$20 LCR ESR Transistor checker project

[madires]

Changes for v1.31m:
- New tool: IR RC transmitter.
- Added support for dedicated signal output via OC1B, when OC1B isn't used for test pin #2's probe resistor.
- Changed battery monitoring settings to support also other power options.
- Driver for SSD1306 based graphic OLED modules.
- Color support for item selection (menues and tools).
- Driver for ILI9163 based graphic color LCD modules.
- Fixed tiny issue in squarewave signal generator.
- Added support for 180° rotated output to PCD8544 LCD driver.
- Fixed edit error in Servo_Check().

The IR RC supports following protocols at the moment:
- NEC standard & extended
- Samsung/Toshiba (32 bits)
- Sony SIRC 12, 15 and 20 bits

More protocols to come...

[bitseeker]

Changes for v1.31m:
- New tool: IR RC transmitter.

Ah, so you can change the channel while checking ESR on old gear for repair.

[dazz]

n00b alert!

Hi everyone, let me start by saying thanks to Dave and all the contributors to this particular project. Vielen danke!
So I'm a guitar player, a pretty bad one at that, LOL but anyway. I came across Antigua's wonderful work here http://guitarnuts2.proboards.com/thread/7723/measuring-electrical-properties-guitar-pickups where he explains the electronic properties of guitar pickups and how to test them. Most of that goes well over my head, but apparently being able to measure guitar pickups' inductance (and capacitance?) provides some useful information about their theoretical frequency response.

So we've ordered these TCR-T4's and wondering if they can be used or the firmware can be modified to accomplish our goal? I'm a software guy and I'm more than willing to get my hands dirty

[Willem52]

Please see message reply #4242

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1365473/#msg1365473

[dazz]

So according to the manual, inductance measurement runs for resistance values under 2K1R if I got that right.
Guitar pickups are typically above 5KR and inductance of several H's (2H, 4H etc..)

Does that mean that this device will not be capable of reading pickup inductance? Here's the one I ordered https://www.ebay.es/itm/112527481729

[stj]

why not just play some chords on it and capture it on a pc.
then you can see the frequencys  in some audio editing software

[dazz]

why not just play some chords on it and capture it on a pc.
then you can see the frequencys  in some audio editing software

My uneducated guess is that would introduce too many factors to make the test meaningful: pickup position, string type and wear, picking technique, saddle material, tonewood... 

[madires]

So according to the manual, inductance measurement runs for resistance values under 2K1R if I got that right.
Guitar pickups are typically above 5KR and inductance of several H's (2H, 4H etc..)

Does that mean that this device will not be capable of reading pickup inductance? Here's the one I ordered https://www.ebay.es/itm/112527481729

Yep, it won't try to measure the inductance when the resistance is larger then 2k. For those kind of measurements I'd suggest to get a proper LCR meter.

[dazz]

So according to the manual, inductance measurement runs for resistance values under 2K1R if I got that right.
Guitar pickups are typically above 5KR and inductance of several H's (2H, 4H etc..)

Does that mean that this device will not be capable of reading pickup inductance? Here's the one I ordered https://www.ebay.es/itm/112527481729

Yep, it won't try to measure the inductance when the resistance is larger then 2k. For those kind of measurements I'd suggest to get a proper LCR meter.

Thank you madires.

How about this "sampling ADC" method described in section 3.10 of the manual?

With the samplingADC method a resonant frequency
of coils can be detected with greater inductance values. If this effect is noticeable, the frequency and
the quality factor Q of the coil is shown additionally in line 3.
The method of resonant frequency measurement can also be used for the determination of the
inductance value, if a sufficient big capacitor mith know capacity value is connected parallel to a little
inductance (<2mH). With a parallel connected capacitor the normal measurement of inductance
can no more operate well. If the resonant frequency let assume a parallel connected capacitor, the
inductance of the normal measurement is not shown and the resistance value is shown in line 1. For
this resonant circuit the quality factor Q is also computed and shown behind the frequency value in
line 3. You can identify this type of measurement with the inductance value at the first position of
line 2, followed by the text ” if ” and the value of the assumed parallel capacity. The value of this
3 10 ? 30nF (L)).
parallel capacitor can currently only be set with the calibration function (1
For displays with only two lines, the content for the third line is shown time-delayed in line 2.

[madires]

The k-firmware's sampling ADC might work. I haven't tried it with large inductance values yet.

[dazz]

The k-firmware's sampling ADC might work. I haven't tried it with large inductance values yet.

Great! I'll need to flash this .eep & .hex files, right?

ETA: this programmer would work? https://www.ebay.es/itm/LC-01-51-AVR-Programmer-ISP-USBASP-Downloader-USBISP-Download-Line/152706097159?hash=item238dfe2007:g:W7MAAOSwVfxZvWuz

[madires]

Yes & yes.

[dazz]

Does anybody know what firmware these T4's come with?

[madires]

AFAIK, they run a modified k-firmware.

