East Tester ET4410 ESR Measure

[TimFox]

Since you are approaching self-resonance at 100 kHz, the measured reactance/capacitance will depend on the lead length in your fixture.
It only takes 2.5 nH to resonate 1000 uF at 100 kHz.

[The Electrician]

For those of us without a nice Hioki IM3570 we can generate some decent plots of DUT Capacitance Impedance Magnitude and Phase with a scope and signal generator. Simply sweeping the source frequency over the desired range and measuring the amplitude and phase of the voltage across across the DUT and current thru the can yield the result with a little math.

Here as some plots done on the IM3570, with colors set to match yours.

One thing that your plots aren't getting right at the extreme frequencies.  The phase curve vs frequency should be monotonic.

The first one is of a 1000 uF cap of moderate loss:



Here is a plot of another 1000 uF cap with lower loss.  You can see the effect of lower loss; the curvature of the bottom of the |Z| curve is more rapid the lower the loss:



Here are both plots superimposed:

[The Electrician]

So...
Today I´ve measured the both panasonic caps at work again, the menu of the ST2830 is not the clearest one.
A few minutes ago I did the same again at home on the ET4410, to have it all in one post.

The 100µ cap at 120Hz:

ST2830                  ET4410
103.16µF               103.33µF
Xc -12.86 Ohm      -12.84 Ohm
Q 51.10                  51.80
D 0.0196                0.0192
ESR  0.252 Ohm      0.250 Ohm
Phase -88.88°          -88.89°

At 100Khz:

26.50µF                  15.40µF
-0.071  Ohm            -0.104 Ohm
1.607                      2.427
0.6185                    0.4115
0.038 Ohm              0.043 Ohm
-57.86°                   -67.63°

1000µF at 120Hz

ST2830                  ET4410
945.91µF                946.8µF
Xc -1.402 Ohm       -1.401 Ohm
Q 28.60                  29.04
D 0.035                  0.035
ESR 0.049 Ohm       0.048 Ohm
Phase -87.99°         -88.03°

At 100Khz

72.50µF                  23.80µF
-0.025 Ohm             -0.067 Ohm
1.578                      3.756
0.632                      0.266
0.014 Ohm              0.018 Ohm
-57.31°                  -75.20°

At 120Hz they are like twins..

Datasheets:
1000µF/25V FM Type:
https://www.micro-semiconductor.com/datasheet/37-EEU-FM1E331LB.pdf

100µF/35V FR Type:
https://industrial.panasonic.com/cdbs/www-data/pdf/RDF0000/ABA0000C1259.pdf

Martin72,

Would you please post a photograph of the fixturing or Kelvin cable you are using to make measurements of your ET4410 and the meter at work?

[mawyatt]

One thing that your plots aren't getting right at the extreme frequencies.  The phase curve vs frequency should be monotonic.

That's due to the setup fixturing or lack thereof, just a Proto-Board, Scope Probes, 1K 2W leaded resistor and 1 Meter BNC to Clip lead cable, unterminated. No attempt was made to keep things short and proper for RF type frequencies, just a quick test to show how the DSO can implement a nice Impedance Plot with the help of the Bode Function. Also didn't change the scope input channels to 200MHz or full BW from 20MHz BW which probably should have done. Also should add, that the DUT "sees" the source 1K Resistor which affects the low frequency response.

Best,

[The Electrician]

I figured there were reasons, related to the likelihood that you hadn't made a major project out of it!

[mawyatt]

Yep, just a quick setup and test. Here's couple of plots for a 100uF and 10uF Polymer types, they agree with TH2830 as 95.19 (97.73uF) @ 100Hz and 9.16 (9.76uF) at 1KHz. Note these plots only go to 1MHz to stay within reason for the kludge setup involved.

If Siglent is "listening", this has demonstrated that the SDSX + and even better SDSX HD are capable of generating useful Impedance Plots. If they had the ability to plot a Resistance scaled Y axis then the display would be in dB ohms, and with the ability to do a short open calibration and utilize such in the display. Add to this the ability to "plot" various computed parameters (C, Z, Y, D, Q, ESR) within the Bode Function, well you see where we are going 

With this we could add a quality test fixture with selectable ranges (we know how to do this!!) and you now have a wideband Impedance Analyzer of decent performance 

Maybe Siglent is listening

Best,

[Martin72]

Martin72,

Would you please post a photograph of the fixturing or Kelvin cable you are using to make measurements of your ET4410 and the meter at work?

Hi,

Did it, the last measures were all taken with the kelvin cables.
Then I remember I got the fixture also and repeated the 100Khz measure today at work and at home.
Will do a little table with the results of yesterday and today, post it when finished.
There are remarkable differences between fixture and cable.

Martin

[The Electrician]

Martin72,

Would you please post a photograph of the fixturing or Kelvin cable you are using to make measurements of your ET4410 and the meter at work?

