LC/ESR meter - I'm confused and lost...

[ChildOfVision]

Hi!
I really don't want to start yet another thread about that theme, but I'm finally lost my nerves ! Either they are not cheap (must be DIY), or aren't precise enough or.... always some drawbacks !
So, please, if somebody knows for good DIY LC/ESR meter preferably in one instrument let me know! It must meet these requirements:
1) PIC or AVR based LC/ESR meter, 16x2 LCD;
2) Wide range measurements, especially in VERY LOW-inductivity range (it must have capability to measure a 1 turn-air-core inductor, or even small piece of copper wire, whether a low or high Q!) with fairly good resolution and tolerance;
3) simultaneous display of capacity and ESR (for out-of-circuit measurements) with at least 1 mΩ resolution and good precision;
4) at leats 1 mΩ resolution and good precision for in-circuit ESR measurements; (protection from charged capacitors in both cases!);
5) measuring internal resistance of batteries;
6) if possible, measuring parasitic capacity of an inductor;
7) must be built with easy-to-find parts (my main and only supplier (where I live) is Futurlec.com! Digikey, Mouser etc. are just a dream to me ! Please note: I'm on a VERY limited budget!

If you, guys, think that it is not possible, I would accept even two separate devices: precision LC meter and a good ESR meter! Has anyone tried to build THIS Russian ESR meter - has a resolution of 0.1 mΩ !!!, but I do not know the other specifications (page is on Russian)?
Also, what do you think about **broken link removed** LC meter (although it is not DIY): 1% accuracy (!?), C-Range(s): 0.01 pF to 100,000 uF, L-Range(s): 1 nH to 100H (!?) - too good to be true?

Thanks in advance to everyone, and sorry if I do not immediately respond to your replies (I'm going to sleep now)!

 

[ChildOfVision]

Nobody???

Then, PLEASE, let me know if somebody knows the source (documentation) for LC/ESR (I think) meter - I have attached a schematic of this device - I have no other information!

Also, if somebody know the link for this meter in this forum let me know - I can't find it with search.

TIA!

 

[Nigel Goodwin]

I would suggest your requirements are pretty impossible, particularly for a homemade device - I would suggest you reconsider what you need, rather than what you imagine you might need.

I would also suggest you look at the Peak range, small and reasonably priced, two of them should do most of what you want

https://www.peakelec.co.uk/acatalog/jz_instruments.html

 

[JimB]

especially in VERY LOW-inductivity range (it must have capability to measure a 1 turn-air-core inductor, or even small piece of copper wire, whether a low or high Q!) with fairly good resolution and tolerance;

Dream on baby!
Accurate measurement of low value inductors is not the sort of thing where I would use a PIC or any other microcontroller.
For such low values of inductance, you need to be considering resonance methods such as a Q meter working at high frequencies.

JimB

 

[ChildOfVision]

Thank you all for replies!
I said that it may be two separate instruments. Any suggestion appreciated!
But what you think about LC meter from my second link (from ebay) - to good to be true?

See you later!

 

[kiriakos-gr]

check this link to get some ideas..

https://www.eevblog.com/forum/index.php?topic=4476.0

 

[dtmf75]

my galery of esr meters )
**broken link removed**

 

[TULLIO]

ESR meter

Hello ChildOfVision, the best is here; ESR Meter Neo Teo (Spanish) Very complete, with PCB included.

 

[ChildOfVision]

First at all, sorry for delayed reply to your last messages, I didn't get notification!

So, kiriakos-gr thanks for link!

@TULLIO: thank you very much, but I prefer digital meters.

@dtmf75: your nick sounds familiar to me - are you famous DTMF from VRTP forum? Well, I just start to assemble that "Hungarian" LCM3 meter! Since I am not a member of VRTP (Ruslan is friend of mine btw.) maybe I can ask you about pot-core inductor, as I know you are using pot-core inductor in your version of LCM3? So, I somehow find one such core, but I don't know how to properly "use" it? The parameters are: outer diameter = 22mm (yes, I know, is it a little big), high of two halves together (in "working state") is 16mm. No air-gap! There is a hole through inner pillars of 5mm. It is very old Siemens & Halske 57T5 T26 X09 o.L. core. I don't have any info about T26 ferrite material. So, what do you mean, can I use it? If I wind it "multi-fillar" (litz-wire) like e.g. 7-strains - should I twist them, or just keep them together in a simplest way? Is the air-gap totally necessary? What should be a minimum and maximum diameter of each thread/strain (or allowable range)?

TIA!

 

[unclejed613]

way back when, we used to use a device called a "grid dip meter" (a solid state version called a "gate dip meter" exists also) to measure unknown inductances. you would attach a known capacitor to the inductor, then use the GDM to find the resonant frequency. once the frequency was known, along with the known capacitance, it was simple to calculate the unknown inductance.

https://www.electro-tech-online.com/custompdfs/2012/04/Gate_Dip_Meter_By_VU2PPP.pdf

 

[davenn]

way back when, we used to use a device called a "grid dip meter" (a solid state version called a "gate dip meter" exists also) to measure unknown inductances. you would attach a known capacitor to the inductor, then use the GDM to find the resonant frequency. once the frequency was known, along with the known capacitance, it was simple to calculate the unknown inductance.

https://www.electro-tech-online.com/custompdfs/2012/04/Gate_Dip_Meter_By_VU2PPP.pdf

Them were the days unclejed!! you would be struggling to find a ham shack that has a GDM (GDO) these days. And 90% of new hams wouldnt even know what one is or how to use it if given one!!


@ childofvision

7) must be built with easy-to-find parts (my main and only supplier (where I live) is Futurlec.com! Digikey, Mouser etc. are just a dream to me ! Please note: I'm on a VERY limited budget!

And exactly where do you live ?? no point in giving us a requirement without telling us what country you are in
And telling us you are on a VERY limited budget, knocks out probably 50% of your tester requirements

cheers
Dave

 

[ChildOfVision]

Hi to all!
Long time ago, when I was some 20 years younger, and much dumber than I am today, I found some "strange device" made on an old style bakelite-board with connections soldered with (a lot of) wires on rivets... It was some "Grid-dip meter" - what to hell is this? Of course, I disassembled poor device (for parts)! I still have some of those parts...

@davenn: (are you maybe legendary Dave from EEV-Blog?) - if I wanted to everybody knows details, I would put my real name and location, not nickname Child Of Vision - my favourite song from Supertramp! Well, lets say, I'm in the country with the most peculiar shaped borders in Europe!

Anyway, this thread is somewhat obsolete, I just assemble that Hungarian LCM3 meter - but now I have a question about pot-core addressed to dtmf75 as first, but if anybody else have some advice - please!

 

[dtmf75]

First at all, sorry for delayed reply to your last messages, I didn't get notification!

So, kiriakos-gr thanks for link!

@TULLIO: thank you very much, but I prefer digital meters.

@dtmf75: your nick sounds familiar to me - are you famous DTMF from VRTP forum? Well, I just start to assemble that "Hungarian" LCM3 meter! Since I am not a member of VRTP (Ruslan is friend of mine btw.) maybe I can ask you about pot-core inductor, as I know you are using pot-core inductor in your version of LCM3? So, I somehow find one such core, but I don't know how to properly "use" it? The parameters are: outer diameter = 22mm (yes, I know, is it a little big), high of two halves together (in "working state") is 16mm. No air-gap! There is a hole through inner pillars of 5mm. It is very old Siemens & Halske 57T5 T26 X09 o.L. core. I don't have any info about T26 ferrite material. So, what do you mean, can I use it? If I wind it "multi-fillar" (litz-wire) like e.g. 7-strains - should I twist them, or just keep them together in a simplest way? Is the air-gap totally necessary? What should be a minimum and maximum diameter of each thread/strain (or allowable range)?

TIA!

Hello, i use pot core only for experiments, because is very big and unstable. For my meter i use only factory made model DRH104R-stable,small and not bad: U esr 165 to 200 mV. Now i working to 2 in 1 version- ESR C L meter+ semiconductor tester. A made it with soic20/pic16+dip28 atmega, but i want ssop20+TQFP atmega becouse maybe in future i will made 3 in 1 version.

 

[ChildOfVision]

Thank you dtmf75, I saw your "2 in 1" - it looks very promising! My first thought was you've put some extra code into LCM3's PIC! Can that semiconductor tester work as a stand-alone device (I assume it is so, and you "just" swap shared LCD between PIC (LCM3) and semicon.tester (Atmega))? Do you maybe have some links to that tester? And, what about firmware and source code? Are these "open"?

 

[dtmf75]

Hex file is free.
Check there-original German site:
https://www.mikrocontroller.net/articles/AVR-Transistortester
In Rusian:
https://vrtp.ru/index.php?showtopic=16451

 

[ChildOfVision]

Thanks! It is really simple design!