Show Us Your Curve Tracer

[EinErik]

With this new tracer, compared to my old lockyZ, this one is definitely better with no doubt
https://www.diyaudio.com/community/threads/new-tracer-is-coming.379759/page-5

[RichardM]

I would love to make this version of the curve tracer. I don't suppose you are willing to share the PCB/Scematics ? I have the ELV articles.

Regards

Richard

[Electron123]

What's the difference between a "transistor curve tracer" and a more basic octopus version (like this https://www.qsl.net/kd7rem/pdf/octopus.pdf)?  I know the fancy versions have more features, but are they both able to test the same components? Or is the basic one not able to test transistors?

[Cubdriver]

What's the difference between a "transistor curve tracer" and a more basic octopus version (like this https://www.qsl.net/kd7rem/pdf/octopus.pdf)?  I know the fancy versions have more features, but are they both able to test the same components? Or is the basic one not able to test transistors?

A transistor curve tracer allows you to characterize the transistor or other device - see how it behaves under different drive conditions.  The octopus is more a go/no-go thing that tells you it works, but not much more.

In this image of a curve tracer, each slanted line represents a different base current; the sweeps are the collector current as Vce is increased and decreased at each base current step.  In this image, the vertical scale is 5 mA/division, and the horizontal is 5 V/division.  The base current steps are 0.01 mA each.  Note that it has two sockets and the big toggle switch, it is set up to permit two transistors to be connected and by flipping the switch back and forth you can see how closely they are matched.



-Pat

[Cubdriver]

To elaborate on how the curve tracer works, it applies a base current (or gate voltage if testing a FET), then sweeps the C-E (or S-D) voltage from minimum up to whatever max you've set.  It then increments the base/gate drive by the step interval and sweeps the C-E/S-D voltage back down to zero.  Increments the drive again, repeats the low-to-high sweep, increment again and high-to-low.  Lather, rinse, repeat until the desired number of steps have been generated.  The beam on the screen thus traces out the current through or voltage across the transistor under test.

The curves for a PNP device are similar, but start in the opposite corner of the display as the polarities are reversed from those of an NPN (top right for PNP, bottom left for NPN):


Curve tracers can also characterize things like diodes and the strike voltage of neon lamps (sometimes used as voltage limiters/regulators).  In this instance, the device in the curve tracer is a color-changing LED, and the photo was taken as it was lighting two of its emitters to get a blended color.  Each of the colored LEDs inside has a slightly different forward voltage, thus the dual curves with slightly different voltages and currents, and the jumping between the two curves is caused by the internal IC in the LED switching the two different LED dies on and off alternately:


-Pat

[david77]

I would love to make this version of the curve tracer. I don't suppose you are willing to share the PCB/Scematics ? I have the ELV articles.

Regards

Richard

It's not that I don't want to share my PCB's but they're in one file married to the schematics and I'm not willing to put that online, copyright reasons, you know?

Maybe I can unmarry the layout and the schematics... I'll see what I can do.

[G0HZU]

I recently upgraded my curve tracer jig so it can produce accurate IV curves for diodes. The jig is homemade but I use a programmable PSU and a couple of decent bench DMMs to do the measurements. It's all controlled with a VB app in Windows.

The output data is then loaded into Excel as below and this system can test the diode down to a few nanoamps and compare the result to a theoretical curve as in the image below.

[croma641]

Hi, G0HZU,

what is Your curve tracer setup for other semiconducors ?

thanks

I recently upgraded my curve tracer jig so it can produce accurate IV curves for diodes. The jig is homemade but I use a programmable PSU and a couple of decent bench DMMs to do the measurements. It's all controlled with a VB app in Windows.

The output data is then loaded into Excel as below and this system can test the diode down to a few nanoamps and compare the result to a theoretical curve as in the image below.

[jord4231]

Here's my curve tracer 
https://youtu.be/Jb6N5H1kS2Y

[armandine2]

I have the Elektor magazine linked below - so no excuse

https://worldradiohistory.com/UK/Elektor/80s/Elektor-1988-10.pdf

for not having a simple curve tracer?

[tautech]

Not mine but member mawyatt had some time for experimentations of what he could do within the limits of a AWG and DSO.
https://www.eevblog.com/forum/testgear/fooln-around-with-dso-awg/

Reply #2 has his hand drawn setup and layout as an attachment.

[Calambres]

I have the Elektor magazine linked below - so no excuse

https://worldradiohistory.com/UK/Elektor/80s/Elektor-1988-10.pdf

for not having a simple curve tracer?

One year later (1989-12) Elektor showed a new instance of that curve tracer that was later cloned in the (in)famous Thai Kit. See my take on that kit in this very topic:

https://www.eevblog.com/forum/testgear/show-us-your-curve-tracer/msg3503702/#msg3503702

[TopQuark]

I'll put in my entry to the topic with probably the cheapest curve tracer mentioned in this thread.

I was once a teaching assistant for a mechatronics course in university during the pandemic lock down. It was not possible for students to access the lab gear on campus, all everyone had was an Arduino, some R and C and a couple of diodes from a basic component kit.

I was put in charge of designing a lab project for basic electronics, and I designed a fun "curve tracer" / "SMU" with the Arduino board. I have attached the lab manual I wrote for the project and a couple of test result plots. Mind you the students I taught were majoring in Integrated Systems and Design (not EE) and they were first or second year students, so the language of the lab manual was purposefully oversimplified.