Hi,

Did it, the last measures were all taken with the kelvin cables.
Then I remember I got the fixture also and repeated the 100Khz measure today at work and at home.
Will do a little table with the results of yesterday and today, post it when finished.
There are remarkable differences between fixture and cable.

Martin

I had just about decided that your unusual measurements were due to using cables.  Can you make measurements on the Panasonic 1000 uF cap at 120 Hz, 10 kHz and 100 kHz on both the ET4410 and at work on the ST, using the fixture?

[Martin72]

Can do.
"Unsual"...I guess you mean the 100khz measures, at 120hz both measure the same.
(For other readers who ecventually wondered why I use only the ET4410 and the ST2830, the keyysight handheld LCR, expensive and calibrated, measures on 100khz complete BS)

[indman]

They look this: https://www.ebay.com/itm/193196126203?hash=item2cfb62effb:g:FLgAAOSwZL5dwu1n
but mine are .5 uF

Thank you, these are very high quality styroflex (polystyrene) K71-7 capacitors. I keep them in a separate box, but I don't have the 0.5uF rating. I took a slightly lower value of 0.15uF for comparison and the results on the DE-5000 are very close to yours from post #68. I have shown in the screenshots the results of measurements using the software Hand-Held LCR for De-5000 at 1kHz and 10kHz. These pictures show that the DE-5000 can display more useful information than it has on the display and more high resolution for Q,D and other. ESR(Rs) at 1kHz is very unstable and fluctuates a lot, so I only showed 10 and 100kHz.

These two meters are quite a bit more expensive than the DE5000, but they perform much better.  The DE5000 performance is not bad for $100, but isn't there some old saying about getting what you pay for?

Everything is relative in this world, right? For me, $100 is not such a small amount. I have a Chinese LCR XJW01 with a price of $30 and I would not say that it is 3 times worse than the DE-5000. I also have an LCR measuring attachment with a computer sound card, which in Zmeter can draw similar Bode graphs and almost for free. Yes, there is a limit on the upper limiting frequency of 10-20 kHz. Therefore, if I buy an ET4410, which is 3 times more expensive than a DE-5000, this again does not mean that I will have a meter 3 times better in quality.

[The Electrician]

Martin72, have you had a chance to make measurements of the Panasonic 1000 uF electrolytic?   If so, please share your results with us.

[Martin72]

Hi,

Yes I had...
Yesterday made measurements on the ST2830 at work and with the fixture, then the same at home with the ET4410.
At 120Hz, 1Khz, 10Khz and 100Khz.
Also the 100µF Panasonic.
Values will come, probably in the next hours..

[Martin72]

Table...
Blue are the measures from the ET4410.
All measures with the fixture, when I got time I´ll make another table with the measures taken from them with kelvin clips.

Martin

[The Electrician]

Can the ST2830 set the frequency to frequencies other than the standard 100, 120, 1k, 10k and 100k?

Can your ET4410 do frequencies other than the standard 100, 120, 1k, 10k and 100k?

[mawyatt]

Martin has indicated that the ST2830 is a rebadged TH2830, and if so our TH2830 can be set to any frequency within 50Hz to 100KHz with sub Hz resolution at lower frequencies, and 1Hz resolution at 100KHz. So highly likely a DDS based signal source.

Best,

[Martin72]

@The Electrician:
Yes and yes...

ET4410 got 16(20 are mentioned in the spec) steps between 100Hz and 100khz.

ST2830 got 34 steps between 50hz and 100Khz.

What I´ve saw after buying the ET4410:
ET4510 allows free choosable frequencies with 1Hz resolution..
Here a snip from the manual, which frequency fits in the accuracy spec.

@mawyatt:

TH and ST are absolut the same and while I´ve searched the china stores for LCRs, some remarkable thing comes up.
In several cases, when you buy more, you can give the LCR your own name...
Edit: added ST2830 frequencies

[mawyatt]

@Martin,

Our TH2830 can be set to any frequency between 50Hz and 100KHz. Just connected the LCR probes to a counter and typed in 10.123KHz and got 10.122889KHz, then entered 51.987Hz and got 51.986334Hz, then entered 87.654KHz and got 87.653044KHz, 99.999KHz and got 99.997911KHz, then 99.999Hz and got 99.997995Hz. That's why I indicated this is using a DDS for the signal generation.

This must be an "undocumented" feature, as you enter the desired frequency using the "inc" and "dec" keys you step thru the predefined frequencies as you expect from the spec sheet.

However, if you use the keypad the screen will turn RED for the frequency display, even if you hit "Enter", but if you select Hz, KHz it accepts the input (as long as KHz is less than 100, and Hz is greater than 50), screen turns blue and the LCR meter outputs the desired frequency

If you try MHz the meter beeps and displays a RED Out of Range Error message, same with above for <50Hz or >100KHz.

