$20 LCR ESR Transistor checker project

[13hm13]

The problem I have with the cheap $20 checkers is REPEATABILITY and RELIABILITY of results.
For example, an electro cap may read a certain value (or esr) on first check .... remove it ... short it to discharge ... repeat the check ... and wham ... readings are anywhere from either slightly different to very different.

How do I "upgrade" the same $20 checker for better (more RELIABLE and REPEATABLE) performance?

I have not tried out any of the pricer (name brand) meters, like BK or Fluke.

I do own two Fluke DMMs including the 87. And, frankly, in my experience, the 87 is also not all that RELIABLE and REPEATABLE, sometimes requiring a power cycle to clear its memory or software lockup.

I haven't gone thru this thread (much less all of EEVblog) for some solution to my queries below, so please throw some links as necessary.

[Peeps]

I'm running the MK-328 tester (atmega328p) and just upgraded to the 1.40m firmware. It seems to be working fine for most things, except it won't properly detect these TRIACS I have. They're model BTA16-800BW (datasheet), and it shows them as being a ~60ohm resistor between the Gate and M1 regardless of how the leads are connected.

The TRIACS are definitely good as they're brand new from digikey, and read the same as the old ones I was going to replace them with.

[13hm13]

What are important differences between MK-328 and LCR-TC1 testers?
They are similar price on ebay or Ali.

[madires]

I'm running the MK-328 tester (atmega328p) and just upgraded to the 1.40m firmware. It seems to be working fine for most things, except it won't properly detect these TRIACS I have. They're model BTA16-800BW (datasheet), and it shows them as being a ~60ohm resistor between the Gate and M1 regardless of how the leads are connected.

Please see the README, section Displaying Results / Additional Hints / TRIACs. That TRIAC needs more current than the tester is able to provide.

[madires]

What are important differences between MK-328 and LCR-TC1 testers?
They are similar price on ebay or Ali.

The TC-1 has a color display, IR receiver module and boost converter for the Zener check (up to about 35V). And it comes with an ATmega324 or 644 plus an annoying control MCU (requires reprogramming or replacement with a simple two-transistor circuit).

[madires]

The problem I have with the cheap $20 checkers is REPEATABILITY and RELIABILITY of results.
For example, an electro cap may read a certain value (or esr) on first check .... remove it ... short it to discharge ... repeat the check ... and wham ... readings are anywhere from either slightly different to very different.

It should be clear that the Transistortester isn't a precision instrument, but it can be quite accurate. Most problems are caused by a cheap power supply circuitry.

BTW, you don't need to remove the cap for discharging between probing cycles. Just keep it inserted. But make sure it's discharged before inserting.

How do I "upgrade" the same $20 checker for better (more RELIABLE and REPEATABLE) performance?

MCP1702/MCP1703 and remove the TL431. Don't forget to run the self-adjustment.

[13hm13]

The problem I have with the cheap $20 checkers is REPEATABILITY and RELIABILITY of results.
For example, an electro cap may read a certain value (or esr) on first check .... remove it ... short it to discharge ... repeat the check ... and wham ... readings are anywhere from either slightly different to very different.

It should be clear that the Transistortester isn't a precision instrument, but it can be quite accurate. Most problems are caused by a cheap power supply circuitry.

BTW, you don't need to remove the cap for discharging between probing cycles. Just keep it inserted. But make sure it's discharged before inserting.

How do I "upgrade" the same $20 checker for better (more RELIABLE and REPEATABLE) performance?

MCP1702/MCP1703 and remove the TL431. Don't forget to run the self-adjustment.

You mean replace the TL431 with MCP1702/03?
About the PSU ... I assume 9v (which is the default for my tester, via the battery jack) is okay??? If not, please make specific suggestions. For example, a 9v ac/dc wall-wart adapter --- but with extra filtration and/or better regulation.

Let's say that our goal is create a $30 meter that can match, say, the BK 879B --- Is this possible?



https://www.bkprecision.com/products/component-testers/879B-40000-count-dual-display-handheld-lcr-meter-with-esr.html

[13hm13]

I just checked what I have .... it's an "MTester" ...



The regulator is 78L05. Not sure how to improve on this topology?

[madires]

You mean replace the TL431 with MCP1702/03?

Nope, replace the 5V regulator with an MCP1702/03 and remove the TL431.

About the PSU ... I assume 9v (which is the default for my tester, via the battery jack) is okay??? If not, please make specific suggestions. For example, a 9v ac/dc wall-wart adapter --- but with extra filtration and/or better regulation.

9V battery is fine.

