this looks totally useful... and CHEAP!!

[karbomusic]

Edit-- Did another 9.  1 was bad.  Anyway.. similar results, but the MK-168 read between 30% to 70% high.  Avg. was 43% higher.

What specific types of transitors were tested?

@karbomusic:
Which tester do you have? (ebay-link?)

electrip

Yea, this one from the first post: http://www.ebay.com/itm/Mega328ESR-Meter-LCR-led-Transistor-Tester-Diode-Triode-Capacitance-MOS-PNP-NPN-/201087634115?

[italianguy63]

Yes

[electrip]

Mine does fine.

Tested one AC128 (TO-1 case, no Siemens marking, NOT TUNGSRAM) HFE in the 50s.
(HFE=68 @Ic=5,01mA Uce= ca 4V)

MK-168 HFE=55 Leakage=0,15mA
R.G. (*) HFE=54 Leakage=0,143mA
(*) read from DCApro Data Ib=4μA @Uce=8,5 Volt (9V- (2,472k*HFE*Ib))
from DCApro data MK-168 should be HFE=52 (Ib=9-10μA  Uce= 4,3-4,7V)

I guess one of your test setups is not properly working.

electrip

[Hemmel]

Still waiting for mine, can't wait !

[karbomusic]

Mine does fine.

Tested one AC128 (TO-1 case, no Siemens marking, NOT TUNGSRAM) HFE in the 50s.
(HFE=68 @Ic=5,01mA Uce= ca 4V)

MK-168 HFE=55 Leakage=0,15mA
R.G. (*) HFE=54 Leakage=0,143mA
(*) read from DCApro Data Ib=4μA @Uce=8,5 Volt (9V- (2,472k*HFE*Ib))
from DCApro data MK-168 should be HFE=52 (Ib=9-10μA  Uce= 4,3-4,7V)

I guess one of your test setups is not properly working.

electrip

It would be nice to know or see how it actually displays leakage.

[electrip]

It would be nice to know or see how it actually displays leakage.

Leakage (Base floating)

Leakage (Base grounded)

HFE and Uf


2SB202 choosen for guaranteed leakage.  

electrip

[karbomusic]

Leakage (Base floating)



electrip

That is nothing like mine displays and mine simply doesn't do leakage it appears. Thanks for posting that!

[Buzz]

Cool, mine turned up today. I'm looking forward to checking it out tonight.

[Ripdivot]

It would be nice to know or see how it actually displays leakage.

Leakage (Base floating)

Leakage (Base grounded)

HFE and Uf


2SB202 choosen for guaranteed leakage.  

electrip

I ordered the same one electrip has a few days ago. The display is not fancy but I felt it was worth the extra 20 bucks to get a case with jacks and be able to measure leakage.

[Buzz]

Had a muck around with it last night, what a great gizmo.

Got the one that doesn't do leakage, which I thought was a bit of a bummer.

Then it occurred to me how rarely i do Ge builds, and when I do I get my sets pre-measured from Chromesphere so no skin off really.

[italianguy63]

I ordered a 2nd one like RipDivots... I like the idea of having a case, and the test leads as an option.

I will probably sell my 1st one off...

MC

[Ice-9]

There now listed as Mega328 firmware. Has anyone received one of these versions and if so are all the options still available, I'm sure I read somewhere in this thread that the 238 lost some options (possibly leakage) has it been re added to the 328 firmware ?

[electrip]

There now listed as Mega328 firmware. Has anyone received one of these versions and if so are all the options still available, I'm sure I read somewhere in this thread that the 238 lost some options (possibly leakage) has it been re added to the 328 firmware ?

All new chinese testers seems to be AT Mega328.

The developer of the original firmware for the Transistortester AVR writes wrote in this thread
http://www.mikrocontroller.net/topic/248078#3723733 (german language)
that the chinese developers changed/adapted the software for the graphic display
and left out leakage and 'NPNp' (sic) recognition.
Maybe someone could try a thyristor with his tester if this function is available.