So it seems that the TH2830 can implement just about any frequency between 50Hz and 100KHz even tho the specs indicate NOT 

I'll wager a brew that your ST2830 can do the same if you use the keypad technique described above

Know Thomas has a TH2830, hopefully he will spot this and give it a try!!!

BTW, the DDS is likely be big cost saving difference between the ET4410 and the TH2830.

Best,

[Martin72]

Interesting, will try this on monday 

BTW trying, It think I will test the pansonic caps on the scope like you did.

[mawyatt]

Use the Diff Amp technique if you have one. TopQuark also has an HD and has produced some stunning plots of various capacitor parameters with his Python routine which collects data from the HD Bode Plot, does some calculations and creates the plots.

Try and keep the setup tight for good results, we've run all sorts of caps from Electrolytics, Polymers, Mylar, Polypropylene, ceramic and even some inductors. The technique works well and is great for showing resonances and minimum impedances, much much better than a display number. Sure it's not as accurate as a proper LCR meter like your ET4410, and requires much more thought in usage.....Read NOT Plug-in-Play!!

However, a graph of impedance vs. frequency really shows when a device doesn't behave like a simple C, or L or R and shows where it begins to misbehave!! Since you have the tools for both, you should be all setup and ready

Best,

[The Electrician]

Interesting, will try this on monday 

BTW trying, It think I will test the pansonic caps on the scope like you did.

Do you have any 1000 uF electrolytics other than the Panasonic one we've been measuring so far?  Do you have any other caps with capacitance slightly larger than 1000 uF, such as some 1500 uF, 1800 uF or 2200 uF?

You shouldn't be getting a phase near -90 degrees at 100 kHz with a 1000 uF cap.  It would be good if we could figure why you're getting this result.

[mawyatt]

Don't have anything larger than 1000uF. Here's Beryl RC016M 1000uF @ 16V and a APAQ Tech Polymer EPZ40 1000uF @ 6.3V using the technique with R = 1K shown here:

https://www.eevblog.com/forum/testgear/capacitive-impedance-plots-with-sds2104x-plus-bode-function/

Edit: Changed the plots to use R =100 (more test current) and moved cursor to 100KHz. I wouldn't put too much faith into these plots at higher frequencies as the kludge test setup is influencing the results.

Best,

[Martin72]

Absolutely and this is why I´m doing this thing here.
To find out what´s going on.
The circuit design of the ET4410 is not bad, not simple(actually) and have an advantage against LCRs with chipset like DE5000, it´s "discrete"..
I must have a look in my "store" if there are caps here over 1000µ, otherwise I connect several together.

[The Electrician]

It would be good to have a curve of phase and capacitance vs. frequency.  The ST2830 (rebadged Tonghui) has just the right intermediate frequencies--ten of them per decade.  Taking measurements at all those frequencies will be somewhat tedious, but we will learn much from such curves.

The old fashioned way is to plot points on a sheet of log-log paper.  Nowadays you could use Excel or some other plotting program to produce the curves (logarithmic on both axes).  The idea is to get curves that look like the green curves in the first image of reply #123 and the green curve of reply #126.

Here is what a plot of capacitance vs. frequency for a 1000 uF cap should look like.  Notice how the capacitance decreases as frequency increases until a minimum is reached.  Then as the frequency continues to increase, the capacitance begins to increase as we approach the self resonance frequency.  When we pass the SRF, the impedance becomes inductive rather than capacitive, and the green curve has a discontinuity and goes negative, off the bottom of the screen.

[Martin72]

The ET4410 got a "list" function, where you can determine measure steps with different testfrequencies and let it run.
Problem 1 : It got only 7 steps.
Problem 2: will function fine when choosing a main parameter like Capacity, sub-parameters are some kind of buggy.
But it got also scpi functionality, so you could create graphs using the interface and a suitable script/program.
But with 16 testfrequencies, resolution would be poor.
Therefore (not only) I´m playing hard with the thoughts to get the ET4510.
It got "endless" testfrequencies between 100Hz and 100khz in 1hz steps.
The rest should be the same.

[mawyatt]

Might also check the Th2830. We got ours from Beich here. Make sure you get confirmation they will honor warranty.

https://www.aliexpress.com/item/2261799944889907.html?spm=a2g0o.productlist.0.0.359533bf8sKzAb&algo_pvid=8188e631-20c5-4a39-8843-e3c406bea52f&algo_exp_id=8188e631-20c5-4a39-8843-e3c406bea52f-1&pdp_ext_f=%7B%22sku_id%22%3A%2220000000125229728%22%7D&pdp_npi=2%40dis%21USD%21850.0%21850.0%21%21%21%21%21%40210318b916599065824813386eb34a%2120000000125229728%21sea&curPageLogUid=liLHRYVUMC3e

Best,