Since I Did Not Get an Answer I'll Ask Again + Some

[killian6pk]

My first question was with the very small caps like 0.1uf to say 2.2uf. Do these also need to be Low ESR for Monitor Power Boards etc?

Second Question: What are you looking for on a Data Sheet to identify Low ESR? Is it ripple current or impedance? And what type of datasheet info constitutes one or the other (range)? I have been checking my caps to try to identify the low esr that i might already have. Some say Standard or General Purpose, but them some don't say either of those two things. Just trying to get some education.

Third Question: Are Audio grade caps usually Low ESR caps or is that to broad to say that?

Fourth Question: The large filter caps. Do they need to be Low ESR or are you concerned with something else with them (100uf/450v.)? Also on Panasonic or Nichicon what series would you use?

See you should have answered my First Question.

Thanks For The Help. I have several monitors that I am trying to repair with the expertise of everyone here. I am learning a lot from reading the posts.

[Uranium-235]

Re: Since I Did Not Get an Answer I'll Ask Again + Some

1. Don't know

2. inpedence

3. sometimes, depending on what kind of audio device

4. power supplies aren't necessarily low ESR, infact there has been some recap attempts with lower ESR caps and they have caused stability issues. Going down in ESR is usually better for computer-based VRM's

[PCBONEZ]

Re: Since I Did Not Get an Answer I'll Ask Again + Some

1.
They need to meet or exceed the original specs.
If the originals are low ESR, then yes.
Originals that small are rarely low ESR in the app you specified [but could be] so you just have to check.
If not low ESR then choose the new caps by the Ripple rating.

2.
For most. - Impedance at 100kHz and 20°C - in Ohms.
[100kHz is close to the ripple frequency from an SMPS or a VRM.]
For caps intended for just after the first rectifier - Impedance at 100 or 120 Hz and 20°C - in Ohms.
[100 and 120 Hz are 2x line frequency depending on where you live. That's the frequency you get after the rectifier.]
-
Terms like "Standard", "Low ESR", "Ultra Low" have no official *standardized* meanings [no 'official' definition] so manufacturers can call their caps whatever they want.
Brand A's "Super Duper Ultra Extra Low ESR" cap series might be exactly equivalent to brand B's "Sort'a Low ESR" cap series.
- The terms are essentially meaningless.
- Ignore the terms and look at the specs.

3.
Sometimes.
"Audio Capacitor" also has no official *standardized* meaning so manufacturers can their caps whatever they want in regards to that. Some of the reasons they use to tag their caps with that name are pretty lame. [AKA: Complete BS.]

4.
Presumably you mean the caps that are huge relative to the other caps.
Those filter [smooth] the input rectifier.
They need to meet or exceed the original specs.
If the originals are low ESR, then yes.
Originals for just after the rectifier sometimes are and sometimes aren't low ESR.
If not low ESR then choose the new caps by the Ripple rating.
.
.
Designs vary A LOT. - There is no magic pill that -always- works.
If you want the proper caps you have to find out what the old ones are.
.

[killian6pk]

Re: Since I Did Not Get an Answer I'll Ask Again + Some

Thanks guys I'm still learning. You've been a big help.