There will be further development by the original developers to support some graphic displays
without loosing functions but it is not easy to squeeze it into that little bit of memory.
The 'handicaped' testers could be updated if the hardware is set up for it.

Personally I will wait for that tester with all functions, enclosure, graphic display and LiIon-Akku,
it will surely come one day you can trust those smart chinese people.

electrip

[Buzz]

Hi, I got the same piece of kit as karbo and jimmy photon.

I noticed something odd about it that is way out of my comprehension level.

I tseted about 5 Q's in a row. They were all from the same bag of BC109s.

They all read 438 hfe right on the knocker. Well they are Si NPNs so they're going to be close, it just looked a bit too convenient.

So on the 5th one I left it in. Waited for the display to switch off then tested it again. Now the hfe reads 388.

Afew more reps and I can get the hfe to read as low as 288.

WTF?

[karbomusic]

Hi, I got the same piece of kit as karbo and jimmy photon.

I noticed something odd about it that is way out of my comprehension level.

I tseted about 5 Q's in a row. They were all from the same bag of BC109s.

They all read 438 hfe right on the knocker. Well they are Si NPNs so they're going to be close, it just looked a bit too convenient.

So on the 5th one I left it in. Waited for the display to switch off then tested it again. Now the hfe reads 388.

Afew more reps and I can get the hfe to read as low as 288.

WTF?

If I remove the transistor and put it back in while it is still on, I get 291 every time (thus far). Maybe something is holding some "charge" somewhere and you need to remove it and reinsert.

[armdnrdy]

Here is a link to PDF instructions for the most recent version I can find. This is not for the current version but...it may be of some use.
 
https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/ttester_eng106k.pdf

[electrip]

Here is a link to PDF instructions for the most recent version I can find. This is not for the current version but...it may be of some use.
 
https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/ttester_eng106k.pdf

http://ddl7.data.hu/get/0/7621720/ttester_eng110k.pdf

electrip

[J0K3RX]

I would guess the bogus readings are due to bugs in the source code, probably the "Checkpins" routine, dunno? I took a quick look at the code but it's quite complex... would take some time. The version 1.06 is a few revisions back since I found 1.10 to be the latest and fixes quite a few bugs and add new functions etc..

Is this what you guys have? If so, all files are available including the source code, eagle files etc... Also, there are change logs in each revision.
http://www.mikrocontroller.net/articles/AVR_Transistortester
If you are running Windows you will need to download and unpack the tarball with something that will extract .tar/.tgz files, plenty of freeware progs for that...
http://www.mikrocontroller.net/svnbrowser/transistortester/

Nice OSH board for the transistor tester... probably more floating around
https://oshpark.com/shared_projects/ir4NKmKE

I am all about DIY but this crosses the line for me!! Much easier to just buy it from ebay for the price of a couple packs of smokes...

These are ISP so you can probably upgrade the firmware if you have the right stuff...

[Hemmel]

Hey guys,

I got mine a few weeks ago but I haven't had time to play around with it yet.
I did but myself a plastic enclosure because I know myself very well and that small flat tester will get lost among stuff and probably get shattered.

I also bought a 9V wall-wart at 600mA, thinking I could plug it in when needed and basically do the same thing as with pedals, having a battery backup if I ever carry the tester around.

The wall-wart tests out at 11.2V (which I found very strange). Do you think it might damage the tester if I plug in 11.2V instead of a 9V battery ?

EDIT : I also thought of putting a 7809 regulator on the DC in ... that would probably be safer...

[karbomusic]

I also bought a 9V wall-wart at 600mA, thinking I could plug it in when needed and basically do the same thing as with pedals, having a battery backup if I ever carry the tester around.

Just an FYI that I still have the same 9V battery I put in when I got mine and it has only dropped 20-30 MV since I got it. IOW, the battery seems to last quite a while and it always displays the battery voltage when the test runs.