Show Us Your Curve Tracer

[KungFuJosh]

All the popular guitar amp tubes.
Cool! 

Can you switch between triodes?

I ran a trace on a new production Tung Sol 12AX7. Here's the plot:



The GUI window is resizable, so you can make the plots full screen. The other 3 screenshots attached below are my monitor's resolution. They have both or each individual triode.

Thanks,
Josh

[Cubdriver]

Yeah, I definitely want to build one of these!

-Pat

[Johnny10]

Very Nice!

[KungFuJosh]

For anybody interested, I'm going to order some more PIC chips to program, and then I'll get 5 to 10 kits ready. Initially they won't have anything on the boards, so I suggest anybody interested has or develops some SMT skills before proceeding with this set. For the future, I'm getting quotes on PCBA service to cover the 5 smaller SMT parts (there's also a couple larger ones setup for easy hand soldering that don't need any special skills).

Thanks,
Josh

[Shock]

Please start a thread in the projects forum.

[Cubdriver]

For anybody interested, I'm going to order some more PIC chips to program, and then I'll get 5 to 10 kits ready. Initially they won't have anything on the boards, so I suggest anybody interested has or develops some SMT skills before proceeding with this set. For the future, I'm getting quotes on PCBA service to cover the 5 smaller SMT parts (there's also a couple larger ones setup for easy hand soldering that don't need any special skills).

Thanks,
Josh

I'm definitely interested.

-Pat

[KungFuJosh]

Please start a thread in the projects forum.

Done. Here's the new thread: https://www.eevblog.com/forum/projects/project-vacuum-tube-curve-tracer-(the-futracer)/new/#new

Thanks,
Josh

[lugaw]

SMU gang represent!

(glances to the left, then to the right -- coast is clear, SPA gang isn't around yet)

Custom 3D printed feet and "panel" (bar) turn this SMU into a convenient bench tool. Actual work is done in jupyterlab / holoviews / pyvisa-py.

Please share the STL of your custom feet, I need it on my picoammeter. Thanks!

[Roehrenonkel]

Hi,
 
At https://jacmusic.com/Tube-testers/index.html you can find under No.10 most of the digital/PC-controlled curve-tracers for tubes.
Have tried some but nothing is perfect. What i wanted is more accuracy and flexibility.

More than the kit that calls itself "professional tube testing system" in germany.
Not even grid-current measurement possible there. Nice software but Windows-only.

So i put some VXI-modules (16 Bit DAC +-40V, seven voltmeters and a PSU) together
with a selfmade relay-matrix 4-In 16-Out and some GPIB-Powersupplys.
For now controlled by Agilent-HP-VEE, would like to do that from my Raspberry.

Have also checked transistors and LEDs with it,
just depends on the controll-software and power-sources.

[jjoonathan]

SMU gang represent!

(glances to the left, then to the right -- coast is clear, SPA gang isn't around yet)

Custom 3D printed feet and "panel" (bar) turn this SMU into a convenient bench tool. Actual work is done in jupyterlab / holoviews / pyvisa-py.

Please share the STL of your custom feet, I need it on my picoammeter. Thanks!

Whoops I must have missed this last time. Here they are!

[THDplusN_bad]

Good Day,

this is not about a self-made curve tracer, but those interested in PC-based measurement equipment might be entertained by this.

I use a "Electronic Explorer" device from Digilent/US for a few years now. This is basically a simple USB-connected, FPGA-based multi-instrument that integrates an 4-channel oscilloscope, 2-channel arbitrary waveform generator, simple logic analyzer and a power supply in combination with a solderless breadboard. I primarily use it for the quick evaluation of simple circuits whenever needed. It also supports Bode plots etc. The "Electronic Explorer" hardware platform is outdated by now, but it still supported by Digilent's "Waveforms" software. If any Digilent employee reads this: Thank you for doing that.

Digilent (which is a NI company, by the way) has released a "transistor test adapter" some time ago. That is an add-on for their more recent USB-based instruments such as the "Analog Discovery 2" device. https://digilent.com/reference/test-and-measurement/transistor-tester-adapter/reference-manual
And so they have also added the required settings in form of a virtual curve tracer to the mentioned "Waveforms" software. I have created my own version of a curve tracer in Waveforms some time ago (this is primarily a configuration of the two-channel waveform generator, and not too hard to do). However, I have tried this new "tracer" configuration and attached are a few plots I have generated from a standard BC337-40 BJT today. (Side note: The noise level results from the wiring and the two curves on the right are artefacts).

It's quite nice to see how the curves are generated, a large data set gets acquired very quickly and how the data can be exported to a database, MS Excel etc.

Also, the software offers a 3D-view of the collected data that is quite fascinating. https://digilent.com/reference/test-and-measurement/guides/waveforms-curve-tracer

This is not a real curve tracer in terms that the voltage and current supplies are limited (+/-10V, 35 Ohms output impedance each channel for the "Electronic Explorer"). But it's an excellent starting point into the fascinating world of component testing. It's also certainly good enough to match some small signal transistors /BJTs or FETs/ as well as diodes.

