$20 LCR ESR Transistor checker project

[mauroh]

Hi Pierre,
   I had few minutes waiting for a meeting and took the opportunity to play a bit with your schematic, hope you don't mind It was just for fun.
Now the encoder should be fine and I moved few dots in the "proper" position.

Generally speaking I think the issue with the dots is related on how Eagle works.
You should avoid start a junction or a 90degree corner on a component pin.
If you do that, Eagle attach the junction to the component pin and if you move the component you drag the dot junction with it.
I don't like to draw lines or components underneath other components and I moved some wires to avoid it.
I prefer to use the GND simbol and power pin simbol instead of drawing all the wires for the power all around the schematic, but I didn't change that.

Please let me know if was this was helpful.
Enjoy your drawing 

Mauro

PS: Why use Eagle? I got used to it and I'm struggling to move to Kikad. For small board it is free, so sometimes for me is just faster to do it in Eagle.

[madires]

  If I can figure out the programming side of this device (total ISP noob), I want to add the zener threshold tester, but I plan to use a MC34063 if I go that route.

I'd recommend to add a second 5V LDO with proper bypass caps for the boost converter. One of my testers got a MC34063 based boost converter but modules like the MEA 1W series from muRata are more convenient and efficient

   ...And if everything goes really well I'd like to look into adding a INA106 differential amplifier with a laser trimmed gain of 10. I was planning to build the milliohm meter from the Scullcom Hobby Electronics YouTube channel, but I think the diff amp might be more useful when integrated into this project. I would probably need help understanding the programming aspects involved to make this happen, but I think this little mod could be interesting.

Me too. Would be a nice hardware option.

   The last thing I've been looking into is why "discharged capacitors" are mentioned, but only 'before the device is powered on.' I assume this is due to the TVS IC's need for power. If that's the case, why not simply add a 2 pole normally closed relay to short all 3 test leads with a short on delay circuit powered from the collector of the PNP transistor? Seems like that would solve the problem of mega-burns, but I've not done my research in this area yet.

The SRV05-4 is "passive" and doesn't need any supply voltage. And there's aleady a discharge/protection relay add-on. Have you seen Karl-Heinz' excellent documentation ( https://github.com/svn2github/transistortester/blob/master/Doku/trunk/pdftex/english/ttester.pdf ) yet?

[mauroh]

I'd recommend to add a second 5V LDO

I preferred a 5V micro switching module.
It can deliver much more current and can be used for:
  - servo test (with the m-firmware)
  - bluetooth module (enabling the serial output on the k-firmware)
  - Zener test (as the input for the boost converter)

I added also a switch to save battery power if this secondary voltage is not in use.
I would add the 3 pin standard header for the servo test and a connector for the serial output (PC3 on the k-firmware).

Mauro

[jorgemiguel4]

Yes, I have tried with two similar ones with similar results. The last one read 6.36mH and 148 Ohm while in my multimeter it reads 0.63 Ohm.  Don't know if it matters but both inductors are common mode chokes.

That's strange! I've checked a 2.7mH and 22mH common mode choke with the m-firmware an an older k-firmware. The measured values are reasonable.

It may be a problem with this specific model, I found a video review on youtube that shows a inductor test and it seems to have the same issue. See the attachment

 

[perieanuo]

To bianchifan:
HI,
just tried kicad.it's the biggest piece of s..eet I ever seen.
I did recomended for someone eagle because it's free and easy to use.dont't need to pass 1 hour to play library parts or digging footprints.
me,i use altium and of course i'll never recommend it,that's other's people job.
and I'm feel free to use everything I consider apropriate to play with this project,even it's payed,windows etcaetera.
btw I was rectified my errors on my first schematic,still one remaining and looking to start a brand new implementation.

you on the other side can use whatever you like without having others on your back.hope you appreciate,it's called FREEDOM of choice,even that means to be stupid to choose payed sw who works by the way almost everytime.

