miszt

ATMega based LCRs
« on: January 15, 2016, 05:37:15 AM »
has anyone tried these cheap ATMega based LCRs, I cant find much info on how accurate they actually are?

they are based on an open source project which seems to have quite allot of support, although the ones available to buy online are clones of apparently variable quality


peterc

Re: ATMega based LCRs
« Reply #1 on: January 15, 2016, 08:40:43 AM »
I have 2 and I use them regularly.

At first I was a bit suspicious and used to confirm my readings with a Fluke meter, but now I dont worry.

Mine have a transistor tester in as well which is nice.

Peter
If opportunity doesn't knock, build a door.

miszt

Re: ATMega based LCRs
« Reply #2 on: January 15, 2016, 08:55:08 AM »
mine arrived this morning, and so far i'm pretty impressed, none of the components I've tested came outside of their stated range; and its great being able to stick a transistor in and be told instantly what it is, without having to strain to read the print and then look it up

one thing I wondered about was with capacitors and drift; i'm trying to match ones which are labelled 10% tolerance, and according to the LCR, I've managed to find pairs that are within 0.5% of each other for about 2/3's of the capacitors I was testing, all the rest are in 1% pairs - if the readings are accurate, then i'm very impressed (and happy lol)... i guess i'll find out if I have a wonky stereo field when my PQD2 is finished

(going to test all the pairs again a few times before I accept the readings i think)

miszt

Re: ATMega based LCRs
« Reply #3 on: January 16, 2016, 05:50:13 AM »
spent the morning double checking all the capacitor pairs, got almost identical readings to yesterday; the only noticeable difference comes when testing a capacitor twice, without shorting it before testing the second time - and then the difference has so far still only been 0.1%-0.2%

either these things are unbelievably accurate, or they are reliably inaccurate lol either way the best £10 I've spent in a long while :)

gyraf

Re: ATMega based LCRs
« Reply #4 on: January 16, 2016, 06:30:26 AM »
Agreed. I built one of these last week - http://www.banggood.com/DIY-Meter-Tester-Kit-For-Capacitance-ESR-Inductance-Resistor-NPN-PNP-p-929603.html - and I'm amazed how usable it is for the price...

The only half-weak spot is inductor measurement (this is stated in the manual) which is a bit off, but still VERY usable for relative measures.

Jakob E.
..note to self: don't let Harman run your company..

miszt

Re: ATMega based LCRs
« Reply #5 on: January 16, 2016, 08:27:57 AM »
Agreed. I built one of these last week - http://www.banggood.com/DIY-Meter-Tester-Kit-For-Capacitance-ESR-Inductance-Resistor-NPN-PNP-p-929603.html - and I'm amazed how usable it is for the price...

The only half-weak spot is inductor measurement (this is stated in the manual) which is a bit off, but still VERY usable for relative measures.

Jakob E.

had a quick read through, the only ref I can find to inaccurate inductance readings are with <2.1K resistors; any idea what the accuracy is for inductor measurements? cant find anything online yet

miszt

Re: ATMega based LCRs
« Reply #6 on: January 27, 2016, 04:21:28 AM »
Spent the week matching resistors, and discovered my unit over calculates values consistently; I only realized when I checked some 0.1% 9.09K resistors, they read as 9.13K, all of them

gyraf

Re: ATMega based LCRs
« Reply #7 on: January 27, 2016, 07:51:37 AM »
..note to self: don't let Harman run your company..

miszt

Re: ATMega based LCRs
« Reply #8 on: January 27, 2016, 10:59:34 AM »
I've got the ready made Chinese one, I've read that they can be calibrated but not reliably...i might get the official GPL kit and build it at some point

gyraf

Re: ATMega based LCRs
« Reply #9 on: January 28, 2016, 03:51:09 AM »
On my very-cheap kit (from Banggood, above) I get a reading of 10.03 KOhm for a resistor that measures 9.963 KOhm on my calibrated Fluke45.

That's a deviation of 0.6%

which is quite good considering the kit's $11.5 price tag...

