Author Topic: ESR Meter Adapter Design and Construction  (Read 163324 times)

0 Members and 1 Guest are viewing this topic.

Offline Jay_Diddy_BTopic starter

  • Super Contributor
  • ***
  • Posts: 2731
  • Country: ca
Re: ESR Meter Adapter Design and Construction
« Reply #75 on: January 21, 2014, 12:19:52 am »
Hi group,

Time for another update. My PCBs arrived today from itead.

Solder Paste Stencil

The first job was to make a solder paste stencil. I started with an aluminium pop can. I cut out the side wall with a pair of scissors and flattened it:




I taped the aluminium sheet to a scrap piece of 0.062" FR4 on the bed of my circuit board router:





I have previously made a file from the top solder paste layer.

Here you can see the stencil being cut:



After the stencil was finished, I made a simple fixture to hold the board while I applied the solder paste. The fixture was made by taping scrap pieces of copper clad board together:



Assembly

After I applied the solder paste, I manually placed all components using tweezers. I then had four boards ready for reflow in a toaster oven. I don't have a reflow controller. I use a Fluke 52 thermocouple thermometer and a watch to set the soldering profile.



Here is the finished board:



And the board mounted on the box. The box in the picture is a Hammond 1591LGY.




I did a quick check and this works like prototype.
Here is the final version of the schematic:



I have also attached a pdf version of the schematic.

Jay_Diddy_B




« Last Edit: January 21, 2014, 12:28:05 am by Jay_Diddy_B »
 
The following users thanked this post: mixiom

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7547
  • Country: 00
  • +++ ATH1
Re: ESR Meter Adapter Design and Construction
« Reply #76 on: January 21, 2014, 01:52:16 am »
+1 and thanks for sharing, look great.  :-+

Edit : What is that R21 used for ?
« Last Edit: January 21, 2014, 02:08:18 am by BravoV »
 

Offline robrenz

  • Super Contributor
  • ***
  • Posts: 3035
  • Country: us
  • Real Machinist, Wannabe EE
Re: ESR Meter Adapter Design and Construction
« Reply #77 on: January 21, 2014, 02:47:12 am »
Very nice work  :-+

Offline Jay_Diddy_BTopic starter

  • Super Contributor
  • ***
  • Posts: 2731
  • Country: ca
Re: ESR Meter Adapter Design and Construction
« Reply #78 on: January 21, 2014, 02:56:23 am »

Edit : What is that R21 used for ?

R21 is a zero ohm resistor. It was used to jump over a track so that the layout doesn't have any vias and no traces on the top side of board. The top side of the board is the front panel.

I played around with the layout for a long time, but I just could not work around having the one zero ohm resistor.

Jay_Diddy_B
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7547
  • Country: 00
  • +++ ATH1
Re: ESR Meter Adapter Design and Construction
« Reply #79 on: January 21, 2014, 03:01:03 am »
Ahh.. got it.  ;D

Also curious on the 2W vs 4W results from these boards, any significant differences ?

Offline oldway

  • Super Contributor
  • ***
  • !
  • Posts: 2172
Re: ESR Meter Adapter Design and Construction
« Reply #80 on: January 21, 2014, 07:44:17 am »
Simple, cheap, very well protected, it's a very nice project.
Thank you very much for sharing. :-+ :-+
« Last Edit: January 21, 2014, 07:47:08 am by oldway »
 

Offline Jay_Diddy_BTopic starter

  • Super Contributor
  • ***
  • Posts: 2731
  • Country: ca
Re: ESR Meter Adapter Design and Construction
« Reply #81 on: January 22, 2014, 03:45:44 am »
Ahh.. got it.  ;D

Also curious on the 2W vs 4W results from these boards, any significant differences ?

BravoV asked, so I did some tests. :-DMM

I first measured some capacitors on an HP 4274A LCR (Z) meter. The ESR adapter was zeroed before each test using the relative button on the DMM.

4.7uF 50V measured ESR 1.28 Ohm


Measurement with short leads approximately 4 inch (10cm)

2W 1.25 Ohm

4W 1.22 Ohm

Measurement with medium leads approximately 18 inches (45cm)

2W 1.36 Ohm

4W 1.23 Ohm



1000uF 35V 105C  70 mOhm

Measurement with short leads approximately 4 inch (10cm)

2W 79 mOhm

4W 70 mOhm

Measurement with medium leads approximately 18 inches (45cm)

2W 87 mOhm

4W 80 mOhm


So the answer is not that much.

For trouble-shooting I would use 2W long leads.

For more accurate measurements I would use 4W short leads.

For really accurate measurements I would use my LCR meter. I would not use my LCR meter for trouble-shooting because it lacks adequate protection.

