$20 LCR ESR Transistor checker project

[N1cho]

you have 1.29m compiled for 8m,test and feedback please
regards

Thanks

yes it work this time.  Nice. the selfttest does not need 100pf caps and others just need to short 1,2,3.

thanks

[perieanuo]

hi guys,
that's incredible they did it for 11.68 usd just the case missing,testers included,battery holder also.
how did they can produce this low?in this price you have the raw hardware,transport,seller value...
i know that's no new theme for anybody,but still surprise me!
i'd wish I can sell something like that in france at that price and still be in profit.wtf,even in romania...

http://www.ebay.com/itm/3-7V-of-inductor-capacitor-ESR-meter-DIY-MG328-multifunction-transistor-tester-C-/322546300660?hash=item4b1941f6f4:g:GyMAAOSws5pZOBXP

[madires]

yes it work this time.  Nice. the selfttest does not need 100pf caps and others just need to short 1,2,3.

You get a penalty point for not reading the README file. Please measure a film cap about 220nF up to 2.2µF three times before running the self adjustment for getting the offsets of the bandgap reference and analog comparator.

BTW, there's a hardware option for a fixed self adjustment cap for the ATmega 324/644/1284. In that case the offsets mentioned above are measured during the adjustment automatically.

[madires]

With ENCODER_PULSES set to 4 I can not get the tester to misbehave if I turn the encoder very slowly.
But with it set to 2 this behavior exists: "If I am very careful moving one indentation while in PWM mode it will count 2 steps"

You can also play with ENCODER_STEPS to change the feedback. A higher value slows down the rotary decoder.

[perieanuo]

You can also play with ENCODER_STEPS to change the feedback. A higher value slows down the rotary decoder.

I used 30 for ay-at clone seemed good enough for my encoder


Envoyé de mon iPad en utilisant Tapatalk

[Per Hansson]

You can also play with ENCODER_STEPS to change the feedback. A higher value slows down the rotary decoder.

I tried 30 and 48 without seeing that much difference TBH.
It's strange that it works quite well with Karl-Heinz firmware.
Otherwise I would suggest a hardware defect with the encoder.
Perhaps it still is, and his just happens to be a little less sensitive to the signal?

[madires]

A while ago I bought a bunch of the cheapest Chinese rotary encoders I could find for testing the read algorithm. One or two types were a little bit dicky, but still ok. The read algorithm enforces a proper Gray code sequence, no just reading one signal and then checking the second one to get the direction. The diameter of the knob is also important, since a larger diameter provides better control. The ENCODER_STEPS setting is meant to allow to finetune the feedback and to compensate the knob's diameter.

[jakeisprobably]

My very first tester with the rotary encoder and frequency counter options:

I have been researching this thread for weeks and I'm just getting into the last 50 pages in depth. The biggest mystery I have found in this entire thread:
 I have no idea why this post went largely unquestioned.

  First of all, kudos on the best looking custom designed project build and execution here. No one can call this a "cheap build." Regardless of cost this thing is NICE!
   From what I see, there are a few too many potentiometers, transistors, and unexplained extras like a whole extra IC on this bad boy. Maybe my eyes are messing with me but...are those RF choke beads I'm seeing on a few component leads? I think you've got some explaining to do here Mr Markus Especially on that little lie you've been spreading about how your a "Qualified Hobbyist." Your a pro at understating yourself and being respectful of everyone here despite repeating yourself a hundred times over to fools like me.
   I'm onto you though, only the most experienced top notch professionals create such a masterful execution of a project like this....and from the statement, "my very first tester with the rotary encoder and frequency counter" I'm going to go ahead and assume there are others before and after this! Sign me up for your masters class please. What would it take to get you to explain some of your unpublished tricks and mods?
:-)

[bitseeker]

Hehe, don't mess with the master!

Additional enclosures and related mods also at https://www.eevblog.com/forum/testgear/show-us-your-$20-transistor-tester-enclosures-and-mods/

[jakeisprobably]

Additional enclosures and related mods

   Oh I know :-) I have been putting together a whole lot more than what I have posted here already. The picture index is really a tool for me to break down this entire thread into something much easier to use. I have a content index I've been working on as well but that is much harder to share in raw form like pictures.

 I will add a collection of content to the enclosures thread soon. I've been building that file for a few days in parallel with others.

[hapless]

Just a bit of a heads-up: Some images that are linked from the posts here may be copyrighted or otherwise protected. You may wish to check that before including them into anything you publish just to be on the safe side.

[N1cho]

hi everyone,

i hope someone can help me out again.

i have a 2nd unit of this transistor tester that works with m328 colour kit firmware. but this unit is totally off and would not switch on at all. i have change the atm328 ic but still will not turn on. i tested all the R no problem the caps also all well. i test the s9014, s9012, tl431 and HT7550 but i think the HT7550 is the problem (attached) i look for the part but n/a can it be replace with 78L05. can it be other parts that cause the problem

thanks

[madires]

  First of all, kudos on the best looking custom designed project build and execution here. No one can call this a "cheap build." Regardless of cost this thing is NICE!

