I know there are experts out there designing / building curve tracers.
This uC based kit has been released recently by Prof. Dr. Ronald Dekker (Philips Research Laboratories, Eindhoven und Delft University of Technology). <impressive title ...>
The uTracer, a miniature Tube Curve Tracer / Tester.
Would be interesting to get some comments from people with experience in this field ...
This uC based kit has been released recently by Prof. Dr. Ronald Dekker (Philips Research Laboratories, Eindhoven und Delft University of Technology). <impressive title ...>
The uTracer, a miniature Tube Curve Tracer / Tester.
Would be interesting to get some comments from people with experience in this field ...
Brilliant!
I may need one.
It has one shortcoming, the voltage limit is 300v.
So this means that it is somewhat limited as to what it can test at full voltage. (there must be a way to get that voltage limit closer to 500vdc).
But for small tubes and things up to about a 6V6 it would be hard to beat, imo. Just looking at the pages that is, I have no experience with his unit or the measurement method (pulsed DC).
_-_-bear
I may need one.
It has one shortcoming, the voltage limit is 300v.
So this means that it is somewhat limited as to what it can test at full voltage. (there must be a way to get that voltage limit closer to 500vdc).
But for small tubes and things up to about a 6V6 it would be hard to beat, imo. Just looking at the pages that is, I have no experience with his unit or the measurement method (pulsed DC).
_-_-bear
Disclaimer : I'm not an expert in this field. I've built a curve tracer based on the LampMeter which is sold on ebay. I've also done a theoretical design of a curvetracer and built breadboards of each section to verify them, but never finished a complete curve tracer based on it. Others have used the basic design and made modifications to it resulting in completed curve tracers.
In addition to what bear said, the pulsed DC method has a limitation in driving heavy capacitive loads, so some big Triodes may pose a problem.
The pulse method has the advantage in that device dissipation limits can be exceeded because the average power dissipation is kept within a SOA, so the tube can be tested beyond static limitations.
I read a lot on his site back when it was at V2.0, and thought then that the tester seems to be thoroughly thought out and well implemented.
The software GUI is going to be a major factor in usability.
In addition to what bear said, the pulsed DC method has a limitation in driving heavy capacitive loads, so some big Triodes may pose a problem.
The pulse method has the advantage in that device dissipation limits can be exceeded because the average power dissipation is kept within a SOA, so the tube can be tested beyond static limitations.
I read a lot on his site back when it was at V2.0, and thought then that the tester seems to be thoroughly thought out and well implemented.
The software GUI is going to be a major factor in usability.
I must say that the concept is quite unique and well thought out. I have been contemplating a tube tracer using conventional power supply and current measurement techniques. I never got around to building it, since the actual circuit design is the easy part. The software and GUI design isn't.
I don't think it would be too hard to get past the 300 volt barrier either. You would need something bigger than a laptop power supply though.
I don't think it would be too hard to get past the 300 volt barrier either. You would need something bigger than a laptop power supply though.
The GUI is something that I did not look at yet.
One comment on his site is that there is presently no way to store "macros" that represent settings.
It's unknown to me if one can store results (curves) and/or overlay them.
These two things are important.
It's possible if the code is open, since it is visual basic, that one might be able to write one's own functions to do this, but I'm not much of a programmer, and it would be better to have this stuff as part of the package.
As far as the 300v barrier, I didn't quite grasp what the limit was in the circuit. Using something other than a laptop supply isn't much an issue from where I sit. In fact for most of us making up a linear supply from junkbox parts is a "no-brainer"... the size of the unit isn't much of an issue for lab use.
_-_-bear
One comment on his site is that there is presently no way to store "macros" that represent settings.
It's unknown to me if one can store results (curves) and/or overlay them.
These two things are important.
It's possible if the code is open, since it is visual basic, that one might be able to write one's own functions to do this, but I'm not much of a programmer, and it would be better to have this stuff as part of the package.
As far as the 300v barrier, I didn't quite grasp what the limit was in the circuit. Using something other than a laptop supply isn't much an issue from where I sit. In fact for most of us making up a linear supply from junkbox parts is a "no-brainer"... the size of the unit isn't much of an issue for lab use.
_-_-bear
I didn't see any mention of source code availability, nor any place to download it. This means you are at the mercy of the original programmer for updates or feature changes.
The hardware, including the power supplies are very simple, but require software to operate. Changing a power supply voltage from 300 to say 500 volts would require hardware AND software changes.
Dr. Dekker's site is a good read, lots of good info there. As for the uTracer, the 300V plate limit and non-availability of the source code have prevented me from ordering/building one. Dr. Dekker does sell the PIC with the code on it for a very reasonable price of EUR20, but you cannot modify the code or change the UI...
The best UI I have seen so far is Yves' TCT, unfortunately, he no longer works on the program/project and very few people (I think) ever got it to work on their own PC (I kept getting VB runtime errors).
Jaz
The best UI I have seen so far is Yves' TCT, unfortunately, he no longer works on the program/project and very few people (I think) ever got it to work on their own PC (I kept getting VB runtime errors).
Jaz
For the price you can't get anything else like it...
I was thinking about starting up a "Group Design DIY Tube Curve Tracer" thread... not sure there is enough interest, although I suspect there is expertise.
The balancing point would be between a stand alone scope accessory, analog type and a PC or Arduino type controlled digital I/O w/GUI + analog drive circuitry.
My personal situation dictates that my time is limited to these daily but short posts to DIY and I can't even spend time on my own projects. 🙁
But I think this might be a project that the group could take on and bring to fruition?
IF it were designed as modules, it might be possible to provide it in several flavors. For example the anode supply could be standard linear, off-the-shelf SMPS, or DIY SMPS... etc.
_-_-bear
I was thinking about starting up a "Group Design DIY Tube Curve Tracer" thread... not sure there is enough interest, although I suspect there is expertise.
The balancing point would be between a stand alone scope accessory, analog type and a PC or Arduino type controlled digital I/O w/GUI + analog drive circuitry.
My personal situation dictates that my time is limited to these daily but short posts to DIY and I can't even spend time on my own projects. 🙁
But I think this might be a project that the group could take on and bring to fruition?
IF it were designed as modules, it might be possible to provide it in several flavors. For example the anode supply could be standard linear, off-the-shelf SMPS, or DIY SMPS... etc.
_-_-bear
Actually there is an effort going on already:
http://www.diyaudio.com/forums/tubes-valves/206787-micro-programmable-tube-tracer-tester.html
http://www.diyaudio.com/forums/tubes-valves/206787-micro-programmable-tube-tracer-tester.html
yeah, read that with high hopes - seems like it has stalled out after a very good start... too bad it wasn't "open source". 🙁
Nobody can even try to pick up where it left off... 🙁
Oh well...
_-_-bear
Nobody can even try to pick up where it left off... 🙁
Oh well...
_-_-bear
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