Curve Tracer or Audio Analyser?

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#22
Jazid said:
Negative grid down as far as you can manage...Although the majority of audio tubes seem to need modest grid volts, 300b like - 75V at average operating conditions, and transmitting valves can take some *different* conditions. So saying - 120V sounds good?
I guess for us tinkering DIYers there's also a joy in old valves, and these can definitely use a tracer. Even identifying some 1920s/1930s valves might be easier with a tracer! For me at least [emoji16]
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See what we can do. There's not alot of difference from -75V to -120V, so the topology should easily extend down that far.
 
#23
thermionic said:
NB - the key phrase is 'given the R+D budget'. I'm guessing there is a reason why R+S haven't released a successor to the UPV in 15 years. They will have far more profitable cash cows in the RF world.
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If the demand was there, I'm sure R+S would have updated the UPV by now - as you say, RF is much more profitable. It's only this year that Keysight have replaced the 3458A 8.5digit multimeter - they were forced to due to RoHS; and that design was largely unchanged since the late 80's. They replaced it with a virtually identical unit called the.. 3458A
 
#24
An update as now finalising board layout for pre-production unit.

The grid will reach -200V and is fairly stiff at that. We've ended up with 6 channels of simultaneous conversion at high resolution: anodeV/I, screen V/I, grid V/I + heater voltage/current measurement (12bit) or in semiconductor mode: collector V/I and base V/I.

The fully floating 0-400V supplies are pretty stiff, have current limiting and can be stacked for 800V testing on something like a 300B. Unit has relay switchable outputs for A/B testing and an interface on the back for a switching box if called for in the future.

It's been really good fun to spend time with glowing bottles again. Love to hear from tube/valve officinados with curve-tracer experience in UK/EU for testing/comments. We did look at doing this whole thing as a kit, but decided against it as we aren't setup for kitting and there is a lot of surface-mount.
 
#25
I might be a bit late to the party...

There are good and affordable modern tube curve tracers available. I have an etracer, which works well and didn't cost an arm and a leg. In my view it does not make too much sense to invest a lot in developing yet another tube curve tracer (except maybe if it's just a small effort to expand an already existing design).

Curve tracers for power transistors seem to be a different story. When I was looking for one a few months ago, I couldn't find anything with a computer interface and suitable software, neither as a finished product or in kit form. It would be cool if you could fill this gap!
 
#26
mbrennwa said:
I might be a bit late to the party...

There are good and affordable modern tube curve tracers available. I have an etracer, which works well and didn't cost an arm and a leg. In my view it does not make too much sense to invest a lot in developing yet another tube curve tracer (except maybe if it's just a small effort to expand an already existing design).


Curve tracers for power transistors seem to be a different story. When I was looking for one a few months ago, I couldn't find anything with a computer interface and suitable software, neither as a finished product or in kit form. It would be cool if you could fill this gap!
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The Curve Tracer project originated sometime back, it started life when I needed to test high-power LED's for a clients design I was doing. This then morphed into transistor testing before the project was shelved. As per the beginnings of this thread I wanted to revive a couple of these projects for my company (Electron Plus).

Alot of the electronic design and firmware was done for the CT as well as the framework for the PC side of things. But as the market is probably small for either an affordable semiconductor or tube curve tracer it seems logical to build one that could do both. The CT is designed so we can build a few different variants (i.e. a semiconductor only version) to better match the user.

I've had a look at both the utracer and etracer units. We are likely to be competetive with etracer for our production CT (fully-loaded), with the semiconductor CT being quite a bit less.
 
