Looks like those limitations may be addressed soon -
from http://www.circuit-ed.com/forums/viewtopic.php?t=80
"We will be offering a new release of the PC software soon. It will have some advanced features such as being able to select the start and stop Gate/Base values and number of tests to do between those values. It will also have some default selections that will help provide basic user control over the test."
from http://www.circuit-ed.com/forums/viewtopic.php?t=80
"We will be offering a new release of the PC software soon. It will have some advanced features such as being able to select the start and stop Gate/Base values and number of tests to do between those values. It will also have some default selections that will help provide basic user control over the test."
I sent them an email and got a response back in a couple of hours:
Hi,
It's good to know that our home-grown product has received such attention. We recently released the board and provided user instructions but failed to provide voltage/current specs. We will be posting that information soon.
This tester is totally USB powered and therefore has some limits. The maximum collector/drain current is presently 22ma. We have a next generation board in the works with more features and greater capability, but it may be a couple months or so from production. In the meantime, we have realized a relatively simple board hack for the CT100 that can provide increased capabilities to 44ma, and possibly over 80ma. We are doing tests to confirm our expectations and then let our customers know how to do it. We will provide the software that manages the increased testing and graphing parameters as a free download.
Hope this helps.
Regards,
Warren Schroeder
CircuitED
Hi,
It's good to know that our home-grown product has received such attention. We recently released the board and provided user instructions but failed to provide voltage/current specs. We will be posting that information soon.
This tester is totally USB powered and therefore has some limits. The maximum collector/drain current is presently 22ma. We have a next generation board in the works with more features and greater capability, but it may be a couple months or so from production. In the meantime, we have realized a relatively simple board hack for the CT100 that can provide increased capabilities to 44ma, and possibly over 80ma. We are doing tests to confirm our expectations and then let our customers know how to do it. We will provide the software that manages the increased testing and graphing parameters as a free download.
Hope this helps.
Regards,
Warren Schroeder
CircuitED
"Zero Cool" was good enough to let us know that there has been some discussion about our CT100 Semiconductor Curve Tracer. If anyone has questions please feel free to contact us about the product.
The CT100 came into existence for many of the same reasons expressed here in this DIY forum. We originally needed to find an economical method of testing FET's for matched characteristics for a customer who produces high-end audio tube amplifiers, and so we came up with a nice board to do the job. We decided to try the market and the response has been excellent. We will soon release more flexible testing software and will be improving the overall dynamic testing capabilities of the board. All software upgrades and downloads are free.
In order to improve the function and appeal of the product we are always open to suggestions for improvement.
The CT100 came into existence for many of the same reasons expressed here in this DIY forum. We originally needed to find an economical method of testing FET's for matched characteristics for a customer who produces high-end audio tube amplifiers, and so we came up with a nice board to do the job. We decided to try the market and the response has been excellent. We will soon release more flexible testing software and will be improving the overall dynamic testing capabilities of the board. All software upgrades and downloads are free.
In order to improve the function and appeal of the product we are always open to suggestions for improvement.
wds said:
since you asked...
1) add a provision for an optional external supply to support testing at higher currents
2) keep the price where it is
3) maybe start a new thread asking for input - I'm sure you'll get an earful
4) send me a complimentary unit for bringing it to the attention of diyAudio
Seeing as you asked.
I would like to see a full featured version of this. something with software that would allow full control. I would also like to be able to test at currents up to 10 amps.
I would like to be able to specify what currents the unit is to test at. IE, 0, 1ma, 10ma, 100ma and 1000ma etc.
I want to be able to input a specific test current for a single shot curve. IE: be able to input some specific current level like 63ma or 144ma as the test current and not just some mulitple of 10. This could be a software driven thing where the device tests at two current levels above and below the specified current and extrapolates the data.
I want to be able to set up go/no go parameters in the software so that i can quickly run through a batch of devices and identify devices in range.
I want to be able to label and store curves and have a way to export the data in some format such as an text document or excell spread sheet.
Auto store function so that an operator could insert a device. press a button and the box traces the curve and then stores the trace.
This button function should also be available on a rear control port. or available through the PC's serial or printer ports.
This would allow your box to be incorporated into automated testing stations during manufacturing operations.
Automatic detection of device such as NPN or PNP or direction of diode.
Looking ahead to the future. Optional expansion boxes would be cool.
A Multiplexing box that would allow multiple devices to be connected with automated testing. IE: be able to connect 10 devices at once and have the box test and automatically store curves for all 10.
This multiplexing system should allow more then one set of mult cables to be connected at a time with hotplug and A-B test capability. an operator could load up one set of devices, start toe unit, then load up the next set of devices, once the first are done, then the operator could remove them and reload them and continue.
Various test fixtures for specific types of devices that plug in to the main unit.
A full stand alone unit with LCD screen and USB capabilities would be cool.