Jay_Diddy_B


 
The following users thanked this post: mixiom

Offline jaxbird

  • Frequent Contributor
  • **
  • Posts: 778
  • Country: 00
Re: ESR Meter Adapter Design and Construction
« Reply #82 on: January 22, 2014, 04:27:17 am »
It looks really great  :-+ Simple and beautiful design.

Love the diet Pepsi stencil, although, personally, I would probably have used diet Coke instead :)


Analog Discovery Projects: http://www.thestuffmade.com
Youtube random project videos: https://www.youtube.com/user/TheStuffMade
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7547
  • Country: 00
  • +++ ATH1
Re: ESR Meter Adapter Design and Construction
« Reply #83 on: January 22, 2014, 05:48:39 am »
Jay_Diddy_B, thank you so much for the efforts, results look very impressive compared to that thousand dollars LCR meter !  :-+

Offline SuperHerman

  • Newbie
  • Posts: 4
Re: ESR Meter Adapter Design and Construction
« Reply #84 on: January 24, 2014, 01:01:49 am »
Hi,
i was following this thread with great interest and decided to build an esr meter, because i liked the idea of cutting out the inductive voltage spikes i decided to build a version similar to oldboys last design. Being only a prototype i didnt bother to make a pcb but just started building the circuit on a copper clad board. At the moment i am still testing the thing but it seems to work fine, it has a full range of only 4.2 Ohms but that is ok for an esr meter because when a cap has an esr higher than that i do not really care how high anyway. It works good to below 10µF, and a 150nF Cap still reads slightly over 1 Ohm ( the orange one in the picture ).

The resistors i measured in the pictures are:
1 Ohm 10% --> 1,018 Ohm --- i measured this Resistor to 1,014 Ohms with another meter
3,3 Ohm 10% --> 3.347 Ohm --- measured this one to 3.347 Ohm and calibrated the esr meter with it
0.062 Ohm 10% --> 0.061 Ohm
0,180 Ohm 10% --> 0,184 Ohm
0,120 Ohm  ?% --> 0,119 Ohm

The resolution and accuracy of this design could be increased by using a precision voltage reference (i rely on the ouput of the LM7810 i use)
and not using cd4066 as a switch, but i like the results and will use it in the future. Usually when repairing stuff i don't rely on esr measurement anyway but look at the voltage across the elkos with a scope to see if they are good, but for quick measurements a reliable esr meter is a good thing to have, so it will suffice for my needs.


« Last Edit: January 24, 2014, 01:11:42 am by SuperHerman »
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7547
  • Country: 00
  • +++ ATH1
Re: ESR Meter Adapter Design and Construction
« Reply #85 on: January 24, 2014, 02:46:33 am »
SuperHerman, thanks for sharing, the results look impressive !  :clap:

Btw, curious on that BNC connector, what is that for ? For scope measurement point ? or external pulse generator ?


...i decided to build a version similar to oldboys last design.
You mean oldboys oldway's circuit ? -> Oldway's variant @ post #75


...and not using cd4066 as a switch...
So what are you using for the switch ? 4053 ?


Talking about the switches, I know the results so far are "more than enough", just purely academical here, will there be any significant difference when using HCT4053 vs HCT4066 ?
« Last Edit: January 24, 2014, 03:16:09 am by BravoV »
 

Offline SuperHerman

  • Newbie
  • Posts: 4
Re: ESR Meter Adapter Design and Construction
« Reply #86 on: January 24, 2014, 04:23:55 am »
Sorry for the name fail on my part oldway, :palm:,

The BNC connector is part of the 4 wire measurement, the 2 twisted cables provide the current to the DUT and the coax cable conducts the signal back.
I do use the 4066, but i think it is not an optimal device to switch the current to the DUT due to the relative high internal resistance and its tempco. If i would do it again i would use 2 complementary fets or some other way to provide  a more precise and stable current like maybe an improved howland current source, but it is not really important for an esr meter to be highly precise, so it would be more an academic question. At the moment the offset drift is the biggest error, it changes up to 5mV at the output until everything reaches thermal equilibrium, i used 2 op177, one as a buffer and the other as a differential amp with a gain of 100 and 0.1% resistors (only around the x100 amp) with low tempco of 20ppm/°C  if i remember correctly. Offset correction is done only at the buffer amp. I don't know yet where the offset drift comes from, but part of it comes surely from the opamps.
Greetings
 

Offline Jay_Diddy_BTopic starter

  • Super Contributor
  • ***
  • Posts: 2731
  • Country: ca
Re: ESR Meter Adapter Design and Construction
« Reply #87 on: January 24, 2014, 04:58:29 am »
SuperHerman,

You have got excellent results !!

Can you post a schematic of your amplifier configuration?

The offset and the temperature coefficient of the offset will be amplified by the gain of the amplifier. So if you are seeing a 5mV change at the output of the op-amp this would be a 50uV change when referenced back to the input. So this is inline with the op-amp specifications.

