Good or bad capacitor. How to determine this using ESR tables.

Thread Starter

bob2

Joined Jun 15, 2019
180
Hi all.
There are many different ESR tables of electrolytic capacitors; they all have different interpretations of the maximum allowable ESR.
It is clear that there is a dependence on voltage and manufacturer. But having studied this question in detail, I came to the conclusion that there is a great similarity between many data from datasheets from different manufacturers.
The logical question arose about the universal ESR table for standard aluminum capacitors.
An example of such a universal ESR table can be this one, which was found on the Internet.
Who has any opinions on this?
 

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Delta prime

Joined Nov 15, 2019
373
Hello, there :) if you are using for general purpose you need not worry aluminium electrolytic capacitors . If you are a designer of electronic circuits then you must consider equivalent series resistance (ESR) as a figure of merit. Wet’ aluminium electrolytic, or solid aluminium electrolytics,
Some capacitors are designed specifically for low-ESR, but manufacturers of aluminium electrolytic capacitors do not specify ESR consistently. The value at 25°C and 100kHz is commonly quoted, with a formula provided to calculate the value at the operating frequency. Some suppliers specify at 120Hz; others leave the designer to calculate the figure at the frequency of interest from the dissipation factor (tan∂) and specified maximum ripple current.
 

rsjsouza

Joined Apr 21, 2014
249
I rely on the manufacturer's datasheet, which never gives out ESR but instead tan δ, which varies wildly depending on the physical construction and the frequency.

Due to that, I personally wouldn't put much trust in a generic ESR table.

Interesting (and old) discussion about all this. Especially the posts from the user free_electron.

https://www.eevblog.com/forum/beginners/esr-meter/
 

Thread Starter

bob2

Joined Jun 15, 2019
180
I rely on the manufacturer's datasheet, which never gives out ESR but instead tan δ, which varies wildly depending on the physical construction and the frequency.

Due to that, I personally wouldn't put much trust in a generic ESR table.

Interesting (and old) discussion about all this. Especially the posts from the user free_electron.

https://www.eevblog.com/forum/beginners/esr-meter/
There are many discussions on this issue, and often the discussion participants have an absolutely opposite opinion.
With all due respect to calculations and formulas, the general ESR table is more practical in quickly assessing the state of a capacitor and its further use.
Therefore, the tables are glued to the front panel of the ESR meter or inserted into the firmware.
And most importantly, we need to calmly understand why in different tables the ESR values of capacitors differ significantly.
 

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DarthVolta

Joined Jan 27, 2015
477
Something I never do yet is check the datasheet. I have an LCR meter, and it can do a lot more than check ESR, but I'm not sure what works best either.
 

andrewmm

Joined Feb 25, 2011
399
re data sheets against an LCR meter.

A Random sample of one tells you nothing about the design.

If you want to use a LCR to check an individual capacitor, are you doing it at the frequencies you want to use, at the currents / voltages your using, at the same temperature ?

If not the results are telling you a lot less than is in the data sheet ,
 

Thread Starter

bob2

Joined Jun 15, 2019
180
In fact, the table is needed for a quick assessment of ESR for in-circuit measurement of capacitors.
When you have to check dozens of capacitors in a row when repairing electronic devices and you are limited in time, you do not have the opportunity to look for datasheets for each capacitor. Well, you can not always find it.
I sometimes use this large ESR table.
 

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Thread Starter

bob2

Joined Jun 15, 2019
180
re data sheets against an LCR meter.

A Random sample of one tells you nothing about the design.
There is a wide range for the application of the ESR table. For those who use the LCR meter and for those who service or repair electronic equipment.
 

rsjsouza

Joined Apr 21, 2014
249
With all due respect to calculations and formulas, the general ESR table is more practical
I disagree. The tan δ is a ratio between the reactance and the ESR, thus much simpler than having a full 2D table of capacitance and voltage values to compare. Using a LCR meter at the frequency of interest, you can simply put aside as relatively good anything that measures a tan δ below 0.1*. Everything else you put on a "suspect" pile and do additional verification against a known source (the datasheet, for example).