Jakob E.
..note to self: don't let Harman run your company..


miszt

Re: ATMega based LCRs
« Reply #10 on: January 28, 2016, 10:23:45 AM »
It seems that the measurements are at least consistent, ie I don't get a different reading for the same resistor at different times

Re: ATMega based LCRs
« Reply #11 on: March 05, 2016, 07:55:42 PM »
Wow. Not bad for under $15. I can deal with +-0.6% for on-the-fly measurements.

On my very-cheap kit (from Banggood, above) I get a reading of 10.03 KOhm for a resistor that measures 9.963 KOhm on my calibrated Fluke45.

That's a deviation of 0.6%

which is quite good considering the kit's $11.5 price tag...

Jakob E.
Sincerely,    
Chris Juried 
Audio Engineering Society (AES) Member
http://www.JuriedEngineering.com
http://www.TubeEquipment.com
http://www.HistoryOfRecording.com

Whoops

Re: ATMega based LCRs
« Reply #12 on: May 04, 2017, 09:43:59 PM »
I got this one,
Portable MK328 LCR ESR Tester transistor inductance capacitance resistance meter

http://www.ebay.co.uk/itm/Portable-MK328-LCR-ESR-Tester-transistor-inductance-capacitance-resistance-meter-/171927184554?hash=item2807a8a4aa:g:MdoAAOSwk0pVgETb


Let me tell you I'm really impressed, for the price it's the best measuring tool you can have.
I really recommend this to everyone.

Imagine how much electronic engineers would pay for a unit with these capabilities in the 70s....

ungifted

Re: ATMega based LCRs
« Reply #13 on: May 05, 2017, 04:50:21 PM »
I've got various types - L3-L4, M328 (latest, with generator and encoder). Really good tester for transistor testing etc, but must have one of the latest firmware - 1.11k-1.12k
https://www.mikrocontroller.net/articles/AVR-Transistortester
Purchased it for testing germanium transistors: i will compare it with DCA55/75, rg keen and small bear jigs.
http://diy-tubes.com - parts for guitar/studio gear

Whoops

Re: ATMega based LCRs
« Reply #14 on: May 05, 2017, 08:41:13 PM »
I've got various types - L3-L4, M328 (latest, with generator and encoder). Really good tester for transistor testing etc, but must have one of the latest firmware - 1.11k-1.12k

I have to check with firmware came with my unit.

In case I have an old firmware is it possible to update it?

thanks

ungifted

Re: ATMega based LCRs
« Reply #15 on: May 06, 2017, 06:01:50 PM »
Yes, it's possible to upgrade firmware (usb AVR programmer needed). Here is the link
https://yadi.sk/d/yW8xa5NJgUo5z/Mk-328/Firmware

There is a lot of info over www, incl youtube movies describing how to upgrade your transistor tester.
http://diy-tubes.com - parts for guitar/studio gear

Whoops

Re: ATMega based LCRs
« Reply #16 on: May 07, 2017, 10:04:09 PM »
Thanks, going to check that

squarewave

Re: ATMega based LCRs
« Reply #17 on: May 18, 2017, 02:00:12 PM »
Purchased it for testing germanium transistors: i will compare it with DCA55/75, rg keen and small bear jigs.
Can these really measure Germanium transistors / diodes accurately? One of these would be great if they really properly report leakage, gain and diode drop of a Germanium transistor.

ungifted

Re: ATMega based LCRs
« Reply #18 on: May 18, 2017, 02:39:25 PM »
Please take a look at my post at diydtompboxes, I've compared all I've got:
http://www.diystompboxes.com/smfforum/index.php?topic=117061.msg1092755#msg1092755
http://diy-tubes.com - parts for guitar/studio gear

cyrano

Re: ATMega based LCRs
« Reply #19 on: May 18, 2017, 05:03:12 PM »
Very interesting. Not only the meters, but also the Russian germanium transistors. Thanks!
Why is it people love to believe and hate to know?