Where do you get your capacitors?!

[Per Hansson]

Re: Where do you get your capacitors?!

Here you go: https://github.com/madires/Transisto.../Documentation

[Demonata08]

Re: Where do you get your capacitors?!

Oh! Yeah, those little things are actually really awesome I have to save for their price, I'm not sure if you can adjust the frequency either. LOL I have a slightly different one knocking about. I think I might remember something in mind about being able to select capacitance testing from the menu instead of doing it on auto. I don't remember if you can adjust anything on it though either. LOL I do remember it being a little function generator. Let me Maybe poke around on a little bit..

There was no documentation with mine. And the user manual online isnt great.. Its written by someone with poor english skills and they dont go over much.

[Retro-Hipster]

Re: Where do you get your capacitors?!

Oh! Yeah, those little things are actually really awesome I have to save for their price, I'm not sure if you can adjust the frequency either. LOL I have a slightly different one knocking about. I think I might remember something in mind about being able to select capacitance testing from the menu instead of doing it on auto. I don't remember if you can adjust anything on it though either. LOL I do remember it being a little function generator. Let me Maybe poke around on a little bit..

[Demonata08]

Re: Where do you get your capacitors?!

Oh! Ok. Well, with it being a 470uf capacitor, try testing it at 120hz. About 95% Adidas sheets you will find for electrolytic capacitors will always say to test it at 120 hertz.

Also, that esr might actually be fine too.. Looking at some general purpose caps, I'm seeing a lot in the 300mOhm range, so that is probably fine really... Sorry, i didn't mean to give inaccurate information. :x I think I've just gotten used to having some pretty good caps around. LOL the ones I just tested were 0.01ohms at 470uf / 250v.. I measured these.
https://cdn.badcaps-static.com/pdfs/...b186d3a49a.pdf

Ill be honest in saying, i bought the esr meter before you mentioned the whole frequency thing. as a result i have this meter. Its actually a neat little device but i dont think it can test at different frequencies. im not even sure what its testing at.

[Retro-Hipster]

Re: Where do you get your capacitors?!

Oh! Ok. Well, with it being a 470uf capacitor, try testing it at 120hz. About 95% Adidas sheets you will find for electrolytic capacitors will always say to test it at 120 hertz.

Also, that esr might actually be fine too.. Looking at some general purpose caps, I'm seeing a lot in the 300mOhm range, so that is probably fine really... Sorry, i didn't mean to give inaccurate information. :x I think I've just gotten used to having some pretty good caps around. LOL the ones I just tested were 0.01ohms at 470uf / 250v.. I measured these.
https://cdn.badcaps-static.com/pdfs/...b186d3a49a.pdf

[Demonata08]

Re: Where do you get your capacitors?!

I would say that the ESR in that seems a bit High, but capacitance wise that isn't really bad. Capacitance in a line can vary 15 or 20% of its rated value. 450 microfarad is pretty good. The ESR should be lower, something like 0.15ish or lower, but that could again have something to do with the frequency at which the meter is testing. If it is testing at a higher frequency than it will artificially bloat ESR.

I wouldn't expect those capacitors to be the cause of the issue, but I fear I'm woefully under experienced to say that with any certainty. LOL I fixed quite a few things in my life but I honestly just haven't fixed monitors. I also and pretty s*** at fixing amplifiers. Haha I think there are definitely some others on here that would be able to give you a much better answer than I have. Still, I would assume that the use of an electrolytic in the application would mean low frequency switching and that the size of the capacitor would mean it would be for a part of a power supply section of some kind. I wouldn't expect that level of issue from such a small discrepancy in capacitance or ESR.

Does anybody else have a better answer for this one? LOL

I honestly cant find a data sheet on this capacitor to figure out what frequency to test it at.

[Retro-Hipster]

Re: Where do you get your capacitors?!

