds of characteristics such as temperature, impedance, size, etc. and it will show you which series match your originals!

[Behemot]

Re: NCC KMG or Nichicon VZ?

So, you work for Digi Key?

I am not asking if any of them is bad, I know KMG does it's 1000 hours as 105 °C. The question is, which of them can do much more?

[theOracle]

Re: NCC KMG or Nichicon VZ?

no, I do not work for Digi-Key, but I love their tool to select caps!

they are also the only large online distributor of capacitors in USA that has all four of the best brands (Rubycon, Panasonic, Chemi-con, Nichicon)

one of the characteristics than you can select using the tool that I linked to is the Lifetime @ Temp., so for example, you could limit your capacitor search to only those caps that have a life of at least 3000 hours @ 105 °C or 7000 hours or whatever you want!

[Behemot]

Re: NCC KMG or Nichicon VZ?

You talk to me like I never shopped there before but you are not answering any of my questions. Next, please!

[Pentium4]

Re: NCC KMG or Nichicon VZ?

Do you have a specific project you are going to use them in? I myself have never seen any failed KMG or VZ. Since KMG is cheaper I would pick those. I don't think you'd notice any huge difference between the two

[Behemot]

Re: NCC KMG or Nichicon VZ?

Replacing crap GP caps. I know usually GP caps are usually the least stressed but you never know…when replacing once than preferably forever

Found a bad KME, not KMG, bad memory, in this brick. But KMG is more or less the same as KME if I am not mistaken.

[mariushm]

Re: NCC KMG or Nichicon VZ?

They're both STANDARD type capacitors, they're not supposed to have any "special" characteristic, to make themselves noticed by anything.
And you're not supposed to care about it... pick whatever's cheaper or more readily available near you.

If i were to pick, I'd go with KMG simply for the higher temperature and because they're stocked at Farnell... well, usually... now i see Farnell has no Panasonic or Nichicon or Panasonic or UCC... guess it must be a database error or something.

[theOracle]

Re: NCC KMG or Nichicon VZ?

he is right about one thing, I just used the Digi-Key capacitor selection tool and looked at all of the KMG series, and they are almost all 1000 hours @ 105°C which is a pretty crappy lifetime, and the Nichicon VZ are also the same low 1000 hour durability.

I think if the equipment is worth the trouble of replacing the caps, you should use some with at least 3000 hours @ 105°C or higher!

[Behemot]

Re: NCC KMG or Nichicon VZ?

Both are 105 °C. The question is more like if any of them is known to last longer or if they are just so similar nobody noticed any difference.

[cheapie]

Re: NCC KMG or Nichicon VZ?

he is right about one thing, I just used the Digi-Key capacitor selection tool and looked at all of the KMG series, and they are almost all 1000 hours @ 105°C which is a pretty crappy lifetime, and the Nichicon VZ are also the same low 1000 hour durability.

I think if the equipment is worth the trouble of replacing the caps, you should use some with at least 3000 hours @ 105°C or higher!

I highly doubt you'll be running them at full ripple current at 105°C. Assuming 50°, that's about 32,000 hours, and that's still at full ripple.

[goodpsusearch]

Re: NCC KMG or Nichicon VZ?

Why not use entry level low esr caps?

[Behemot]

Re: NCC KMG or Nichicon VZ?

Many applications only work with certain cap types. I have learned it is safest to replace with same type as was the original so I stock both GP and low-ESR.

[goodpsusearch]

Re: NCC KMG or Nichicon VZ?

I have replaced GP caps with Rubycon YXF, a very entry level low esr and long life series without a problem.

[Behemot]

Re: NCC KMG or Nichicon VZ?

Just to be sure, I hope you understand you not running into problems yet does not imply such situations do not exist.

But such series may be interesting for situations where big GP cap is used and it goes wrong after some time, rather than small caps on feedback circuitry; many expensive pieces of equipment end on such problems on regular basis, I got first-hand experience for example with Siemens furnace using some NCC SMQ or similar caps. In such occasions I do not know if too-low esr cap would not break it but cap somewhere between should be OK and provide better life time.

[Behemot]

Re: NCC KMG or Nichicon VZ?

Just one typical application so you can imagine where I want to put such caps: some el-cheapo APC UPS, it has (among others) 6 Jianghai JH CD 11C (CX) 85°C caps, 22 uF/16 V. Datasheet is somewhat benevolent and says "max ESR" 9,4 ohm. Measure from 3 to 17,5 ohm

Will replace them with NCC SMG caps from some ancient CRT display (or whoever knows what from ) 22 uF/25 V (should not even exist according to datasheet). They measure 2,5-2,7 ohm (it starts at 3 but lowers after a while - they haven't been in use for something between 5 and 10 years so they are probably just reforming on-the-go), 25 uF.

Comparable Rubycon YXF states 0,9 ohm at 20 °C so you can see it's somewhat too low…yeah, there are probably applications for them so I may add them to my stock in future, but using combination of GP caps and typical low-ESR line like Nichicon PW is safe option.

[lexwalker]

Re: NCC KMG or Nichicon VZ?

Many applications only work with certain cap types. I have learned it is safest to replace with same type as was the original so I stock both GP and low-ESR.

You can use low ESR capacitors to replace general purpose ones. Done so many times already, as my own stock/spares are primarily low ESR ones. For power supply rails, either types of capacitors are useable. Even used them in some audio coupling and bias supply areas.

I have replaced GP caps with Rubycon YXF, a very entry level low esr and long life series without a problem.

Same here, but mostly Nichicons and Panasonics.

[theOracle]

Re: NCC KMG or Nichicon VZ?

You can use low ESR capacitors to replace general purpose ones. Done so many times already, as my own stock/spares are primarily low ESR ones. For power supply rails, either types of capacitors are useable. Even used them in some audio coupling and bias supply areas

you can definitely get into trouble using low-ESR caps in places that call for standard caps, too low of ESR in the caps for a circuit can cause oscillation problems - been there, done that, got the t-shirt

Same here, but mostly Nichicons and Panasonics.

both great capacitors, but no greater than Rubycon or Chemi-con

[lexwalker]

Re: NCC KMG or Nichicon VZ?

you can definitely get into trouble using low-ESR caps in places that call for standard caps, too low of ESR in the caps for a circuit can cause oscillation problems - been there, done that, got the t-shirt

Oscillation problems are mostly for switched mode power supplies (although I had not encountered any problems so far, perhaps I was not using ultra low ESR capacitors). Most of the time general purpose capacitors are found in standard linear power supplies, thus usually pretty safe to replace them with low ESR capacitors there (though have to watch out for LDO voltage regulators, always check the datasheet first). Had upgraded some audio equipment (where lots of general purpose capacitors were used) with those low ESR ones, and the immediate impact was the noise floor (hum, buzz and hiss) simply went down so much that can hardly hear them (almost inaudible).

[PeteS in CA]

Re: NCC KMG or Nichicon VZ?

Lex, any circuit with a feedback loop can oscillate: SMPSs; linear regulators; servo amplifiers; audio amplifiers; etc..