I would not worry too much. If you test a small capacitor like 4.7uF 50V and warm the capacitor with your fingers the ESR will drift a lot.

The same switches are used in the source as the detector to match the propagation delays. In my configuration I have a spare 1/3 of the 4053 which I could connect in parallel with the one in the source. I didn't do this because I wanted a single sided layout.

I explored the effects of delays in this message:

https://www.eevblog.com/forum/projects/esr-meter-adapter-design-and-construction/msg344453/#msg344453



The switch resistance is typically 80 Ohms, this in series with 470 + 1600 + 200 =2270 (assuming the pot is in the centre). So if the switch resistance changes by 40 Ohms the current will change by less than 2%. For the intended purpose, finding bad capacitors, this is academic.

Jay_Diddy_B
 

Offline jaxbird

  • Frequent Contributor
  • **
  • Posts: 778
  • Country: 00
Re: ESR Meter Adapter Design and Construction
« Reply #88 on: February 17, 2014, 11:28:19 pm »
I am now the happy owner of one of these nice boards:




I know it was designed for a specific box, but having a 3D printer, I enjoy making small boxes for projects, so this is what I came up with:




Made a couple of short Kelvin(ish) cables for it:




It works really well, big  :-+ to Jay_Diddy_B for the nice ESR meter adapter design.

Analog Discovery Projects: http://www.thestuffmade.com
Youtube random project videos: https://www.youtube.com/user/TheStuffMade
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7547
  • Country: 00
  • +++ ATH1
Re: ESR Meter Adapter Design and Construction
« Reply #89 on: February 18, 2014, 01:46:45 am »
Nice enclosure, love the way you made the room for that 9 V battery.  :-+

Hmm... torque screws.  8)
« Last Edit: February 18, 2014, 02:04:26 am by BravoV »
 

Offline jaxbird

  • Frequent Contributor
  • **
  • Posts: 778
  • Country: 00
Re: ESR Meter Adapter Design and Construction
« Reply #90 on: February 19, 2014, 03:51:13 am »
Nice enclosure, love the way you made the room for that 9 V battery.  :-+

Hmm... torque screws.  8)

Thanks :) .. I was thinking about how to avoid having the battery short the backside of the board and make sure the bananas wouldn't touch the battery, so I thought better make a separate compartment. Also prevents any battery leaks from ruining the device.

A cool board needs cool screws :D


Analog Discovery Projects: http://www.thestuffmade.com
Youtube random project videos: https://www.youtube.com/user/TheStuffMade
 

Offline oldway

  • Super Contributor
  • ***
  • !
  • Posts: 2172
Re: ESR Meter Adapter Design and Construction
« Reply #91 on: February 19, 2014, 10:40:28 am »
My ESD tester works well.
Thank you to Jay_Diddy_B !

I made some changes: (see diagram ESR3)
- Test frequencies of 100 kHz and 10 Khz
- Only 2W...4W is not practical for such an ESD tester.
- Offset and the resistance of test cables are compensated  by setting to zero with a 20K potentiometer. It's no longer needed to use the "relative function" of the multimeter. (cheap 5 bucks multimeter can be used )
-choice of easy to buy and low cost components.
- fully protected to 100V (seems to be enough)
The PCB is single sided and the components are SMD.
Only one jumper was needed.
Consumption is about 7 mA.

I'am preparing a more sophisticated version without problem of delay and two ranges, one from 0 to 20R and a more accurate one from 0 to 2R. (see diagram)
« Last Edit: February 20, 2014, 09:20:59 am by oldway »
 
The following users thanked this post: mixiom, Frankentronics

Offline astra

  • Contributor
  • Posts: 16
  • Country: it
Re: ESR Meter Adapter Design and Construction
« Reply #92 on: February 19, 2014, 11:53:50 pm »
Thank you all of you for the time you dedicate in sharing this useful projects..!
astra.
per aspera ad astra..
 

Offline TorqueRanger

  • Frequent Contributor
  • **
  • Posts: 331
  • Country: us
Re: ESR Meter Adapter Design and Construction
« Reply #93 on: February 20, 2014, 01:17:50 am »
How anyone used this design and whats the best design? ???


Thanks
Jason Sr
My ESD tester works well.
Thank you to Jay_Diddy_B !

I made some changes: (see diagram ESR3)
- Test frequencies of 100 kHz and 10 Khz
- Only 2W...4W is not practical for such an ESD tester.
- Offset and the resistance of test cables are compensated  by setting to zero with a 20K potentiometer. It's no longer needed to use the "relative function" of the multimeter. (cheap 5 bucks multimeter can be used )
-choice of easy to buy and low cost components.
- fully protected to 100V (seems to be enough)
The PCB is single sided and the components are SMD.
Only one jumper was needed.
Consumption is about 7 mA.