[perieanuo]

Hi Pierre,
   I had few minutes waiting for a meeting and took the opportunity to play a bit with your schematic, hope you don't mind It was just for fun.
Now the encoder should be fine and I moved few dots in the "proper" position.

Generally speaking I think the issue with the dots is related on how Eagle works.
You should avoid start a junction or a 90degree corner on a component pin.
If you do that, Eagle attach the junction to the component pin and if you move the component you drag the dot junction with it.
I don't like to draw lines or components underneath other components and I moved some wires to avoid it.
I prefer to use the GND simbol and power pin simbol instead of drawing all the wires for the power all around the schematic, but I didn't change that.

Please let me know if was this was helpful.
Enjoy your drawing 

Mauro

PS: Why use Eagle? I got used to it and I'm struggling to move to Kikad. For small board it is free, so sometimes for me is just faster to do it in Eagle.

Thanks, in fact I was modified my first schematic before that, I left only one little error I was away. I'll move to smd schematics for a complete 328 with my 7735 display.
Tried Kicad , I'll stick to altium.
Best regards

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk

[Gandalf_Sr]

Tried Kicad , I'll stick to altium.

Altium is too expensive and, IMHO, just a pain to work with, I've also found it to crash frequently and, although it's been years since I used it, current users tell me it still crashes. 

I've been using Diptrace for years now and it's really nice; there's a trial version that works for 30 days and then I think it pin-limits and the unlimited version is currently $1,195 and worth every penny.

[jakeisprobably]

Article AVR Transistortester on mikrocontroller.net

   I've read through the English part of that page a couple of times, thanks.
   I am astonished at the history of this project and how different clones have evolved along with the software and fork versions. This was my basis for saying "this needs a wiki." The project is wonderful in it's current configuration/context but the details and evolution of the project deserve their own acknowledgement, in my opinion. A lot of work went into this project to get to it's current iteration. I believe this work should be noticed by everyone not just the few people that have been here all along or the few that read this entire thread history (just a small part of the total project). Also the casual hobbyist or newly interested young kid that grabs an old device off the shelf should be able to understand where their device falls into the mix and what it's capable of. I imagine someone that has an old clone from 2013-2014 has a hard time figuring out what they have and what it is/is not capable of. This thread has lots of older versions I've never seen before.

The SRV05-4 is "passive" and doesn't need any supply voltage.

When a DUT capacitor with a charge is connected, and the test points are connected to a SRV05-4 what exactly causes the failure? Is it simply the potential across the test pins without the completed Vcc to GND loop? I'm mostly confused because of how KH words the warning on the pdf:

... The Tester may be damaged before you have switched it on. There is only a little protection at the ATmega ports.

   Does the same damage occur regardless of whether the device is on or off?

...there's aleady a discharge/protection relay add-on.

  I read somewhere recently (sorry haven't found the ref), there is a problem, as the circuit is documented. The current draw of the transistor/relay combined with the gain of any BJT transistor pulled too much current. They had mentioned the problem was due to the relay connection at the Vref point. Maybe that person was wrong, I don't know, but the maths looked right to my amateur understanding.

Have you seen Karl-Heinz' excellent documentation yet?

  Yes, thanks, I've read through everything but the programming section of version 1.13K. I can't promise that I remember every detail but I have read it.

I'd recommend to add a second 5V LDO

I preferred a 5V micro switching module.
It can deliver much more current and can be used for:
  - servo test (with the m-firmware)
  - bluetooth module (enabling the serial output on the k-firmware)
  - Zener test (as the input for the boost converter)
I added also a switch to save battery power if this secondary voltage is not in use.
I would add the 3 pin standard header for the servo test and a connector for the serial output (PC3 on the k-firmware).
Mauro

*sees Bluetooth serial connection//looks though official pdf document again//head explodes*
  You should show that little Bluetooth module mod on your YouTube channel. I'd like to see more about that.

Why would you run 2 linear regulators? Are you guys implying the use of the DC converter to power the transistor tester itself, or am I misunderstanding something else?

