Post help identifying capacitors here - Page 3

**jiroy** · 01-11-2023, 03:04 AM

Quote:

Originally Posted by rattlesnake

Beautiful, thanks again

Welcome Friend ..

**momaka** · 01-12-2023, 11:44 AM

Quote:

Originally Posted by jiroy

You always take the first value for Capacitance and the second for voltage , that's the standards .

Depends. I've seen plenty of sleeve-less / SMD electrolytics capacitors labeled with the capacitance first and voltage second. Actually, most SMD polymers and electrolytics are labeled like that. Some won't even have a voltage on there, but rather a voltage code letter. So if there is any standard anymore, it surely doesn't seem to be followed very well.

Quote:

Originally Posted by rattlesnake

Thank you

Does the "s" in "16s" mean volts? otherwise how can you tell what is what? I mean could there be a 10v 16µF cap? how would you tell them apart?

The real teller here is the fact that 16 uF is not a standard capacitance value.

Generally, the standard values for capacitance are 100, 120, 150, 180, 220, 270, 330, 470, 560, 680, and 820... multiplied or divided by any coefficient number of 10.

So in the 10's range, you can have 10 uF, 12 uF (uncommon, but does exist), 15 uF, 18 uF (uncommon), 22 uF (very common!), 27 uF (uncommon), 33 uF, 47 uF (very common!) 56 uF, 68 uF, 82 uF... and a wrap again at 100 uF (10 uF x 10).

In contrast, voltage ratings follow a slightly different set of values.
For voltages below 10V, the common values are 2.5V, 4V, 6.3V, and 10V.
Between 10V and 100V, it's 16V, 25V, 35V, 50V, 63V, 80V, and 100V...
And for higher values, it's the same number multiplied by 10.... though there are a few additional values, like 200, 220, 315, 400, 420, and 450.

rattlesnake · 01-12-2023, 12:51 PM

Quote:

Originally Posted by momaka

The real teller here is the fact that 16 uF is not a standard capacitance value.

I thought so! But I wasn't familiar with all the values you described. Thank you for taking the time to enumerate them all. I'm sure I'll come back to this post some day.

mach128x · 01-16-2023, 04:02 PM

I need help identifying this manufacturer.
On the logo the letter "m" is pretty obvious, with what could be the letter "L" attached under it (or just some hockey-stick looking graphical swoosh).
I’ve search capacitor.web.fc2.com and spent hours in google image search, to no avail.
Thanks in advance.

It's a 220 uF 16V from the switch-mode power supply inside an M-audio studio monitor. I suspect a low-ESR...

**momaka** · 01-16-2023, 04:13 PM

Quote:

Originally Posted by mach128x

It's a 220 uF 16V from the switch-mode power supply inside an M-audio studio monitor. I suspect a low-ESR...

If it's in a SMPS, it probably is (or should be) low ESR.
But don't worry about identifying it or finding a datasheet for it. I stopped bothering to look up obscure manufacturers a long time ago. In all cases, I just use a low ESR capacitor from a known good Japanese brand (like Panasonic, Rubycon, Nichicon, and United Chemicon.) Never had issues replacing these obscure brands by such. In fact, these no-name garbage caps are so bad, that sometimes I've used very old Japanese general purpose capacitors for a repair or two, and even those have lasted longer than the cheapo caps.

mach128x · 01-16-2023, 05:10 PM

Quote:

Originally Posted by momaka

If it's in a SMPS, it probably is (or should be) low ESR.
But don't worry about identifying it or finding a datasheet for it. I stopped bothering to look up obscure manufacturers a long time ago. In all cases, I just use a low ESR capacitor from a known good Japanese brand (like Panasonic, Rubycon, Nichicon, and United Chemicon.) Never had issues replacing these obscure brands by such. In fact, these no-name garbage caps are so bad, that sometimes I've used very old Japanese general purpose capacitors for a repair or two, and even those have lasted longer than the cheapo caps.

I understand your point.
True, my hope was to find the original ESR rating, to find something in the same ballpark.
I was going to replace it with a good quality one in any case, for sure.

The question then, however. What's a good "low" ESR ? I've been told there can be such a thing as "too low" depending on the application. This particular cap sits on the output side, btw. (maybe this isn't the right section of the forum to discuss these details)

**momaka** · 01-16-2023, 05:32 PM

Quote:

Originally Posted by mach128x

The question then, however. What's a good "low" ESR ? I've been told there can be such a thing as "too low" depending on the application. This particular cap sits on the output side, btw. (maybe this isn't the right section of the forum to discuss these details)

Well, for the output of PSUs, generally you want to avoid the lowest ESR series... but even then it depends on the PSU, or rather its design.

Discontinuous / flyback designs (you can distinguish those fairly easily, as they don't have an output toroid after the rectifier(s)) don't care about too low of an ESR. They may get a little more noisy (as in, audible noise and not necessarily electrical noise) with very low ESR caps. But apart from that, they would work fine.

Continuous designs, on the other hand (these you can identify by a large output toroid inductor after the rectifier(s)) can be a little more picky. So with those, it's better to avoid the lowest ESR series, unless the PSU uses such already.

Which brings us full circle back to your question: how would we know what kind of "low ESR" caps the PSU used if we can't identify them?
- IME, I just haven't seen any of the no-name manufacturers to offer very low ESR caps. At best, they might have something that resembles United Chemicon KY or Nichicon HE or Rubycon YXG (which would be considered "mid-grade" low ESR more or less)... but almost never, really. More often than not, a cheap manufacturer's "low ESR" series will be barely a notch better than general purpose series from the Japanese manufacturers. The "better" ones might be comparable to entry-level low ESR series like Rubycon YXJ, Nichicon PS/PM/PW, UCC LXY/LXV, and Panasonic FC.

So this is why I don't bother to look up obscure brands anymore. I just pick some caps anywhere between entry-level low ESR and "mid-grade" low ESR, and know that I will be pretty safe with that choice. If I feel experimental (or if it's a discontinuous/flyback design), I sometimes go with very low / ultra-low caps that I might have on hand... and even with those, I haven't had any issues. At worst, I've had one or two flyback-based PSUs just "whine" a little more when lightly-loaded or in standby mode.