Sure, it is more "practical" in the sense you have more ESR meters out there that also feature a table stamped on the side, but you can never be absolutely sure of its real validity. My perspective comes from the fact that I have seen one too many good capacitors replaced due to cheap meters or incorrect tables.

(*) Higher for smaller voltage capacitors. Also, "relatively good" can mean a range of factors that are not accounted for - the major one being that LCR meters only go up to a few volts and normally quite far from the nominal voltage, which could reveal additional leakage and degradation.

A Random sample of one tells you nothing about the design.
I agree. An individual measurement compared against average values can lead to unnecessary replacements.
 

Thread Starter

bob2

Joined Jun 15, 2019
180
Using a LCR meter at the frequency of interest, you can simply put aside as relatively good anything that measures a tan δ below 0.1*.
Yes, but you must understand that in-circuit measurements are not very suitable for conventional LCR meters.
 

rsjsouza

Joined Apr 21, 2014
249
Yes, but you must understand that in-circuit measurements are not very suitable for conventional LCR meters.
Interesting; I don't recall the mention of in-circuit measurements here (did I miss anything?). I rarely (if ever) do tan δ in-circuit - I usually try to get a ballpark of capacitance in reservoir circuits.
 

Thread Starter

bob2

Joined Jun 15, 2019
180
We are talking about measuring different parameters.
You are talking about D, I'm talking about ESR. Both parameters show capacitor losses and their quality. But the advantage of ESR parameter is in-circuit measurements.
 

Thread Starter

bob2

Joined Jun 15, 2019
180
Here is another proof that people make some conclusions, not from their own experience, but from some false ideas about the effect of the magnitude of the test voltage.
https://www.eevblog.com/forum/beginners/uni-t-ut612-lcr-meter-and-testing-esr-in-circuit/
Here is what irformation I read somewhere on the Internet.
On a 4.7uF capacitor at 0.6V RMS, there will be a voltage of 150mV, and at 0.1V RMS, a voltage of 45mV.
On a 47uF capacitor at 0.6V RMS, there will be a voltage of 30mV, and at 0.1V RMS, a voltage of 9mV.
 
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andrewmm

Joined Feb 25, 2011
399
@bob2,
I wonder, could you post some links to how to use these tables to determine a good / bad capacitance please.
Its an interesting topic that I have not heard off.
 

Thread Starter

bob2

Joined Jun 15, 2019
180
@bob2,
I wonder, could you post some links to how to use these tables to determine a good / bad capacitance please.
Its an interesting topic that I have not heard off.
I have to upset you a little, but there are no such links and never have been.
There are many conversations, opinions and discussions. But there is no clear understanding of this issue.
A lot of information that has been thrown into the Internet space has no original sources.
And here should be the desire of the forum participants to create such an ESR table. There is no ready ESR table.
Here is an example of an ESR phantom table.
 

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Thread Starter

bob2

Joined Jun 15, 2019
180
On the example of this table, several problems are clearly visible(ESRTable1).
Test voltage.
This voltage should be as low as possible.. But here another problem arises. Measurement accuracy worsens. With a decrease in test voltage, some digital ESR meters deteriorate measurement accuracy. What does this mean? ESR meter instead of 0.01 Ohm can show 0.03 Ohm.
Accordingly, the bar of the maximum allowable ESR rises.
Measurement frequency. It also affects the result. The higher the frequency, the lower the ESR of the capacitor.
Measurement method. It also affects. For example, Bob Parker's ESR meter and many meters working on this method work on the principle where there is no fixed frequency. RLC tweezers, on the contrary, work at fixed frequencies.
Sometimes this difference can be quite significant for the measurement results and the decision on the further use of the capacitor.
 

Thread Starter

bob2

Joined Jun 15, 2019
180
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