When it comes to what I'm doing with the schematic, my goal is to seamlessly integrate this clone version with the current pdf documentation. Ideally I would like to create a final schematic that mirrors figure 2.1 on page 10 of the pdf documentation exactly. I want to fade an image from the KH-original to my clone version seamlessly. This will allow anyone that reads section 2.1 and several other sections, to seamlessly connect what they read to the clone schematic without the need to translate or figure out the differences on their own.
  Every part number will need to match the clone, and every location should should match the schematic while clearly showing the additional parts of the clone's circuit and all designators.

Sorry I have so many questions, hopefully that doesn't offend anyone.

  Thanks for all the help and support,
 -Jake.

[madires]

The SRV05-4 is "passive" and doesn't need any supply voltage.

When a DUT capacitor with a charge is connected, and the test points are connected to a SRV05-4 what exactly causes the failure? Is it simply the potential across the test pins without the completed Vcc to GND loop? I'm mostly confused because of how KH words the warning on the pdf:

... The Tester may be damaged before you have switched it on. There is only a little protection at the ATmega ports.

   Does the same damage occur regardless of whether the device is on or off?

The SRV05-4 is basically a TVS with some additional diodes to hide the TVS' high capacitance from the input/signal lines. There's also a more beefier TVS in parallel in the tester's circuit. Since we can't add series resistors for the analog inputs of the MCU, which would be done usually to limit the current (which could then be handled by the MCU's internal clamping diodes), this input protection is relatively weak. It might take a slap but not a hit. The benefits are no additional current draw like the protection relay, and being smaller and cheaper than the relay. And yes, it doesn't matter if the tester is on or off.

...there's aleady a discharge/protection relay add-on.

  I read somewhere recently (sorry haven't found the ref), there is a problem, as the circuit is documented. The current draw of the transistor/relay combined with the gain of any BJT transistor pulled too much current. They had mentioned the problem was due to the relay connection at the Vref point. Maybe that person was wrong, I don't know, but the maths looked right to my amateur understanding.

The relay circuit works fine, but the caveat is the additional power consumption by the relay.

Why would you run 2 linear regulators? Are you guys implying the use of the DC converter to power the transistor tester itself, or am I misunderstanding something else?

One LDO to power the MCU and the display, and a second one to power the boost converter for the Zener test. The boost converter draws high current at startup (each time you press the test button) which would impact the MCU. Therefore it's better to decouple the boost converter as much as possible.

[BBBbbb]

@madires
I've been lurking a bit in this topic but I'm lazy to go thorough all the pages, so what I have to ask you might be already answered somewhere in the topic. In that case I apologize.

Is there a model/version of the meter available for purchase that you prefer/endorse? There are numerous LCR meters on ebay, and from what I understand there is no real cooperation between you and any of them.
You're not interested in maybe trying to initiate some kind of cooperation with someone in Chine, like for example Dangerous Prototypes has with Seeed?

Why am I asking this: Well I'm not willing (better say able) to invest a lot of time into choosing and eventually modding (firmware updating not included) a device that I want to keep on a side for just in case , and would readily pay e.g. 30$ (for otherwise 20$ meter) if I see you recommending that one, and if you get a few bucks for it even better. I'm sure I'm not the only one.

[madires]

There's no "official" clone. But if I would buy a tester I'd choose something like the AY-AT kit with a rotary encoder and ST7735 display. I haven't thought about a cooperation with some manufacturer yet. Neither have I received any feedback from a manufacturer so far. If any manufacturer or user likes to support the project, samples of testers (for compatibility), displays (for additional LCD drivers), non-standard components (for improving detection), or maybe T&M devices would be helpful.

[jakeisprobably]

   I am working on the link history of everything I have found here.
DIY Project Versions from Pages 1-50
Frenchie's Post
Moemoe's 1st Post
Moemoe's 2nd Post
Fabio Lucca's Post
Radio Flash's post
Bob808's Post
Tom666's Post

[madires]

What about creating a dedicated thread for your summary?

