$20 LCR ESR Transistor checker project

[madires]

Calibración is the adjustment value for the internal RC oscillator. You don't need to update or change that value.

[Pukker]

For ATmega328 with external 8MHz crystal:
Low Fuse: f7
High Fuse: d9
Extended Fuse: fc

Is this setting for 16MHz too?

Thanks for answering.

[stj]

yes

[Pukker]

Thanks STJ.

[turbochris]

QUESTION!- I have a few lipo cells with protection circuits and some of these micro USB charge controllers with 9 volt boost converters built in. I have the newest AY-AT PCB based tester. I'm going to put the lipo and charge controller/boost converter on it. How can I run the vbat signal that goes to R1 directly to my battery so i can see battery actual battery voltage and not the converter output voltage? Would I need to add another transistor like T1 between the battery and sense circuit to keep the voltage divider on the sense circuit from killing the battery?

[perieanuo]

QUESTION!- I have a few lipo cells with protection circuits and some of these micro USB charge controllers with 9 volt boost converters built in. I have the newest AY-AT PCB based tester. I'm going to put the lipo and charge controller/boost converter on it. How can I run the vbat signal that goes to R1 directly to my battery so i can see battery actual battery voltage and not the converter output voltage? Would I need to add another transistor like T1 between the battery and sense circuit to keep the voltage divider on the sense circuit from killing the battery?

You won't kill a battery with a divider with correct values. Unless you don't use the charger for months. Avoid charging the battery with the tester connected. That's all

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk

[indman]

QUESTION!- I have a few lipo cells with protection circuits and some of these micro USB charge controllers with 9 volt boost converters built in. I have the newest AY-AT PCB based tester. I'm going to put the lipo and charge controller/boost converter on it. How can I run the vbat signal that goes to R1 directly to my battery so i can see battery actual battery voltage and not the converter output voltage? Would I need to add another transistor like T1 between the battery and sense circuit to keep the voltage divider on the sense circuit from killing the battery?

The decision from the user Vepr from the Russian forum vrtp.ru  http://vrtp.ru/index.php?showtopic=25020&view=findpost&p=745685 
"I used  of the boost converters on 5v, having soldered in it to the place of IC1 7550 (stub. 5Volt).
I replaced the R17 220 resistor of Ohms with the low-impedance 0-50 Ohms (I increased illumination brightness)
The R18 3k3 resistor replaced with free 220 Ohms.
In a code I corrected a supply
CFLAGS + = - DBAT_OUT=10
CFLAGS + = - DBAT_POOR=3300
The module for accumulator charging with protection set in a rupture of the power connector.
As a result to the T1 emitter comes 4 Volt from the accumulator, on an output IC1 - 5 Volt, need for the supply switch disappeared..."

[jakeisprobably]

Howdy,
https://youtu.be/9cg7pBUUv94

I'm still having too much fun with the simple stuff

[aabbcc]

So I got the Dainu TC-1, is it accurate enough to match transistors for vbe (need to match a bunch of BC547 & BC557).

I tried measuring the same transistors a few times and it almost every time gave me different vbe lol, from 678-692 :S


https://www.banggood.com/DANIU-3_5inch-Colorful-Display-Multi-functional-TFT-Backlight-Transistor-Tester-p-1083042.html?rmmds=search

[stj]

variation is probably down to the crap contacts in the green chipsocket

[perieanuo]

Maybe also temperature related for small transistors if you put your fingers maybe changes vbe a little. I'll try myself to verify...

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk

[jakeisprobably]

I tried measuring the same transistors a few times and it almost every time gave me different vbe lol, from 678-692 :S

  The AVR Transistor Tester design isn't intended as a precision device, and no clone to date uses the 0.1% resistors or the 0.1% voltage reference specified in the documentation. The software is very impressive for it's capabilities with simple hardware.
  Like most clones you probably have a relatively large difference between the probing resistors on each ADC sensing pin. The software can only have one value attached to the 680R and 470k probing resistors. This is why the design specifies 0.1% resistors. In this case it is the tollerence that matters, not the accuracy. Each 680R/470k resistor needs to be closely matched, but it doesn't matter if the resistance is extremely accurate. The variance between channels is important. Your voltage reference is also creating accuracy error because the reading that the TT is giving you assumes you've used a 2.5 volt reference with 0.1% accuracy. The TL431A reference used in clones has a tolerance 10 times larger than the specified accuracy of the design as listed in the documentation.
(Edit: A cheap replacement voltage reference option is here. I haven't tested them yet, but that's what I ordered to try on an SMT clone. The pinout is different than the TL431A, but the LM4040 DS says you can leave the Vref pin floating, so it should work by simply soldering it diagonally without a jumper or other mods.)

I was under the impression that we need to stair step the voltages to gather a more 3 dimensional understanding of transistor Hfe and Vbe curves for matching. If you have an oscilloscope Allen has some great tutorials on different ways to build a simple curve tracer on his A2AEW YouTube channel. Specifically his videos numbered #232, #197, and #49.