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#27
Thinking a little more about this, to me frankly exciting, project I imagine that if you could find a way to allow the user to define the operating conditions of the semiconductor/valve under test and thus allow selection according to use, you must end up with something with a greater market place? Either way, keep it coming [emoji115]
 
#29
Hi,

I assume he means that the thing is designed modular, so that You can connect a controller module to different hardware modules.
Those hardware modules could be for example a low voltage low current small signal transistor module, or a high-voltage low current tube module, or a mid-high voltage high current audio power transistor module, or a very high voltage medium current audio power tubes module.
The famous Tek 576/577 already had optionally (pulsed) high-current extension modules.
As far as I can see modern commercial devices like Keysights 5000 are still made in a almost free configurable, scalable fashion.
A modular concept would also allow for different technologies, starting from a simple transformer-generated Anode supply like used in the old TEKs up to using up to four SMUs like in the modern Keysight.

jauu
Calvin
 
#30
benc said:
I'm now a full-time instrument maker
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Best of luck with your business.

benc said:
Curve Tracer
PC connected
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Can we get Mac support too?

benc said:
Audio Analyser
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If you develop an audio analyzer, you need to beat the performance/price of a sound card or the Quant Asylum QA401. One possible compete would be to write better software. I'm guessing you're not taking on AP in the hardware department... 🙂

Tom
 
#32
Calvin said:
Hi,

I assume he means that the thing is designed modular, so that You can connect a controller module to different hardware modules.
Those hardware modules could be for example a low voltage low current small signal transistor module, or a high-voltage low current tube module, or a mid-high voltage high current audio power transistor module, or a very high voltage medium current audio power tubes module.
The famous Tek 576/577 already had optionally (pulsed) high-current extension modules.
As far as I can see modern commercial devices like Keysights 5000 are still made in a almost free configurable, scalable fashion.
A modular concept would also allow for different technologies, starting from a simple transformer-generated Anode supply like used in the old TEKs up to using up to four SMUs like in the modern Keysight.

jauu
Calvin
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Thanks for your feedback Calvin and others. I looked at modularity, the cost to build it fully modular would be make the unit more considerably more expensive.

Technology is from our SMUSB project so we have great low voltage/low current ability as well as high voltage/high current functions from the previous CT project (and the permutations in between).

I'm trying to avoid mission creep and stay focused on building a USB connected CT for small semiconductors, power semiconductors and tubes/valves used in audio. Perhaps there is a market outside audio which will help offset development costs but I suspect it's limited. Building a SMU is not easy (I know!), building a SMU like the ones fitted to a Keysight B15xx or Keithley SCS is moonshot stuff.
 
#33
tomchr said:
Best of luck with your business.


Can we get Mac support too?



If you develop an audio analyzer, you need to beat the performance/price of a sound card or the Quant Asylum QA401. One possible compete would be to write better software. I'm guessing you're not taking on AP in the hardware department... 🙂

Tom
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Hi Tom,

MAC support. Yes - there is a switch in the compiler to generate MAC and Linux versions, and I've been careful to only write EPIC (our control software) with functions that are compatible with all three OS types. That said, I haven't tried it, but will soon. It's on the roadmap to build in scripting of some description.

With due respect to Quant Asylum, it's not super difficult to beat their performance; they make a great product for the money. It'll be interesting to see where they go from here, I suspect upmarket. After looking carefully at whats on offer now (compared to 2011 when I built my first AA) there seems to be enough low-mid range AA's. I would only be excited to go toe-toe with the best that AP has to offer - this would be a MAJOR undertaking here and beyond our resources at present, although I have some ideas.
 
#39
Mark Tillotson said:
Also another vote for mbrennwa's suggestion re scriptability / Python library/wrapper
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A Python library / wrapper would be nice. However, not everyone uses / likes Python. The first priority would therefore be on the full documentaion of the computer interface. For example:

Serial / COM port via FTDI USB adapter, 9600 baud (or whatever)
Command syntax to set current and voltage values to the different pins
Command syntax to read current and voltage values at the pins
Command syntax to set current / voltage ranges (micro amps, milliamps, amps, etc.)
...

Based on this, it would be possible to build a Python (or whatever) wrapper that would make it easy to set up custom programs / scripts.
 
#40
Hi,

we don´t even know the block schematics yet and you start thinking about the end of the rope? 🙄
Measurement devices don´t ineviteably require computers, scripts etc .... its just an add on for convinience.
I suggest we concentrate on defining a concept and the important building blocks first. 😉

jauuu
Calvin

oh, bztw. I´d like it to have voice recognition instead of weird ´snake stuff´ 😛
 
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