What I hoped the lab would do was to instill in student's mind, the importance (and fun) of doing test and measurement, even if we were on a shoestring budget and locked down. I don't think many students understood or appreciated the lab project, but I think a few students got something useful out of the experience.

[mbrennwa]

Just stumbled over this thread. Cool stuff!

Here's my curve trace project: https://pypsucurvetrace.readthedocs.io

PyPSUcurvetrace takes a somewhat different approach than most other curve-tracer projects that require some specific hardware / board to work. PyPSUcurvetrace is a software toolbox that controls programmable power supplies to set and read the voltages and currents at the DUT. This means you can make a curve tracer from PSUs that are available off the shelf, and you choose the PSU units that suit your application: small transistors, power transistors, vacuum tubes, etc.

The PSUs don't need to be expensive "high end". For example, two RIDEN 6006P units can be had for about $300 or less, and will make for a very decent curve tracer setup! 

PyPSUcurvetrace also allows controlling the temperature of the DUT during curve tracing. I attached an example of an IRFP150 power FET measured at 30°C, 50°C and 70°C.

PyPSUcurvetrace not only allows measurement of the curves, but also has post-processing tools for high-quality curve plotting and to determine the DUT parameters from the raw data files (e.g., bias voltage/current for a given operating point, gain parameter, output conductance). More tools like curve matching/pairing of parts are in the works...

[THDplusN_bad]

Good Day,

Nice work, mbrennwa!

I have paused my activity here for some time - life happens...

At least, I have found some time to adopt my simple Python scripts for my Agilent N3280A component tester so it can also test MOSFETs now...
Plot taken from a BS170 N-ch. MOSFET attached. 

Cheers,

THDplusN_bad

[jonpaul]

tektronix 576, std, pulsed 100A front porch, many Tektronix and DIY sockets and adapters.
jon

[Edison]

Hi, I started building my tracker, what I could buy, I bought and ordered the rest of the parts, but the delivery company lost my shipment, so I got angry and got this - unfortunately the tracker arrived with a faulty function, managed to fix it, but not much - documentation no, all ICs have laser defaced markings. A repaired small TEK serves as a display.
A few photos - something from the repair of the oscilloscope and the resulting effect

[Neepa]

That's kinda cute. Using that tiny mobile scope as a screen.

Below my Pride and Joy with it's new to me NOS rack handles. Test Fixture on the top left and still missing the connection cables for it. But those are under procurement.
Always a treat pushing the powerbutton and seeing the monster coming to life with its flashing LEDs and that jet turbine mascerading as a fan in the back.

[Edison]

A beautiful piece of technology
I love these classic testers, but the size won't fit in my study, I'm unlucky, I have to miniaturize, I bought the Tek damaged, the connectors oxidized, the timer switch glued with hot glue and most importantly no probes - I couldn't let it die like this, it got a new power supply ( batteries are not needed) I restored it as best I could and it has been working like this for two years.

[0culus]

That's kinda cute. Using that tiny mobile scope as a screen.

Below my Pride and Joy with it's new to me NOS rack handles. Test Fixture on the top left and still missing the connection cables for it. But those are under procurement.
Always a treat pushing the powerbutton and seeing the monster coming to life with its flashing LEDs and that jet turbine mascerading as a fan in the back.

Very good. A very sophisticated bit of kit, with a lot of uses. I use my 4145B quite a bit. Make sure you make plenty of back-up boot disks though, since the instruments depends on them to be useful.

[alm]

Both the 4145A and B can be fitted with a Gotek or HXC floppy emulator. That would reduce the boot disk problem to making sure you keep an usb stick or sd card around with the right file. Here are some links. Apparently the main challenge is getting the cable pinout right, but 4145A and B are quite similar in that regard.

https://hxc2001.com/showroom/HxC_Floppy_Emulator_Semiconductor_Parameter_Analyzers_HP4145A.html
https://torlus.com/floppy/forum/viewtopic.php?t=1595
https://torlus.com/floppy/forum/viewtopic.php?p=24043&sid=90a698af4dbda5c4568c26813d8da371#p24043
https://torlus.com/floppy/forum/viewtopic.php?t=3878

I'd think you could also get it to work with a Gotek drive and the open source FlashFloppy firmware (cheaper), but I only found a brief mention of that.

[RoGeorge]

Not mine, it's from the 'xofunkox-scientific experiments':

Characteristics varistor


 

[gjames50]

I would love to make this version of the curve tracer. I don't suppose you are willing to share the PCB/Scematics ? I have the ELV articles.

Regards

Richard

It's not that I don't want to share my PCB's but they're in one file married to the schematics and I'm not willing to put that online, copyright reasons, you know?

Maybe I can unmarry the layout and the schematics... I'll see what I can do.

I'm curious about the overall costs of your version of the ELV KS 7000. Paul's DIY has an updated version of it, but the build cost for his is just under 1,000.00 USD. I posted a reply to the forum post located here: https://www.eevblog.com/forum/projects/1986-transistor-curve-tracer-worth-while-building/

I converted the Gratis documents from ELV to English (although I need someone who speaks/reads German/English to help verify it).

Your take on this is very interesting. What are the copyright issues on yours? Since ELV is giving this information away for free now, it must be for some other reason, correct?

Thanks!

[watchmaker]

Here is my Doc Brown (Back to the Future) version of the Thaikit. Curve Tracer, octopus for zeners and TCRL tester on one unit.  Makes for easy sorting.