Let's say that our goal is create a $30 meter that can match, say, the BK 879B --- Is this possible?

No, the Transistortester isn't an LCR meter which typically uses an AC test signal. Completely different measurement method.

[madires]

I just checked what I have .... it's an "MTester" ...

... or commonly known as T4 clone.

[madires]

Not really. It only mitigates the problem for caps up to about 2200µF.

Update:
For some unknown reason the residual voltage of a large value cap is higher on the Hiland M644 and some other clones. The algorithm of the ESR measurement is able to compensate some residual voltage, e.g. caused by dielectric absorption, but in this case the voltage is too high. Despite the cap being discharged before the ESR measurement the residual voltage stays quite high. I've added a dedicated function to discharge caps which works fine so far (tested up to 10mF).

[13hm13]

No, the Transistortester isn't an LCR meter which typically uses an AC test signal. Completely different measurement method.

Are you sure? I'm referring to tester shown in my photos (MTester). It can test L, C, R, ESR, as well as semiconductors (trans, diodes). It does test using high-freq AC sweep.

[edavid]

No, the Transistortester isn't an LCR meter which typically uses an AC test signal. Completely different measurement method.

Are you sure?

I'm referring to tester shown in my photos (MTester). It can test L, C, R, ESR, as well as semiconductors (trans, diodes).

That doesn't make it an LCR meter.

It does test using high-freq AC sweep.

No, it doesn't.  Consult the source code and documentation.

However... I think it's clearer to say that an LCR meter like the B+K 879B uses a vector (phase sensitive) measurement technique.  The Transistortester only makes scalar measurements.

[13hm13]

That doesn't make it an LCR meter.

Your comments are CONFUSING .... to say the least!!
Please note the title of this thread. See the "LCR" ?
I would buy it if you said that the BK unit is a better, more reliable implementation of supporting metrology. But note the original goal of the $20 LCR ESR Transistor checker project was to bring formally expensive-to-do measurements (e.g. BK or Peak tools, and all their functionality ) down to a bare-bones price.

[CatalinaWOW]

That doesn't make it an LCR meter.

Your comments are CONFUSING .... to say the least!!
Please note the title of this thread. See the "LCR" ?
I would buy it if you said that the BK unit is a better, more reliable implementation of supporting metrology. But note the original goal of the $20 LCR ESR Transistor checker project was to bring formally expensive-to-do measurements (e.g. BK or Peak tools, and all their functionality ) down to a bare-bones price.

We are now dancing around the definition of functionality.  The $20 meter measures L, C and R so by some definition it is an LCR meter.  And the accuracy it achieves is more than sufficient for a great many purposes.  If it is not sufficient for your purposes you are doing something which requires more than basic knowledge, and you should know what you need and in what ways this meter doesn't do it.  You should also know if the fancier LCR meters that cost hundreds or thousands of dollars are adequate to your purpose.  There are times when they are not.

A 2.5 digit DMM and a 8 digit DMM are both DMMs.  The 2.5 digit unit is actually adequate for what I would guess is the high nineties percent of all readings.  But it won't do what the 8 digit unit will do, and should never be confused with it.  If you look at the single specification of price there should be little chance of confusion.

[indman]

Your comments are CONFUSING .... to say the least!!

This absolutely does not bother those people who constantly follow this topic and have carefully studied all the documentation, kindly and gratuitously provided by the authors of the project. Many thanks to them for this great work! 
First of all, this project is Transistor checker project ! LCR measurement is bonus functions that the authors were able to implement based on the capabilities and limitations of the simplified circuitry of this device. They do not claim metrological accuracy! You should always remember this and do not try to put specialized professional LCR meters and this project on the same scales.

[13hm13]

Your comments are CONFUSING .... to say the least!!

This absolutely does not bother those people who constantly follow this topic and have carefully studied all the documentation, kindly and gratuitously provided by the authors of the project. Many thanks to them for this great work! 
[      ]

First of all, this project is Transistor checker project ! LCR measurement is bonus functions that the authors were able to implement based on the capabilities and limitations of the simplified circuitry of this device. They do not claim metrological accuracy! You should always remember this and do not try to put specialized professional LCR meters and this project on the same scales.

But I am putting " this project on the same scales." And, thus, your reply is a complete FAIL!!! 

We are now dancing around the definition of functionality.  The $20 meter measures L, C and R so by some definition it is an LCR meter. 

Oh, so now (despite the thread title) it's "by some definition it is an LCR meter.  "   . Y'all just stick up fer one another, mincing words,  without rhyme or reason. Geeeeeeeeeeeeeeeeeeeeeeeeezusssssssssssssss!