[siri_]

Is there some recommandations about available kits one can buy? I got one that broke and a second one that reads voltage 1V under the real value (and all surface mount).
It would be nice if someone has a recommendation for a kit up-to-date and reliable, prefereably through hole.

Also, is there a way to browse the 140 pages on one page? I am suscribed to another forum where there is this option.Then with ctrl+F it is easy to navigate through and find the information.

Thanks!

EDIT : JEEZ just saw someone asked the same question a couple posts earlier 

EDIT 2 : might as well post pictures of mine

Hi allI 

have one of those, and when I power it from a adjsutable power supply, it says "Bat. 10V OK". But i'm supllying it 9V, at least that's what's my multimeter (uni-t ut61E) says...

Is it something that could be a problem or it doesn't matter?

Thanks!

Sounds very much like a low accuracy resistor in the voltage divider. Does this also happen when you connect a battery?

No problem, it is ok and bear in mind that the values are for indication inly (ie could be way off as you have found)
[...]

I wouldn't say that. If it's way off, the automatic shutoff will not work right, and when running on rechargeable battery power it could mean discharging the battery beyond its limit or using the unit with voltages below the expected 5V on V_CC.

And when i plug it to a battery, when i want to turn it on, the screen flickers a bit, but it doesn't turn on.

[bitseeker]

Is there some recommandations about available kits one can buy? I got one that broke and a second one that reads voltage 1V under the real value (and all surface mount).
It would be nice if someone has a recommendation for a kit up-to-date and reliable, prefereably through hole.

With so many variations out there, it's kind of hard to make recommendations having not owned them all. Not long ago, it was pretty easy to recommend the red AY-AT version since it had all the bells and whistles and worked fine. Now, it seems there are several variants of it as well.

Also, is there a way to browse the 140 pages on one page? I am suscribed to another forum where there is this option.Then with ctrl+F it is easy to navigate through and find the information.

Click the Print button at the end of the last post on a page. That will not print the page, but open a printer-friendly version, which also contains all the posts in one stream.

[siri_]

Click the Print button at the end of the last post on a page. That will not print the page, but open a printer-friendly version, which also contains all the posts in one stream.

  awesome!!!!

thanks

[KapIngo]

I have bought an AYAT on ebay assembled it.. replaced the crystal with 16Mhz also compiled the latest 1.29m in AtmelStudio7 for 16mhz.. everything seems to work fine.. except I cant make the selfAdjustment to work correctly.. I read from madires post that I should measure a 220nF-1uF film capacitor 3 times then do the adjustment test... but everytime I do that an error comes out at the very end instead of done... doing the adjustment without measuring a capacitor completes without error...  also after the adjustment shorting any probes shows 0.01-0.05 ohms instead of 0 homs.. Is this expected or not.. thanks..

[all_repair]

I just bought this direct from taobao.  I think it is most suitable for me at this time.  Last I checked, it was not available on ebay or banggood.  They have an adapter that plugs into the 4mm.  The adapter has a ZIF socket and surface mount pad.

Edit:
This unit could run
https://github.com/svn2github/transistortester/tree/master/Software/trunk/mega328_st7565_kit

Is there a "m" version readily available for this kit?  Thanks.

[jakeisprobably]

Is there some recommandations about available kits one can buy? I got one that broke and a second one that reads voltage 1V under the real value (and all surface mount).
It would be nice if someone has a recommendation for a kit up-to-date and reliable, prefereably through hole.

With so many variations out there, it's kind of hard to make recommendations having not owned them all. Not long ago, it was pretty easy to recommend the red AY-AT version since it had all the bells and whistles and worked fine. Now, it seems there are several variants of it as well.