Have a great weekend, all.

Cheers,

THDplusN_bad

[6SN7WGTB]

I built the Paul Carlson curve tracer, but modified to be (a) SMD and (b) have a power op-amp to provide a split rail supply from a single external PSU.

I use it for go/no-go testing in circuits.

Shown below, inside and out, and with a germanium diode under test.

[Martin72]

Nice work ! 

[Electro Fan]

Thanks to rstofer's posting in this thread:
https://www.eevblog.com/forum/beginners/oscilloscope-triggering-from-function-generator/msg4058536/#msg4058536

I came across this link to a thread on a curve tracer project:
https://circuitcellar.com/research-design-hub/create-your-own-i-v-curve-tracer/
- another nice inexpensive combination of hardware and software

[deemarkay]

Here's my copy of the ELV KS7000. It works quite well and has turned out to be a useful tool for the workshop when fixing stuff.

Hooking up devices with clip leads was not only very messy and annoying, it also resulted in nasty oscillations. So I decided to go the
Tektronix route and made up a testfixture. So far I've got this one that works for small & medium power transistors. I've got parts on order to make another one for TO3 packages. This works very well so far.

Certainly no Tek but ok for me.

Looks really nice! The testsocket adapter, frontpanel and all is very shmick!
I'm currently in the process of collecting all the parts for a build of my own and having trouble sourcing some components. Especially the relais are a mystery and it turns out even replacements for the transformer  are no easy feat to aquire. Could you share how you solved parts sourcing problems on this build?

[david77]

Yes sure I'll help.

I use two transformers. One is 2x15V 0,5A for the OP's and CMOS stuff and a big toroid that used to give 2x44V output and I've added a few windings to get it up to 2x60V.

Ah yes, those Siemens Relais are long obsolete but not really necessary. Just use regular Relais, there's nothing special about them.

[basinstreetdesign]

Digital, smidgital...I've probably posted about this before but here is my home-built tube curve tracer.  I used it to answer a question about the biasing of some 6AU6's in a stereo amp I was making.

This is the first attempt at making it, which proved successful enough.
https://www.instructables.com/Tube-Curve-Tracer/

Then some added functionality came a bit later:
https://www.instructables.com/Tube-Curve-Tracer-Ver-11/

A word about my build style.  I don't like to spend a lot of money.  So parts are usually drawn from my glory boxes and whatever I have on hand.  If I can find enough workable stuff then it may happen that I spend exactly $0 on a project.  And so it was with this one.

Included is a shot of it in use and a shot of the HP 1741A showing the curves for one triode in a 12AX7 tube.

[deemarkay]

Yes sure I'll help.

Thanks! 😎

[RoGeorge]

This is from a Python script sending SCPI commands to a Rigol DP832 power supply, in order to browse/measure Vgs, Vds and Ids of a PHP45N03LT TrenchMOS.


https://www.eevblog.com/forum/testgear/rigol-dp832-power-supply-as-automated-curve-tracer/

Does Python qualifies as a curve tracer? 

[caulktel]

I bet not many have seen my curve tracer. https://www.nutsvolts.com/magazine/article/build-an-oscilloscope-octopus

Joel
N6ALT

[branadic]

I have the updated version KLS 2.0 of DL4JAL's curve tracer, that recently got the upgrade to PIC18F46K80. The board rev2.0 with the improvements is discribed here:

https://www.bartelsos.de/messtechnik/untersuchungen-an-bauteilen/kennlinienschreiber

Attached a measurement of a 2SK170.

-branadic-

[David Aurora]

Anybody else got one of these? I picked it up in a deceased estate sale a while back, it seemed to be mid-repair (half the screws missing, cord cut off etc). Haven't been able to find any record of it ever existing, let alone schematics.

I cleaned it up a bit at the time and then kind of forgot about it because it needed all new switches and I couldn't be assed fully disassembling it, but I finally changed them over tonight after work and the thing is now 99% working (the switches were so bad that you kind of had to hold them in place to get any display and even then it was a crapshoot). All that's left to do now is troubleshoot the step generator, it doesn't put out anything on voltage mode.

I've got a Tek 576 arriving soon so I don't imagine I'll bother going much further with this one, but it seems way too nice inside to waste so it'll likely get passed on to my assistant or something if I can work the last bugs out of it

[Electro Fan]

New video from W2AEW on curve tracing.  As usual from W2AEW his teaching is outstanding; his videos on a scale of 1 to 10 are typically about a 12 to 20 or better for clarity and conciseness.

[RoGeorge]

This yellow alligator showed up once, while identifying the type of photodetector from a former punched-card reader.  The curve tracer was improvised from a Rigol DG4102 DDS generator, a scrapped transformer and a Rigol DS1054z oscilloscope in XY mode:



The bar of 12 optical sensors from 1975 proved to be made out of NPN phototransistors.

[Electro Fan]

RoGeorge - very nice project!

https://www.eevblog.com/forum/testgear/rigol-dp832-power-supply-as-automated-curve-tracer/