Okay, so now let a low-post-count "Regular Contributor" like me throw some advice.
You might want to reply back with some rhyme or reason. For example, BKP created a product video detailing how LCR meter works for various components.

https://youtu.be/zZiVvgUiRdc

(Watch this short video, and pay attention class!!!! This is how to reply. HINT: Y'all might wanna say, e.g., how the MTester selects and spits out test signals to "sweep" for component type, etc.). Now some/all this info may already be in this thread. In my orig. query post, which OBVIOUSLY most y'all didn't read,  I specifically asked for links. But y'all apparently neglected that in favor of throwing out spitfire, diatribes and criticism. GEEEEEEEEEEEEEEEEEEEEEZUSS   

Well here's lookin' back at ya kids ..... and a one more thanggggggggggggggggggggggg...

[madires]

Please read https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/ttester-1.13k.pdf!

I don't expect anyone to read this whole thread, but the common questions about which tester to buy, how to pimp your tester or where to find the documentation are answered usually in the last ten pages. There's also a nice text field at the top right for searching this topic.

So please let's keep this discussion civilized!

[madires]

No, the Transistortester isn't an LCR meter which typically uses an AC test signal. Completely different measurement method.

Are you sure? I'm referring to tester shown in my photos (MTester). It can test L, C, R, ESR, as well as semiconductors (trans, diodes).

And with a current firmware it will do many things more. But as one of the two developers of this OSHW project I'm pretty sure.

[indman]

But I am putting " this project on the same scales." And, thus, your reply is a complete FAIL!!! 
Are you sure? I'm referring to tester shown in my photos (MTester). It can test L, C, R, ESR, as well as semiconductors (trans, diodes).

This manner of communication reminds me very much of one "gentleman" Stan21, doesn't it?

[timelessbeing]

This manner of communication reminds me very much of one "gentleman" Stan21, doesn't it?

Exactly what I was thinking. I marvel at how skilled some people are at making complete jack-asses of themselves. It requires a stupendous lack of self reflection.

[13hm13]

This manner of communication reminds me very much of one "gentleman" Stan21, doesn't it?

Exactly what I was thinking. I marvel at how skilled some people are at making complete jack-asses of themselves. It requires a stupendous lack of self reflection.

The WHACKY responses to y'alls lazy AF replies are exactly what you DESERVE. I openly admitted I don't know exactly how the MTester works. And asked some legitimate questions....e.g., a brief overview of how the MTester works (compared to a formal LCR meter, like BK)
 But what I got instead was the typical dismissals or smarty-pants lazy AF responses -- all typical of sciency forums.
KEEP IN MIND A COUPLE O' 'PORTANT FACTS-O-LIFE:
Y'all have spent over 260 pages on a friggin' $7 tester 
Some of you claimed the MTester is NOT an LCR meter (despite the title of this thread, one of you actually said this )    

So ... I'm still waiting for a few words -- or a hyperlink -- on how the "$20 LCR ESR Transistor checker" works. That's not that big of an ask, exp. given the size and messiness of this thread.

[Simon]

This manner of communication reminds me very much of one "gentleman" Stan21, doesn't it?

Exactly what I was thinking. I marvel at how skilled some people are at making complete jack-asses of themselves. It requires a stupendous lack of self reflection.

The WHACKY responses to y'alls lazy AF replies are exactly what you DESERVE. I openly admitted I don't know exactly how the MTester works. And asked some legitimate questions....e.g., a brief overview of how the MTester works (compared to a formal LCR meter, like BK)
 But what I got instead was the typical dismissals or smarty-pants lazy AF responses -- all typical of sciency forums.
KEEP IN MIND A COUPLE O' 'PORTANT FACTS-O-LIFE:
Y'all have spent over 260 pages on a friggin' $7 tester 
Some of you claimed the MTester is NOT an LCR meter (despite the title of this thread, one of you actually said this )    

So ... I'm still waiting for a few words -- or a hyperlink -- on how the "$20 LCR ESR Transistor checker" works. That's not that big of an ask, exp. given the size and messiness of this thread.

Have you finished or do you need finishing? I don't care what others have said your posts are rather over the top and if anything anyone said warranted such rubbish then you report it rather than posting that crap!

[madires]

So ... I'm still waiting for a few words -- or a hyperlink -- on how the "$20 LCR ESR Transistor checker" works. That's not that big of an ask, exp. given the size and messiness of this thread.

Apparently you've missed the linked documentation a few posts earlier. That PDF explains all the details. It helps if you can read.

[timelessbeing]

... if you can read.

Judging from his command of English, not very well