I would say that the ESR in that seems a bit High, but capacitance wise that isn't really bad. Capacitance in a line can vary 15 or 20% of its rated value. 450 microfarad is pretty good. The ESR should be lower, something like 0.15ish or lower, but that could again have something to do with the frequency at which the meter is testing. If it is testing at a higher frequency than it will artificially bloat ESR.

I wouldn't expect those capacitors to be the cause of the issue, but I fear I'm woefully under experienced to say that with any certainty. LOL I fixed quite a few things in my life but I honestly just haven't fixed monitors. I also and pretty s*** at fixing amplifiers. Haha I think there are definitely some others on here that would be able to give you a much better answer than I have. Still, I would assume that the use of an electrolytic in the application would mean low frequency switching and that the size of the capacitor would mean it would be for a part of a power supply section of some kind. I wouldn't expect that level of issue from such a small discrepancy in capacitance or ESR.

Does anybody else have a better answer for this one? LOL

[Demonata08]

Re: Where do you get your capacitors?!

Ah, Definitely recommend the DE-5000. Very capable and accurate on a really large range of capacitors and inductors. Also gives you just about all the info you could measure for capacitors as well. It's the one I use because I, like you, am just a hobbyist and don't want to spend 500+ on an esr meter. haha

Oh, and bonus nachos, it can be powered from a wall so you can leave it as a bench tool. Oh, one of the attachments it comes with uses some crappy crock clips though. They work, but I'd recommend looking at some youtube videos on switching them over to kelvin clips/leads. It cost about 20$ to do and is much more useful.

Gotcha. Thanks! got that one on the way now too. I got a pretty cheap one initially. Can i ask you, do you think two 250v 470uf capacitors reading 450uf 0.23 esr would cause power failure at the highest brightness? all the other caps on this rig are excellent. It runs perfect if i put it at substandard brightness. Thanks again

[Retro-Hipster]

Re: Where do you get your capacitors?!

Ah, Definitely recommend the DE-5000. Very capable and accurate on a really large range of capacitors and inductors. Also gives you just about all the info you could measure for capacitors as well. It's the one I use because I, like you, am just a hobbyist and don't want to spend 500+ on an esr meter. haha

Oh, and bonus nachos, it can be powered from a wall so you can leave it as a bench tool. Oh, one of the attachments it comes with uses some crappy crock clips though. They work, but I'd recommend looking at some youtube videos on switching them over to kelvin clips/leads. It cost about 20$ to do and is much more useful.

[Demonata08]

Re: Where do you get your capacitors?!

Yeah, it's one of those things that really throw you when you first start measuring ESR. lol I was really sad when I got my ESR meter the first time and figured out it wasn't the point and shoot style I was used to with a multimeter. :'D

But yes, because Capacitors are frequency dependent it makes testing them somewhat challenging, even out of the circuit. The best advice I could give would be the idea of getting datasheets for the range of capacitance you work on for the type of capacitor you work with and familiarize yourself with the testing parameters they use. Most charts you find will not include the esr based on ranges of frequencies.

Actually, I didn't think about it, but the datasheets for the Sample Kits would be really good resources for this info. I noticed in those Nichicon datasheets it had the ESR settings listed for their stuff in groups based on capacitance.

---

It's hard to find good articles describing charge/discharge constant and how that relates to multimeters, but a clearer way of understanding this concept is actually the ones involving oscilloscopes anyways. If you read this article, for instance, it should give you an idea of what your ESR and Multimeters are going to be doing to figure out the capacitance. Then think about the implications of a higher frequency when the charge constant becomes to slow to yield measurable results due to the high frequency or the high capacity of the capacitor.
https://www.testandmeasurementtips.c...n-capacitance/

When you are testing really high capacity capacitors and you have a high-frequency charge/discharge cycle, it basically means that the meter is only going to see a linear charge curve. This makes it hard to extrapolate the total capacity of a capacitor because you can't (with real accuracy at least) estimate when the capacitor will fully charge.