Optional printer port for the stand alone unit.
I would like to see a full featured version of this. something with software that would allow full control. I would also like to be able to test at currents up to 10 amps.
I would like to be able to specify what currents the unit is to test at. IE, 0, 1ma, 10ma, 100ma and 1000ma etc.
I want to be able to input a specific test current for a single shot curve. IE: be able to input some specific current level like 63ma or 144ma as the test current and not just some mulitple of 10. This could be a software driven thing where the device tests at two current levels above and below the specified current and extrapolates the data.
I want to be able to set up go/no go parameters in the software so that i can quickly run through a batch of devices and identify devices in range.
I want to be able to label and store curves and have a way to export the data in some format such as an text document or excell spread sheet.
Auto store function so that an operator could insert a device. press a button and the box traces the curve and then stores the trace.
This button function should also be available on a rear control port. or available through the PC's serial or printer ports.
This would allow your box to be incorporated into automated testing stations during manufacturing operations.
Automatic detection of device such as NPN or PNP or direction of diode.
Looking ahead to the future. Optional expansion boxes would be cool.
A Multiplexing box that would allow multiple devices to be connected with automated testing. IE: be able to connect 10 devices at once and have the box test and automatically store curves for all 10.
This multiplexing system should allow more then one set of mult cables to be connected at a time with hotplug and A-B test capability. an operator could load up one set of devices, start toe unit, then load up the next set of devices, once the first are done, then the operator could remove them and reload them and continue.
Various test fixtures for specific types of devices that plug in to the main unit.
A full stand alone unit with LCD screen and USB capabilities would be cool.
Optional printer port for the stand alone unit.
Zero Cool said:
This will no doubt be part of the evolution of the software, and within the limits of the USB power supply and our electronics wizardry.
Ditto!
A text report was in our first prototypes but was later removed. We will consider re-inserting this feature. You can presently save the graph as a BMP.
We consider simplicity a feature and not necessarily a liability. Our intent is to design something useful for many, but not all users. And again, you never know.....demand may drive us to do some interesting things.
The stand alone idea if something we are very interested in doing.
ANTHONY2181 said:
I was curious about that telequipment box but i couldnt find any specs on it. and there are several Tek 577's on ebay for about $100
At this point i think i am going to wait a bit and hope that Circuit Ed comes out with Rev 2 of there USB box quickly. That is unless i find a really stupid cheap deal on a Tek or something.
Both Hagerman & Transcendent have curve tracers -- each is a bit different.
http://www.transcendentsound.com/tube_analyzer.htm
http://www.hagtech.com/vacutrace.html
Having something that interfaces with a computer & slick software could be way more powerful.
dave
http://www.transcendentsound.com/tube_analyzer.htm
An externally hosted image should be here but it was not working when we last tested it.
http://www.hagtech.com/vacutrace.html
Having something that interfaces with a computer & slick software could be way more powerful.
dave
Here's a question for semiconductor curve tracer users. When comparing and matching multiple devices, what comparisons are you most focused on, or what part of the curves are you trying to most closely match? At what point do you select a device as the model to work from and then decide when another device is matched?
Whew! Those are tough questions to frame properly.
Whew! Those are tough questions to frame properly.
wds said:
This is probably best answered by someone else as i am new to this subject myself. Good question. I am very curious now to know the answer myself.
But, from asking questions around here. What i have learned about matching in general is that i need to look at the Vbe as well as the Hfe for a device and then match devices within a certain % of each other. Sometimes the Vbe is more important then the Hfe. and matching both is ideal if you have a large lot of devices to choose from.
Apparantly, at least for output devices, that matching devices to each other is less important then finding a specific gain number.
So, What it sounds like a person needs to do, is test the entire lot of devices you have to choose from. then group devices into lots of devices close to one another. then select devices from the middle of the lot or as close as you can get with the number of devices needed.
From my limited testing of devices with my little M3 brand tester. I noticed when testing a lot of 25 devices that many were grouped around a particular Hfe and that there were extremes either way. those devices i rejected and kept the devices that were close together in the middle of the range.
Now, from reading some info from Nelson Pass about IR brand Mosfets. apparantly the P channel IRF brand devices exhibit something strange in there curve when compared to say Harris Brand of the exact same device. Neslon noted that he has not noticed a difference in sound. but now that is something you would not have ever seen without a curve tracer. Im sorry i cant remember the exact place i read that. or exactly what the issue was. but that is the jist of it.
Does any of that help??? It would be better Hearing from people that are way more in the know then i am. One lf the reasons i want a curve tracer is to learn.
Zc
P.S. Shamless Plug. But if anyone here is into building things with PIC Mcu's. Circuit-Ed has some very cool PIC development boards. Now that the EasyPic4 just came out. i am saving my pennies and there is one in my near future!
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