Curve tracers

Reminding myself that, yes, Google is my friend... this thing looks not half-bad:

It's still more _desktop_ than not and, so far as I can tell, doesn't use USB nor did I easily see any means of downloading the gathered data into a PC (without a digitizing scope, anyway.) But I've seen him posting in the LTSpice group and elsewhere and he seems to be very courteous, generous to a fault, and struggling hard to get all the important details of his work done correctly and with understanding.

Jon

Huntron tracker.

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Many thanks,

Don Lancaster                          voice phone: (928)428-4073
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That's why it's only "not half-bad." :-) Still a lot better than hugging the boat anchor that is a Tek tracer around and all; I think the limitations of his design are some I can live with.

Thanks for your input...

For us Spice modeling aficionados it'd be nice if the data could be not only ported to a PC but digitized as V-I pairs.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
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I love to cook with wine.      Sometimes I even put it in the food.

Joel Kolstad wrote: > Thinking back to that thread about portable USB-based (faceless) spectrum > analyzers... is there such a thing as a small, reasonably portable

*curve > tracer* out there? All the curve tracers I've met are those huge Tektronix > beasts, and it seems as though there ought to be something a little more > portable & cheaper & readily computer-interfacable... >

Just this morning I was using my Heathkit 1121 to check some bi-polars for a video monitor. Its connected to a Tek 465 but I wonder if it could drive into an A-D to get into the PC. As for tracers for the PC, how many folks use individual transistors?

GG

1) Anyone doing a design where ICs to perform the function don't exist -- and the volume involved doesn't justify making one (at least where I work, this happens *all the time*... I imagine it does for folks like Win as well...) 2) Folks like Joerg who realize that many a quarter IC can be replaced with a five cent discrete circuit. 3) Those doing high-power designs where discrete devices still dominate.

I would imagine the IC guys do their "curve tracing" using a handful of FETs (or whatever) on a test die being probed by something like a Cascade Microtech probe station, a network analyzer, and fancy modeling software... at that level everything is huge and expensive anyway.

4) A customer of mine used a curve tracer to check the connectivity of signal lines to BGAs. Not for mass production, but for lab prototypes. You can clearly see the protection diodes to vcc and gnd. Removed a lot of doubt if sth. did not work as expected.

Gerhard

Here's a cheap way if you have a GPIB card in your PC: go to eBay and buy two HP 59501A D/A converters and a HP 34xx digital voltmeter. The D/A's give you the base and collector drive voltages. The 34xx you use to measure the collector current. A 20-line computer program can cycle the D/A's through their ranges and gather the data. With some careful shopping you can do it all for under $100.

"Ancient_Hacker" wrote in news: snipped-for-privacy@d56g2000cwd.googlegroups.com:

TEk may still make their 370(Sony/Tek)curve tracers,IIRC,one of those had a

3.5" floppy drive for storing the displays.they were not huge units like the old 576 or 577 curve tracers.As I recall,one of them was smaller than a mini-tower PC.

--
Jim Yanik
jyanik
at
kua.net

That is,if you do not have to *pay* $100 per GPIB cable...

I forgot about that part. Find some 24-pin IDC connectors and some shielded flat cable and make your own daisy-chain cable.

In the 70s - 80s I worked for a large mainframe computer company. The models were based on ECL technology. Someone figured that a curve tracer was great for telling if a net had its source, load, and resistive termination. Any part of the characteristic curve missing indicated a bad connection.

The big Tek curve tracers were spendy for this and 99% of the functionality was not needed. One of the engineers whipped togeter a little box with an AC transformer, a pot and a resistor or two. Connected to the X-Y inputs of a scope you had all you needed. The I input on the Y axis of the scope was backwards with the simple configuration, but who cares. Good enough for our needs and cheap.

I made one and use it from time to time for looking at what is connected to a net. Many technologies don't have opposite polarity diode signatures on the source and load like the ECL did, but it can still be helpful, as Gerhard mentions.

yeah, but the Tek curve tracer is really handy. It has so far prevented my bench from floating away (and has scared off all of the elephants, too)

Cheers Terry

spectrum

*curve

Tektronix

ROFL. In fact, they are not that big/heavy. I mean, not the 575. And how do you get that 1.6kV/100W collector power from your laptop/USB CT combo? And how long does it take Tek CTs (no pun) to boot? How often do you have to reboot them? I guess mine has scared off all the mices as well.

--
Thanks,
Fred.

Terry Given wrote in news:1151903923.721333@ftpsrv1:

The TEK 7CT11 fits in a 7000 series scope mainframe,and is a nice little curve tracer. Then there's the Sony/Tek CTs that are smaller than the old

575/576/577 models.I can't recall all their model numbers,though. 370 was one,but there was one model that was a compact CT,not bigger than a desktop PC.the 370 had a microprocessor and a floppy drive for data storage.(might have been for configs,not stored test data)

--
Jim Yanik
jyanik
at
kua.net

I've bought them surplus for under $5 each. You just have to keep your eyes open. The best deal so far was well under $1 each for a batch at an auction.

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Michael A. Terrell
Central Florida

O happy day, you have rediscovered the octopus tester. Please see google. See also "

". How about you find the original name for the device.

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Joel,

Thanks for mentioning the Curve Tracer. I'm glad that you think that it looks useful-enough. And thanks for the kind words, in your earlier message in this thread.

At the risk of encouraging you to buy later rather than sooner, I will say that PC/digital interfacing is already on the "to do" list, for the Curve Tracer product.

It will be "a little while", before that is available, though. (I am apparently one of the slowest electronic designers to ever have existed. But (as I might rationalize, to myself), this is a commercial product, as opposed to a personal-use-only one-off. And I have to wear a lot of different hats, to get it from a raw design to a shippable product. So maybe my development speed is reasonable, after all.)

I did just finish a fairly-major re-design, and am now in the process of trying to ship the new version. Among other things, it finally has a nice calibrated base/gate step output, with selectable current or voltage steps, which now also has somewhat more power available (150mA max @ 15v max step). (Note that "More power!", for both the sweep and step outputs, as well as higher voltages, are also already on the "to do" list for a future version.)

The just-completed re-design was originally initiated mainly to make the unit easier to build (and maintain, if that's ever necessary). But, along the way, most of the sub-systems were also redesigned, for better accuracy and precision (some of them with perhaps a bit of overkill, heheh). [Yes, I finally got addicted to Spice.] It's still a bit of a bear to put one together, for me at least. Or maybe I'm just clumsy. And it's all still through-hole, since I wanted to be able to offer it in kit form, also. (It's also almost all (gasp!) analog.) If I don't say "screw it" and go to surface-mount, soon, I'll probably have to make the case larger [or at least the front panel, since the main pcboard now sits just behind, and parallel to, the front panel (so I could use pcb-mount rotary switches, etc, to eliminate a whole lot of discrete wiring)].

BTW, if anyone else has any suggestions about desirable features, etc, I would very-much-appreciate receiving them. I can also be emailed directly, at: tomg at fullnet.com .

By the way, Joel: I saw that you had emailed me, and (I) have been TRYING to read it, and respond. But some emailed me a hundred or more exTREMEly-large emails, a few days ago, making my email system temporarily almost-unusable (even on my ISP's web-based email service, which is ALL I can even TRY to use, for right now), until I can delete more of them, which is VERY-painfully slow, for some reason. If I had known that it would take this long, I would have temporarily (re)opened a yahoo email account, or somesuch. But, I think I should be able to make it usable-enough, soon (I hope), and be able to answer your email.

Thanks again.

Best regards,

Tom

Tom Gootee

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