[all_repair]

It's really a quite beautiful case and PCB!
It's currently running firmware 1.11k and it was not locked so was possible to save it unlike most others I've seen.

I had an idea to also fit a ATtiny44 SMD PCB inside for easy programming.
It fits great but I realize a problem: it interferes with the sense resistors and thus can't be in circuit while measuring.
So now I'm thinking to find a 5v relay to drive via the USB port too, so it switches the 4 signal wires over. (MOSI, MISO, SCK & Reset)
Currently considering Panasonic S4-5V. Will see how that goes, or anyone have some better solution?

By any chance you have captured the firmware?  First time I blew one of these.  The socket clips make capacitor testing so easy.  I picked up a big capacitor from my storage to try to confirm something, and blew my set after I had it for a few days.   Too easy to use, a bit too easy to blow 😉

[Per Hansson]

Yes of course, here you go.
Just one caveat to be aware of: it contains the calibration data from my meter.
So you should make a new calibration even though you will have no message telling you it's not calibrated....
And the fuses where set according to the picture included.

[cvanc]

Hi all-

I want to buy an assembled, ready to use tester, hopefully with a color screen.  Ideally I could find a source here in the U.S.  Is there a model or models that are currently considered "the good ones"?

Also, can anyone explain the difference between this 'B1' and 'B2' version?  (and... is this a decent meter in either version?)

https://www.ebay.com/itm/B1-Color-1-8-TFT-ESR-Meter-Transistor-Resistor-Diode-Triode-Capacitor-Tester/322869859401?hash=item4b2c8b1449:g:jkEAAOSwU1FaAlx0

https://www.ebay.com/itm/B2-Color-1-8-TFT-ESR-Transistor-Resistor-Diode-Capacitor-Mosfet-Tester/232448188853?hash=item361efde1b5:g:~RIAAOSweNxZkd8h

Thank you.

[rhb]

I've not read this thread much.  As Dave noted, tl;dr.  I *am* quite interested though.

I just sent an email proposing to EEVblog that a wiki be set up where the generally useful content of threads like this can be more easily accessed.  If you think this would be a good idea, please comment here:

https://www.eevblog.com/forum/suggestions/equipment-wikis/

[mebel]

Hello everyone

I would like to replace TL431A to TL431B to get better accuracy measurement in  "AY-AT" but I can not find TL431B. I found TL431ZCLS IK-SEMICON. Will it be good? Do I have to also  replace something else to get it worked?
Here is the reference.

https://www.maritex.com.pl/product/attachment/35707/TL431Z_03.pdf

[madires]

I want to buy an assembled, ready to use tester, hopefully with a color screen.  Ideally I could find a source here in the U.S.  Is there a model or models that are currently considered "the good ones"?

Also, can anyone explain the difference between this 'B1' and 'B2' version?  (and... is this a decent meter in either version?)

I'd go for an assembled AY-AT. The tester you've mentioned is a simple one running a modified firmware. The only difference between the the two models seems to be the color of the case.

[madires]

I would like to replace TL431A to TL431B to get better accuracy measurement in  "AY-AT" but I can not find TL431B. I found TL431ZCLS IK-SEMICON. Will it be good? Do I have to also  replace something else to get it worked?

It's a 0.5% type. You just need to replace the TL431. That's all to be done.

[madires]

I've not read this thread much.  As Dave noted, tl;dr.  I *am* quite interested though.

I just sent an email proposing to EEVblog that a wiki be set up where the generally useful content of threads like this can be more easily accessed.  If you think this would be a good idea, please comment here:

https://www.eevblog.com/forum/suggestions/equipment-wikis/

Jake (jakeisprobably) is working on something similar already, just for the Transistor Tester.

[stj]

Hello everyone

I would like to replace TL431A to TL431B to get better accuracy measurement in  "AY-AT" but I can not find TL431B. I found TL431ZCLS IK-SEMICON. Will it be good? Do I have to also  replace something else to get it worked?
Here is the reference.

https://www.maritex.com.pl/product/attachment/35707/TL431Z_03.pdf

forget that, use an LM4040

[Seabird]

I hope that I am not hijacking this thread (apologies in advance if I am)!  I have just purchased a LC-T3-H which has a very similar board layout to this schematic published earlier in this thread.  Somehow, I inadvertently got into the contrast setting and stupidly kept pressing the button in the hopes it would roll over and I would regain a readable display - Duh!  With the blank screen I now have no way of knowing what I am doing.  My questions are:  is there a 'factory reset' sequence I could use?  Are there a series of key strokes that somebody could provide to decrease the contrast setting (knowing that I would be doing this blind)?  Another thought I had was to physically wire the contrast pin of the LCD to a potentiometer to manual adjust while I get things back to normal but I am not sure which is the correct pin on the LCD?  Of course, any other suggestions that would help me get out of this dilemma will be appreciated.

[indman]

Seabird
In this firmware the contrast range is regulated programmatically. It is necessary for you it is long to press the Test button, then short clicking to change contrast range. Only 10 options of level of contrast range.