Thanks! I'm flattered

   From what I see, there are a few too many potentiometers, transistors, and unexplained extras like a whole extra IC on this bad boy. Maybe my eyes are messing with me but...are those RF choke beads I'm seeing on a few component leads? I think you've got some explaining to do here Mr Markus

It's nothing fancy, and you can find the schematics and PCB layouts in the SVN/git repo. That tester has a LM339 based PWM control for the LCD backlight. The potentiometer on the left is for the LCD's contrast, and on right is another one for the PWM. The PCB layout is designed for DYI, because the best tester is the one you've built yourself There aren't any ferrite beads. Originally that tester had a simple "test" push button which was replaced by a rotary encoder later on. The small PCB attached to the LCD is for the rotary encoder and frequency counter. The third potentiometer adjusts the sensitivity of the frequency input (in parallel with LCD's RS signal line).

Especially on that little lie you've been spreading about how your a "Qualified Hobbyist." Your a pro at understating yourself and being respectful of everyone here despite repeating yourself a hundred times over to fools like me.

Actually it's the truth I got a degree in EE but went into network architecture/engineering while doing EE as a hobby. Hence the "qualified hobbyist".

   I'm onto you though, only the most experienced top notch professionals create such a masterful execution of a project like this....and from the statement, "my very first tester with the rotary encoder and frequency counter" I'm going to go ahead and assume there are others before and after this!

It's really my very first Transistor Tester, followed by a few more of course. Also I got some testers and PCBs from users in Ukraine and Russia (Karl-Heinz shared them with me. He's a nice guy too!).

Sign me up for your masters class please. What would it take to get you to explain some of your unpublished tricks and mods?
:-)

A true magician never reveals his secrets

[madires]

i have a 2nd unit of this transistor tester that works with m328 colour kit firmware. but this unit is totally off and would not switch on at all. i have change the atm328 ic but still will not turn on. i tested all the R no problem the caps also all well. i test the s9014, s9012, tl431 and HT7550 but i think the HT7550 is the problem (attached) i look for the part but n/a can it be replace with 78L05. can it be other parts that cause the problem

Thou shall measure voltages! Check Vcc when the rotary encoder is pressed.

[carrascoso]

hi everyone,

i hope someone can help me out again.

i have a 2nd unit of this transistor tester that works with m328 colour kit firmware. but this unit is totally off and would not switch on at all. i have change the atm328 ic but still will not turn on. i tested all the R no problem the caps also all well. i test the s9014, s9012, tl431 and HT7550 but i think the HT7550 is the problem (attached) i look for the part but n/a can it be replace with 78L05. can it be other parts that cause the problem

thanks

I just repaired mine that was the same (dead) and was wrong T1 (S9012), replaced by an equivalent and working

[Per Hansson]

Here is how to setup a build environment on CentOS7 or RHEL7 (Red Hat Enterprise Linux)
In the optional repository EPEL we have already avr for our purposes.
The version provided is avr-gcc 4.9.2 which unfortunately produces files that are a little bigger than the previous release.
So if you are not on the limit size wise this version will work fine, but if not read on.

So since an older version is not available for CentOS7 on EPEL we have to try to find one.
Looking around we can see that for Fedora 19 avr-gcc 4.8.2 was released.
This is perfect because Fedora 19 is the same baseline system as RHEL7.
So login as a standard user on your Centos7 or RHEL7 machine and lets rebuild this source RPM:

Code: [Select]

wget http://archive.fedoraproject.org/pub/archive/fedora/linux/updates/19/SRPMS/avr-gcc-4.8.2-2.fc19.src.rpm
wget http://archive.fedoraproject.org/pub/archive/fedora/linux/releases/19/Everything/source/SRPMS/a/avr-libc-1.8.0-4.fc19.src.rpm

rpmbuild --rebuild avr-gcc-4.8.2-2.fc19.src.rpm
rpmbuild --rebuild avr-libc-1.8.0-4.fc19.src.rpm

su root -c "rpm -ivh /home/per/rpmbuild/RPMS/x86_64/avr-gcc-4.8.2-2.el7.centos.x86_64.rpm /home/per/rpmbuild/RPMS/noarch/avr-libc-1.8.0-4.el7.centos.noarch.rpm"Replace /home/per with your user used for building.
Happy building

[N1cho]

hi everyone,

i hope someone can help me out again.

i have a 2nd unit of this transistor tester that works with m328 colour kit firmware. but this unit is totally off and would not switch on at all. i have change the atm328 ic but still will not turn on. i tested all the R no problem the caps also all well. i test the s9014, s9012, tl431 and HT7550 but i think the HT7550 is the problem (attached) i look for the part but n/a can it be replace with 78L05. can it be other parts that cause the problem

thanks

I just repaired mine that was the same (dead) and was wrong T1 (S9012), replaced by an equivalent and working

i have replace 9014, 9012, tl431 but not the HT7550, putting the original HT7550 it does not have 5v out and s9012 heated up. i guess 7550 is the problem.