As far as I can tell there are only 2 common versions of the through hole AY-AT. The board that failed is an oddball surface mount variety of the AY-AT. The 2 common through hole versions are both documented in the Clones section of the current project pdf from KH. I ordered the latest version of these myself (w/ ST7735 controller).
   The minimum hardware for this project is an ATmega and 6 resistors. The most common failure is due to damaging the pins of the test leads when testing a capacitor with a charge. Some people have had surface mounted boards that had a bad capacitor on the board in the past, but it was a different version IIRC. Others have had bad solder joints on several occasions.
   If you want a perfect version you could always build your own. There are several links I posted above where others have done this with great results, and the tarball file will get you started.
   I am working on creating an extensive summary of this thread soon, and I'm working on a thorough tutorial on my clone build that I posted on the previous page of this thread, but I'm a gimp and super slow at everything.

Edit: adding picture index 1 of 3 for fun.
https://youtu.be/on1ZrWNt2Us

[perieanuo]

I have bought an AYAT on ebay assembled it.. replaced the crystal with 16Mhz also compiled the latest 1.29m in AtmelStudio7 for 16mhz.. everything seems to work fine.. except I cant make the selfAdjustment to work correctly.. I read from madires post that I should measure a 220nF-1uF film capacitor 3 times then do the adjustment test... but everytime I do that an error comes out at the very end instead of done... doing the adjustment without measuring a capacitor completes without error...  also after the adjustment shorting any probes shows 0.01-0.05 ohms instead of 0 homs.. Is this expected or not.. thanks..

I did the same mistake,it seems you have to measure 3-4 times the capacitor THEn you strart the calibration procedure.
it's well explained in the karl docs but who reads it...

regards,pierre

[mauroh]

I just bought this direct from taobao.  I think it is most suitable for me at this time.  Last I checked, it was not available on ebay or banggood.  They have an adapter that plugs into the 4mm.  The adapter has a ZIF socket and surface mount pad.

Edit:
This unit could run
https://github.com/svn2github/transistortester/tree/master/Software/trunk/mega328_st7565_kit

Is there a "m" version readily available for this kit?  Thanks.

At Banggood, they call it Hiland DIY M12864 Kit
I preferred this version because it has a nice case and it is faster compared to the latest AY-AT
Attached you can find the m-firmware 1.29 compiled for that hardware (8MHz and 16MHz)
I enabled also the servo function that I use frequently

Have a nice day
Mauro

[madires]

I have bought an AYAT on ebay assembled it.. replaced the crystal with 16Mhz also compiled the latest 1.29m in AtmelStudio7 for 16mhz.. everything seems to work fine.. except I cant make the selfAdjustment to work correctly.. I read from madires post that I should measure a 220nF-1uF film capacitor 3 times then do the adjustment test... but everytime I do that an error comes out at the very end instead of done... doing the adjustment without measuring a capacitor completes without error...  also after the adjustment shorting any probes shows 0.01-0.05 ohms instead of 0 homs.. Is this expected or not.. thanks..

Before the tester reports an error or success the adjustment values are displayed. Please post those values (with the cap measurements done before the self adjustment).

[KapIngo]

Before the tester reports an error or success the adjustment values are displayed. Please post those values (with the cap measurements done before the self adjustment).

something had change. If i use a 100nf film capacitor (doesnt show an esr value) and measure 3times success. However if i use a 680nf film capacitor (shows a 0.2ohm esr) and do the adjustment it wont even detect a short.. Just asks create a short circuit, I clicked continue and it shows the eeprom values and then displays an error. If i dont use a capacitor, adjustment will succeed. Attached bellow  are the values detected when it succeeds when using both 100nf capacitor and no capacitor the values are verry similar so i will only upload one image. I cannot upload a value for the 680nf capacitor since it wont even do  the adjustment test anymore its stuck at the create a short display then it displays an error.

[madires]

And if you create the short circuit after the cap measurement before running the self adjustment? The short circuit will trigger the main menu. Simply keep the probes shorted and run the self adjustment

[KapIngo]

And if you create the short circuit after the cap measurement before running the self adjustment? The short circuit will trigger the main menu. Simply keep the probes shorted and run the self adjustment

thanks madires now it works. If i allow the probe short to enter the menu.

what i did before is. i test the capacitor 3times and then enter the main menu. short the 3probes then finally click the adjustment. That didnt detect a short and created an error.