Here is a really good video from aew2 on how to measure ESR with an oscilloscope. Your ESR meter will be doing the same sort of math he does.
https://www.youtube.com/watch?v=115erzCCxgE

I hope this all helped. Happy exploring your new tool! ESR meters are pretty invaluable, even if they might seem a little unintuitive at first.

Just curious. What kinda ESR meter would you recommend. something cheapish but accurate? I dont do this stuff professionally. its just a side hobby.

[Retro-Hipster]

Re: Where do you get your capacitors?!

Yeah, it's one of those things that really throw you when you first start measuring ESR. lol I was really sad when I got my ESR meter the first time and figured out it wasn't the point and shoot style I was used to with a multimeter. :'D

But yes, because Capacitors are frequency dependent it makes testing them somewhat challenging, even out of the circuit. The best advice I could give would be the idea of getting datasheets for the range of capacitance you work on for the type of capacitor you work with and familiarize yourself with the testing parameters they use. Most charts you find will not include the esr based on ranges of frequencies.

Actually, I didn't think about it, but the datasheets for the Sample Kits would be really good resources for this info. I noticed in those Nichicon datasheets it had the ESR settings listed for their stuff in groups based on capacitance.

---

It's hard to find good articles describing charge/discharge constant and how that relates to multimeters, but a clearer way of understanding this concept is actually the ones involving oscilloscopes anyways. If you read this article, for instance, it should give you an idea of what your ESR and Multimeters are going to be doing to figure out the capacitance. Then think about the implications of a higher frequency when the charge constant becomes to slow to yield measurable results due to the high frequency or the high capacity of the capacitor.
https://www.testandmeasurementtips.c...n-capacitance/

When you are testing really high capacity capacitors and you have a high-frequency charge/discharge cycle, it basically means that the meter is only going to see a linear charge curve. This makes it hard to extrapolate the total capacity of a capacitor because you can't (with real accuracy at least) estimate when the capacitor will fully charge.

Here is a really good video from aew2 on how to measure ESR with an oscilloscope. Your ESR meter will be doing the same sort of math he does.
https://www.youtube.com/watch?v=115erzCCxgE

I hope this all helped. Happy exploring your new tool! ESR meters are pretty invaluable, even if they might seem a little unintuitive at first.

[Demonata08]

Re: Where do you get your capacitors?!

Ah, just the tip when you get your ESR meter in. ESR meters kind of expect you to know what testing conditions a specific type of capacitor will want generally. This is because capacity doesn't necessarily tell you what type of capacitor it is. For instance, most larger electrolytics should be tested at about 120 hertz which makes it a bit inconvenient in terms of testing their esr in circuit. ( you really should have at least 100k Hertz for testing in circuit) if you test one of these electrolytic with your ESR meter at a higher frequency, say 1khz-10khz, you'll get a very inaccurate esr or you won't get a reading back at all because it will simply be too fast a charge and discharge cycle to accurately get a charge or discharge constant measured. If you are unfamiliar with ESR meters, I always recommend that you grab the data sheets for the capacitors that you are testing or comprable capacitors and do your ESR tests based on the specs shown in the datasheet.

This dependence on how many hertz you should test a capacitor at is one of the things that make multimeters pretty bad at the job. It's not that they can't be good at it, it's that at the a very extremes (extreme High or low capacitance) the testing conditions they might be using might be incorrect for accurately measuring.

Just curious, is the same to be said if i test it off circuit? I want the most accurate reads i can get so i have no problem removing them. and also thanks for the info. i'm very much new to esr reading so i never knew that.

[stj]

Re: Where do you get your capacitors?!

if your stocking stuff keep in mind you can often get 16v caps the same size as the 10v ones - so no need for the 10v range.

the same goes for 35v instead of 25v.
watch the price difference on 35v stuff though.

[retiredcaps]

Re: Where do you get your capacitors?!

Whats the typical issue you deal with the most?

Usually obviously bad bloated caps on the secondary side.

[Retro-Hipster]

Re: Where do you get your capacitors?!