   My curiosity about curve tracers is if there is any potential to add one as a project option to the AVR TT. I know people have created "Arduino" oscilloscopes that will run on controllers as small as the ATmega8. I wonder if we use one or two 74HC4052's (dual 4 channel analog MUX/DEMUX) and reconfigure the Zener threshold DC to DC boost converter, could we create a curve tracer option?
   I've seen one project on YouTube that used an Arduino oscilloscope reconfigured in a XY mode to create a curve tracer. (Thinking out loud here) I wonder if a 4052 could be used to control a feedback resistor network on a DC converter while expanding the AVR's I/O and protecting it from over voltage/current.

[madires]

Might be possible with the additional I/O pins of the ATmega644/1284. There was an idea to support higher test voltages than just 5V (and higher test currents), but that would require an external switching network. For the sake of simplicity we've dropped that idea. IMHO, it would make more sense to build a curve tracer front-end for a scope.

[jakeisprobably]

I still need to figure out a way to organize stuff on my computer and upload that to Git but here is the start:
https://github.com/Upcycle-Electronics/AVR-Transistor-Tester

I added some of the PDF's I have created, some were posted on here, some are not, some are works in progress. Once I figure out how to reorganise all of the KiCAD parts libraries I have created, I'll try to upload the active project files so anyone with KiCAD can goof around with them if they want

[cbc02009]

Hi guys,

I recently bought this kit (https://smile.amazon.com/gp/product/B01HCXG9YS/) but I pulled a stupid and burned the arduino bootloader on to it. (i had to us it as an ISP to recover a bricked arduino mega, and somehow forgot it would wipe the program already on it  ). I've been trying to figure out how to get the program back on the chip, but I'm really having trouble figuring it out. If there's anyone that could point to some help, or walk me through it, I would really appreciate it.

[imidis]

Is it unmodified?

If so. Try burning these via ISCP https://github.com/svn2github/transistortester/tree/master/Software/trunk/mega328_color_kit

Can use AVRDudess or whatever your choice is for avrdude usage.

[jakeisprobably]

I've been trying to figure out how to get the program back on the chip, but I'm really having trouble figuring it out. If there's anyone that could point to some help, or walk me through it, I would really appreciate it.

I've been having trouble making these links work with copy and paste. Maybe they will work here. If not I have included page number references. I've been working on a tutorial video on programming but I need a few parts in the mail to finish a hacked together USBasp programmer enclosure first...so I'm no help ;/
USBasp by Tom666 on page 60
Arduino ISP by Tom666 on page 59
Arduino ISP by Flywheelz with AY-AT example on page 103 (continued on 104)

[cbc02009]

Is it unmodified?

If so. Try burning these via ISCP https://github.com/svn2github/transistortester/tree/master/Software/trunk/mega328_color_kit

Can use AVRDudess or whatever your choice is for avrdude usage.

Thanks, I'll give it a try this afternoon. Much appreciated.

[nakcho]

If flashing new firmware, do not forget to set the FUSES correctly, please!


SVN firmware repository "mega328_color_kit" folder:
https://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_color_kit/

I still use the SVN 700 compilation from STJ (attached).

again ... excuse my gnorancia .... I'm in full fight with this ... I attached an image of the fuse settings please help me ... install the firmware and only the voltage appears ... and then it turn off I think it is due to lack of fuse settings --- you help me with the correct configuration of the fuse? the crystal is 8Mhz

HELLO ... I HAVE
2578AY-AT AND MY ORIGINAL FIRMWARE WHEN INICIAVA DECIA 1.12K ... WHICH WOULD THAT FIRMWARE WOULD .. I WOULD LIKE TO INSTALL THE SAME AGAIN ... SINCE THAT ME WORKSAVE PERFECT ... YOU COULD PASS ME THE LINK ... PLEASE TO THAT VERSION?

[frozenfrogz]

I drew a case for the GM328A model and upped it here on Youmagine.
It is the first version and may need some refinement to give better printing results for the top shell.
My first print was OK-ish but needed some putty to fix the surface (printed upside-down with support).

[stj]

 

[nakcho]

Good morning I need a little help that I do not know what to do ... I've tested the firmware AY-AT ESR tester (SVN749) .. first then after recording the frimware I turn on the tester is the screen in blue 1 min 30 sec apox then aprace some data as the battery and version I guess ... after that the word short probe appears! After shorting pins 1-2-3 starts to do some kind of test .... then it remains in CO for a while .. after that it remains with the screen in 100nf (I put a capacitor of 100nf). but then nothing comes out ... not even pressing the reset button or moving the decoder ... any idea
'It has a crystal of 8mhz ... will it be for that reason what takes so long? between one screen and another? ... if so, I would only open it to change for a 16 mhz help please ... I need to recover

[stj]

try calibrating using a 220nF capacitor.

[ncclabs]

I designed my own style 

[bitseeker]

Welcome to the forum, ncclabs. That's a nice clean "case." I'd probably mount the top PCB higher so that the ribbon cable on the LCD could be covered. It'd give it some protection and look cleaner.