anyways back to my other unit. those anyone have firmware like the original i have the menu is:

1. Switch off
2. Transistor test
3. Frequency test
4. f-Generator
5. 10-bit PWM
6. C+ESR@TP1:3
7. continuous measurement resistance
8. 1-||-3 continuous measurement capacitance
9. Rotary encoder
10. SelfTest
11. Voltage test
12. FrontColor
13. BackColor adjust
14. Show data

pierre firmware works on mine but his does not have voltage test, i know the voltage test goes only up to 50v, but my module have the voltage test port.

pierre firmware menu are
pwm
zener
esr
freq counter
rotary encoder
ir detection
opto coupler ( what is this for?)
selftest
adjustment
save
load
show values
exit

when testing resistance why my module have 2 value the test point 2 is empty but there is value too. test point 1 and 3 show the correct resistance value . is there something wrong?

thanks

[upsss]

BTW, there's a hardware option for a fixed self adjustment cap for the ATmega 324/644/1284. In that case the offsets mentioned above are measured during the adjustment automatically.

Sorry, could you please explain, which hardware option?

[perieanuo]

hi everyone,

i hope someone can help me out again.

i have a 2nd unit of this transistor tester that works with m328 colour kit firmware. but this unit is totally off and would not switch on at all. i have change the atm328 ic but still will not turn on. i tested all the R no problem the caps also all well. i test the s9014, s9012, tl431 and HT7550 but i think the HT7550 is the problem (attached) i look for the part but n/a can it be replace with 78L05. can it be other parts that cause the problem

thanks

I just repaired mine that was the same (dead) and was wrong T1 (S9012), replaced by an equivalent and working

i have replace 9014, 9012, tl431 but not the HT7550, putting the original HT7550 it does not have 5v out and s9012 heated up. i guess 7550 is the problem.

anyways back to my other unit. those anyone have firmware like the original i have the menu is:

1. Switch off
2. Transistor test
3. Frequency test
4. f-Generator
5. 10-bit PWM
6. C+ESR@TP1:3
7. continuous measurement resistance
8. 1-||-3 continuous measurement capacitance
9. Rotary encoder
10. SelfTest
11. Voltage test
12. FrontColor
13. BackColor adjust
14. Show data

pierre firmware works on mine but his does not have voltage test, i know the voltage test goes only up to 50v, but my module have the voltage test port.

pierre firmware menu are
pwm
zener
esr
freq counter
rotary encoder
ir detection
opto coupler ( what is this for?)
selftest
adjustment
save
load
show values
exit

when testing resistance why my module have 2 value the test point 2 is empty but there is value too. test point 1 and 3 show the correct resistance value . is there something wrong?

thanks

Sorry.
If I don't forget I'll recompile one Monday with all stuff activated.I was almost sure voltage measurement is on...I'll check.
Regards Pierre


Envoyé de mon iPad en utilisant Tapatalk

[perieanuo]

BTW, there's a hardware option for a fixed self adjustment cap for the ATmega 324/644/1284. In that case the offsets mentioned above are measured during the adjustment automatically.

Sorry, could you please explain, which hardware option?

I think we have to mount a capacitor on the pcb and recompile with new option capacities bla bla bla.so the Uc knows he has an installed capacitor and do the calibration accordingly.
I'm wrong?
Regards Pierre


Envoyé de mon iPad en utilisant Tapatalk

[madires]

BTW, there's a hardware option for a fixed self adjustment cap for the ATmega 324/644/1284. In that case the offsets mentioned above are measured during the adjustment automatically.

Sorry, could you please explain, which hardware option?

A 470k resistor, a film cap (100nF up to 1000nF), an analog input and an I/O pin for switching the resistor. IIRC, it's in the 644 circuit in Karl-Heinz' documentation.

[jakeisprobably]

BTW, there's a hardware option for a fixed self adjustment cap for the ATmega 324/644/1284.....
...A 470k resistor, a film cap (100nF up to 1000nF), an analog input and an I/O pin for switching the resistor. IIRC, it's in the 644 circuit in Karl-Heinz' documentation.

Page 131 of this thread.

[N1cho]

By the way looking at the spec for capacitor measurement it start 25pf my module...  Anyone start from 1pf, i found 1 module start from 3pf-1mf. According to schematic program do the measurement, is it?

Sent from my E39 using Tapatalk

[madires]

k-firmware: 25pF - 100mF
m-firmware: 5pF - 100mF

100mF is the theoretical upper limit (we've tested up to about 20mF).

[perieanuo]

1.29M compilated with zener activated (voltage) for 8-16-20 mhz
seems to measure with some wrong offset (mine showed 9.9V for 9V input!!) haven't time to dig the voltage issue;anyway others seems fine (rcl,transistors).
if fact the only modif was zener activation,i never use this,just put my supply in crt limitation and a in-rush res and see the zener on my fluke,the 328 is for semiconductors and capacitors/inductances
next time i'll let you pay with winavr or another compiler,it's really easy
the 20 mhz is tested on my ay-at
regards,pierre