Ah, just the tip when you get your ESR meter in. ESR meters kind of expect you to know what testing conditions a specific type of capacitor will want generally. This is because capacity doesn't necessarily tell you what type of capacitor it is. For instance, most larger electrolytics should be tested at about 120 hertz which makes it a bit inconvenient in terms of testing their esr in circuit. ( you really should have at least 100k Hertz for testing in circuit) if you test one of these electrolytic with your ESR meter at a higher frequency, say 1khz-10khz, you'll get a very inaccurate esr or you won't get a reading back at all because it will simply be too fast a charge and discharge cycle to accurately get a charge or discharge constant measured. If you are unfamiliar with ESR meters, I always recommend that you grab the data sheets for the capacitors that you are testing or comprable capacitors and do your ESR tests based on the specs shown in the datasheet.

This dependence on how many hertz you should test a capacitor at is one of the things that make multimeters pretty bad at the job. It's not that they can't be good at it, it's that at the a very extremes (extreme High or low capacitance) the testing conditions they might be using might be incorrect for accurately measuring.

[Demonata08]

Re: Where do you get your capacitors?!

A multimeter may not be too accurate. Most electrolytic caps have a +/- 20% rating.

1200 * 0.8 = 960 uF.

Usually, the big caps don't go bad very often. I haven't replaced one yet. That will help keep the costs down vs buying an used power supply board off ebay.

Don't forget that the used power supply will have the same crappy caps to begin with. They may not look bloated, but may be out of spec.

Its funny to see that said. All ive replaced are the big ones. Although i havent done many so maybe im just unlucky. And yeah. I realize a failed cap with resistance can register as capacitance on these multimeters. I spent quite a lot on mine though. I dont think its been wrong yet. Normally the ones it shows as bad are bad. Still have that esr meter on the way though.

Whats the typical issue you deal with the most?

[retiredcaps]

Re: Where do you get your capacitors?!

A pretty multimeter that can also measure capacitance. it was days ago now but i think the two were measuring in the 800s. I have a nice ESR meter coming right now to double check them and a few other of my projects.

A multimeter may not be too accurate. Most electrolytic caps have a +/- 20% rating.

1200 * 0.8 = 960 uF.

Usually, the big caps don't go bad very often. I haven't replaced one yet. That will help keep the costs down vs buying an used power supply board off ebay.

Don't forget that the used power supply will have the same crappy caps to begin with. They may not look bloated, but may be out of spec.

[Demonata08]

Re: Where do you get your capacitors?!

How are you measuring the uF above? What test tool? and what is "way below capacity"?

A pretty multimeter that can also measure capacitance. it was days ago now but i think the two were measuring in the 800s. I have a nice ESR meter coming right now to double check them and a few other of my projects.

[retiredcaps]

Re: Where do you get your capacitors?!

like my current project at the moment, two 450v 1200 uf capacitors are way below capacity.

How are you measuring the uF above? What test tool? and what is "way below capacity"?

[Demonata08]

Re: Where do you get your capacitors?!

AH, yeah, that kind of sucks to find. haha I mean, there are definitely higher voltage capacitor kits from people like Nichicon (ie: https://www.mouser.com/ProductDetail...SABEgJPEfD_BwE ), but getting high capacity/high voltage type caps can be a bit rough in a kit. :/

This is the sort of thing I have just purchased 5(or 1 extra in the case of huge caps like that) of at a time every time I came to a part I needed but didn't have off of Mouser. I would be interested if there are any high capacitence+high voltage cap kits too but I suspect that they would be prohibitively expensive as it were.

Something I have done in the past is just buy some tv capacitor kits that had a wide range of capacitors, plus some of the big ones. The quality varies though.. nothing like what you get when you get sample kits from suppliers like Nichicon.

Thats actually a really good value kit. thanks for sharing! Now if i can get something like that between 100uf and even just 1000 but preferably 5000, I'd be set.