DIY Curve Tracer (analog) - Page 1
Forum section: electronics / testgear

author: Dbldutch
author_rank: Regular Contributor
timestamp: November 14, 2021, 08:52:39 pm
content: We have a small team that is building a DIY Curve Tracer. Not a Tek577, but a lot better than anything we found that comes close. We are close to the final stages and have a fully operating CT that I'm making measurements with.If you're interested, have look on my blog. Eventually everything will be shared but we'll wait until we have finished the project.https://www.paulvdiyblogs.net/2021/03/building-curve-tracer-version-3.htmlMy blog is not very good for handling comments and questions so please leave them here.Enjoy!

author: rodpp
author_rank: Frequent Contributor
timestamp: November 14, 2021, 10:14:38 pm
content: Congratulations! I don't read your entire blog post yet, but it seems a very comprehensive work.It would be nice to summarize the technical specifications of your Curve Tracer, maybe using the Tek 576 or 577 datasheet as template.

author: Dbldutch
author_rank: Regular Contributor
timestamp: November 19, 2021, 12:51:59 pm
content: Rodpp, I just finished a first attempt by listing the overall specifications.

author: rodpp
author_rank: Frequent Contributor
timestamp: November 20, 2021, 05:45:39 am
content: Excellent, very good specifications section!Your Curve Tracer is really impressive. Going up to 200V and up to 2A, with all that controls, it cover a vast set of component tests, certainly covering the operational point for the majority of electronic circuits.Congratulations for the well done work!

author: bob91343
author_rank: Super Contributor
timestamp: November 20, 2021, 06:49:31 am
content: While you didn't do this as a profit making, potentially large quantity product, I would scarcely consider it DIY. It's certainly beyond my capability to construct such a unit, at least in terms of how much my time is worth to me.I admit it's noteworthy and an excellent job so let me compliment you on doing it so well, including documentation.Perhaps you should consider marketing it; how much might it sell for?

author: Dbldutch
author_rank: Regular Contributor
timestamp: November 20, 2021, 08:04:12 pm
content: Hi bob91343,Thanks for the compliments.I have to admit that the project started out as a DIY one, but as time went by and we added more features and improved the reliability, it could be out of reach for some to build this instrument. We are doing our best however to still make it DIY by avoiding special parts and make an effort to stay away from using packages smaller than 0802 with the exception of few small Opamps but even they have leadsWe have no plans whatsoever to get into the manufacturing business ourselves, but given enough interest there might be an outfit willing to commercially exploit this. Another possible option is to let board manufacturers like JLCPCB produce the boards and stuff them for you with whatever parts they carry. We have not looked into this ourselves though. At the moment Mark and I build everything ourselves and by hand.We will produce BOM's with all the details when we're done and are carefull about WW sourcing.

author: bob91343
author_rank: Super Contributor
timestamp: November 21, 2021, 01:51:01 am
content: I would be interested in the BOM and a prefabricated PC board. The bottom line cost of all items is important; if I had the parts I would consider assembling it as long as the outlay isn't too much.

author: THDplusN_bad
author_rank: Regular Contributor
timestamp: November 22, 2021, 02:18:25 pm
content: Hello,I am very impressed by your work, Paul. Well done.! And thanks for taking your time for the detailed write-up in your blog.Cheers,THDplusN_bad

author: graybeard
author_rank: Frequent Contributor
timestamp: November 22, 2021, 06:57:45 pm
content: Very nice work.I think near the end or your blog your MOSFET was oscillating.I have had success suppressing most (but not all) device oscillations with a combination of ferrite beads places as physically close to the device as possible. I like to usefair-ritematerial 43 closest to the device followed by a material 73 bead. The 43 material is insulating, but the 73 material is slightly conductive.

author: Dbldutch
author_rank: Regular Contributor
timestamp: November 22, 2021, 08:42:52 pm
content: Hi graybeard, you mean the damaged MOSFET's? That could very well be, beside the fact they they did work strange with high voltages. We already use simple 10nH inductors in series with the Base/Gate pins to supress oscillations as we did on our Rev2 instruments. We will need to revisit this when we have the final layout, something we're working on right now.Thanks for the bead info, they will be better than what we have now.

author: David Hess
author_rank: Super Contributor
timestamp: November 24, 2021, 05:32:10 pm
content: Curve tracer fixtures from Tektronix typically include ferrite bead on all connections at the device, as shown below.The design of pin drivers for curve tracers is interesting. It is difficult to achieve wide dynamic range without excessive range switching and I am still working on the best solution to this problem.

author: graybeard
author_rank: Frequent Contributor
timestamp: November 27, 2021, 08:52:14 pm
content: Get aferrite bead kitand experiment. The bead order I gave you (43 closest to the device and then 73) works best, but the size you need is best determined by experiment.

author: Dbldutch
author_rank: Regular Contributor
timestamp: July 14, 2022, 08:31:21 am
content: We have finished the design of the Curve Tracer and published all files required to build an instrument yourself.Here is the link to the description:https://www.paulvdiyblogs.net/2022/06/the-vba-curve-tracer.htmlAnd here is the Github repository:https://github.com/paulvee/VBA-Curve-Tracer

author: David Hess
author_rank: Super Contributor
timestamp: July 14, 2022, 06:09:20 pm
content: Nice knobs.

author: Dbldutch
author_rank: Regular Contributor
timestamp: July 18, 2022, 12:30:15 pm
content: Hi David,I'm sure you recognized them to be from Tektronix T&M equipment.For me, they were probably the best looking quality knobs ever made.

author: bd139
author_rank: Super Contributor
timestamp: July 18, 2022, 12:55:13 pm
content: Until they crackSeriously impressive project though. It’s a missing product on the market now without spending serious money on more generic kit. I was actually going to design and build one myself. This may quell that desire. I will add it to the project queue.

author: David Hess
author_rank: Super Contributor
timestamp: July 18, 2022, 05:53:50 pm
content: Quote from: Dbldutch on July 18, 2022, 12:30:15 pmThey are nice. I have a whole collection from broken plug-ins but have never put them to use except as spares. Until some time in the 90s, Tektronix manufactured their own hardware and did an excellent job, except of course for matching the expansion of the plastic to the metal inserts.

author: mlloyd1
author_rank: Contributor
timestamp: July 18, 2022, 06:13:58 pm
content: Great looking project with pretty good performance.You guys did a great job!Thanks for sharing.mlloyd1

author: tkamiya
author_rank: Super Contributor
timestamp: July 22, 2022, 06:10:17 pm
content: Excellent work! I am seriously considering duplicating a unit for myself.

author: MustardMan
author_rank: Contributor
timestamp: November 29, 2022, 01:52:13 am
content: A nice unit indeed, and something I would like to add to my bench. Unfortunately having to source all the parts & build it puts me off.Anyone out there willing to build one and on-sell it?

author: Eebigdog
author_rank: Newbie
timestamp: December 20, 2022, 06:03:25 pm
content: I would be interested in getting a board set for this project.Please email me with any details.Thanks