I'am preparing a more sophisticated version without problem of delay and two ranges, one from 0 to 20R and a more accurate one from 0 to 2R. (see diagram)


« Last Edit: February 20, 2014, 01:21:46 am by TorqueRanger »
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7547
  • Country: 00
  • +++ ATH1
Re: ESR Meter Adapter Design and Construction
« Reply #94 on: February 20, 2014, 04:02:56 am »
My ESD tester works well.
Thank you to Jay_Diddy_B !

I made some changes: (see diagram ESR3)
- Test frequencies of 100 kHz and 10 Khz
- Only 2W...4W is not practical for such an ESD tester.
- Offset and the resistance of test cables are compensated  by setting to zero with a 20K potentiometer. It's no longer needed to use the "relative function" of the multimeter. (cheap 5 bucks multimeter can be used )
-choice of easy to buy and low cost components.
- fully protected to 100V (seems to be enough)
The PCB is single sided and the components are SMD.
Only one jumper was needed.
Consumption is about 7 mA.

I'am preparing a more sophisticated version without problem of delay and two ranges, one from 0 to 20R and a more accurate one from 0 to 2R. (see diagram)

Thanks oldway, glad to see JDB's base design is evolving into another flavours.  :-+

Whats the difference between esr3 vs esr4 ?

Btw, the attached schematics esr3 and 4 appear to be blurry, am I the only one who experience this ?
« Last Edit: February 20, 2014, 04:05:56 am by BravoV »
 

Offline kripton2035

  • Super Contributor
  • ***
  • Posts: 2572
  • Country: fr
    • kripton2035 schematics repository
Re: ESR Meter Adapter Design and Construction
« Reply #95 on: February 20, 2014, 07:13:13 am »
a bit blurry for me too, must be the software that generated blurred jpegs
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7547
  • Country: 00
  • +++ ATH1
Re: ESR Meter Adapter Design and Construction
« Reply #96 on: February 20, 2014, 07:18:21 am »
a bit blurry for me too, must be the software that generated blurred jpegs

Ok, then I'm not alone.

To oldway, for electronic schematic, its better to save in lossles format PNG instead of lossy JPG, sometimes it will get even higher compression level than JPG with high compression setting.

JPG is suitable only for photograph real life images, for "cartoon" like image with much less color gradient and sometimes less color counts, use PNG.

Offline oldway

  • Super Contributor
  • ***
  • !
  • Posts: 2172
Re: ESR Meter Adapter Design and Construction
« Reply #97 on: February 20, 2014, 10:04:32 am »
Thank for your comments.

- I modified my previous post and replaced the JPG by PNG pics.

- I noticed a problem with the original project: voltages on the 2 capacitors C11 and C12 of my ESR3 diagram should be symetrical (one + and the other -) in reference with AGND.
This is not happening: voltages are drifting at an average value far from AGND.
I realized that the reason of this is because there is no AGND reference in that circuit and that this is a high impedance "floating" circuit.
If there is a little difference between the positive and negative synchroneous rectifiers, this generate a DC voltage and a drift .
For this reason, I added the 2 resistors R1 and R27 of 10K in parallel with the capacitors C11 and C12.
As my version must be calibrated with R32, those resistors have no influence on the precision of the reading.

- "Difference between ESR3 and ESR4 ?"

1)Delays of the analoge switches causes some lack of precision.
Jay_Diddy_B reduced this by choosing fast analog switches.
ESR4 is another approach to solve this problem by reducing (of a symetrical manner) de conducting angle of the synchroneous rectifiers to 150° instead of 180°.
This is made by the comparator LM311.
2) I added a 10x gain OP amp so we have two ranges: 0-20R (reading: 1V = 10R) and 0-2R (reading 1V = 1R). The last one seems easier to use.
3) I modified the power supply, using the original project of Jay_Diddy_B for two reasons:
- I was spilling 1mA consumption only for the TL431, this is nonsense.
- I needed to free an OP amp of the LM324 for de 10x gain amplifier.

« Last Edit: February 20, 2014, 10:08:47 am by oldway »
 
The following users thanked this post: mixiom

Offline kripton2035

  • Super Contributor
  • ***
  • Posts: 2572
  • Country: fr
    • kripton2035 schematics repository
Re: ESR Meter Adapter Design and Construction
« Reply #98 on: February 20, 2014, 12:07:50 pm »
the png are still blurried ... but it's still readable not a big problem.
 

Offline neslekkim

  • Super Contributor
  • ***
  • Posts: 1305
  • Country: no
Re: ESR Meter Adapter Design and Construction
« Reply #99 on: February 20, 2014, 01:18:38 pm »
the png are still blurried ... but it's still readable not a big problem.

Check your glasses, or clean your screen :), the png's are not blurry at all, no compression artifacts at all.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf