An awesome ZLCR meter - Page 2

Radioman62 · 10th September 2010, 10:26 PM

Elvee
You refer to .. as it seems interresting links but the languish problem persist. I will try with google translate and let you know if I went happy about the information

je suis a room avec douche silvoplait

Have fun!

Elvee · 11th September 2010, 06:58 AM

Sorry, I have no idea about the identity of your guy at MW.

For the projects, the text is in french, but schematics and pictures are universal. Of course, there is always the risk to miss a small detail, just as I did.

zdr · 11th September 2010, 06:10 PM

I build mine with Lm833 (burnt my only lm358 as there is a blunt error in ps polarity on the web page), and finally made it work, running on single 9V PS with virtual ground. I have ridiculous errors of around 20-50% at 1KHz, for 100ohm range (0.82mH reported as 0.99, 3.9 ohm as 5.6, etc). Some serious issues with app not entering calibration mode, then getting stuck in calibration mode, and so on...

Starting to remind me of speaker workshop on which I wasted a good week before I threw it away together with it's jig.

I hope I am missing something as usual

What do you guys use as PS? Which version you built?

zdr · 11th September 2010, 06:28 PM

Actually, I swapped back my supposedly dead LM358, and guess what - not only that is not dead, but also measured my 0.82mH coil as 0.8224mH

I guess we all better stick with the recipe and use LM358 as specified by author. Digits are also quite calm... Back to more testin'

Elvee · 11th September 2010, 06:58 PM

Quote:

Originally Posted by zdr

Actually, I swapped back my supposedly dead LM358, and guess what - not only that is not dead, but also measured my 0.82mH coil as 0.8224mH

I guess we all better stick with the recipe and use LM358 as specified by author. Digits are also quite calm... Back to more testin'

In this case, I think i'll give a try to a LM324, instead of the TL074.
For 1KHz, anyway, shouldn't change anything.
With a high averaging value, it's OK for the main parameter, but the minor parameters are not filtered, and a good hardware stability would certainly be helpful.

zdr · 12th September 2010, 09:51 PM

I just could not make it work properly with my SB Audigy, running on KX Drivers. It was off 4 times just by switching range... But, with built in SoundMax, works like a charm, quite consistent. If I measure 3.3uF with 100 ohm then switch to 1000 ohm with same DUT, it's off by 0.02uF; but, that could be due to measurement resistor tolerance, so I ordered some 0.01% resistors to replace 1% ones. I wonder how much they influence overall accuracy...

I cannot compare to any stock meter, but it seems to be quite accurate. Finally a good, working and cheap LCR meter

Andrew Eckhardt · 10:59 PM

Must be lots of interest in this one. The site was quite slow a while ago.

I slapped together an L meter for speaker range inductances. Not nearly the same league as this, but it fits in a tiny box somewhere near your DVM.

I got the idea from here:

Inductance Meter Circuit | Circuit Diagram

The "major" drawback is the test frequency and waveshape, but can probably get you within of a few percent of the number you want in any case. Pretty easily 1% if you're winding or modifying air core inductors.

The inverters can all be from one hex package, they're only different because I don't always use ltspice right.

Andrew Eckhardt · 12th September 2010, 11:29 PM

Oh. If anyone wanted to build that, I used 22uF for the real output filter. The little cap was just so the simulation would settle fast enough on my free computer.

Elvee · 13th September 2010, 08:15 AM

Here is another DVM adapter for inductance. It's slightly more complex, but has a resolution of 10nH, can have up to 6 ranges, and has a decent rejection of minor parameters (mainly series resistance):
[En cours]Inductancemètre: la version jouet - Forum Projets électroniques

pjp · 14th September 2010, 02:58 PM

Hi Elvee, if there are no copyright issues, could you please attach the pdf from your link here ?

That forum requires registration to view the pdf, and the registration page is in french (and I don't know french).

10th September 2010, 10:26 PM	#11
Radioman62 diyAudio Member Join Date: Mar 2005 Location: Near Gothenburg, the westcoast of Sweden	Elvee You refer to .. as it seems interresting links but the languish problem persist. I will try with google translate and let you know if I went happy about the information je suis a room avec douche silvoplait Have fun! __________________ Cheers// Ove

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11th September 2010, 06:58 AM	#12
Elvee diyAudio Member Join Date: Sep 2006	Sorry, I have no idea about the identity of your guy at MW. For the projects, the text is in french, but schematics and pictures are universal. Of course, there is always the risk to miss a small detail, just as I did.

11th September 2010, 06:10 PM	#13
zdr diyAudio Member Join Date: Nov 2005 Location: Brussels	I build mine with Lm833 (burnt my only lm358 as there is a blunt error in ps polarity on the web page), and finally made it work, running on single 9V PS with virtual ground. I have ridiculous errors of around 20-50% at 1KHz, for 100ohm range (0.82mH reported as 0.99, 3.9 ohm as 5.6, etc). Some serious issues with app not entering calibration mode, then getting stuck in calibration mode, and so on... Starting to remind me of speaker workshop on which I wasted a good week before I threw it away together with it's jig. I hope I am missing something as usual What do you guys use as PS? Which version you built?

11th September 2010, 06:28 PM	#14
zdr diyAudio Member Join Date: Nov 2005 Location: Brussels	Actually, I swapped back my supposedly dead LM358, and guess what - not only that is not dead, but also measured my 0.82mH coil as 0.8224mH I guess we all better stick with the recipe and use LM358 as specified by author. Digits are also quite calm... Back to more testin'

12th September 2010, 09:51 PM	#16
zdr diyAudio Member Join Date: Nov 2005 Location: Brussels	I just could not make it work properly with my SB Audigy, running on KX Drivers. It was off 4 times just by switching range... But, with built in SoundMax, works like a charm, quite consistent. If I measure 3.3uF with 100 ohm then switch to 1000 ohm with same DUT, it's off by 0.02uF; but, that could be due to measurement resistor tolerance, so I ordered some 0.01% resistors to replace 1% ones. I wonder how much they influence overall accuracy... I cannot compare to any stock meter, but it seems to be quite accurate. Finally a good, working and cheap LCR meter

12th September 2010, 11:29 PM	#18
Andrew Eckhardt diyAudio Member Join Date: Nov 2005 Location: PA	Oh. If anyone wanted to build that, I used 22uF for the real output filter. The little cap was just so the simulation would settle fast enough on my free computer.

13th September 2010, 08:15 AM	#19
Elvee diyAudio Member Join Date: Sep 2006	Here is another DVM adapter for inductance. It's slightly more complex, but has a resolution of 10nH, can have up to 6 ranges, and has a decent rejection of minor parameters (mainly series resistance): [En cours]Inductancemètre: la version jouet - Forum Projets électroniques

14th September 2010, 02:58 PM	#20
pjp diyAudio Member Join Date: Nov 2006 Location: under the rainclouds	Hi Elvee, if there are no copyright issues, could you please attach the pdf from your link here ? That forum requires registration to view the pdf, and the registration page is in french (and I don't know french).