What is it good for?
It is good for compare a working and a not working circuit board, without you have to apply any power to it. A curve tracer show Voltage - Current characteristic of any electric component, like diodes, capacitors, CMOS ICs and many more, which you want to look.
This equipment mostly used in repair purposes
I created two version of the tracker, called Version 1 and Version 2. Recently I am working on a new version (Version 3). Below this lets see how each version works.
I started develop this version about a year ago, when I saw a Huntron tracker at my work and I thought it is not too difficult electronic, but so overprice at the same time.
The Version 1 has just one voltage and one frequency range, so it is a very basic model. The basic idea behind a curve tracer a simple circuit, which input is a sine wave and has some resistor in it. We need a current limit resistor and a current sense resistor.
The other big part is a dual channel oscilloscope with X-Y mode, or like my version I used a cheap arduino pro mini and a display, it is more then enough for a basic operation. I added a function, with the tracker can save a curve on the display and can measure an other component at the same time, so with that you can compare a good component with a bad component.
The sematic is a updated version, with some compensation, and modification on it, I could reduce the short circuit difference, so the line is almost vertical on the screen, when the two probe is shorted.
The upper op-amp is the voltage sense (X axis on the screen), the lower op-amp is sensing the current, which is flowing through the measured component (Y axis on the screen).
Some picture about the Version 1
It is not too pretty, but it works well, for a beginner I recommend to start with this, because it is cheap, and after easier to improve.
A short slow mo video how it is works.
I am planning to add some feature to this version, so it more capable of repair works.
The second version is basically a much closer producte what I really wanted to create, it is based on the Version 1, but I learned a lot from my mistakes. I wanted a multi range and pc compatible version with the stand alone usability without pc, so most if the time I can use it like a independent device, but if I have to I can sove the curves to the pc as well. The development was long, it took me more than half a year, and a lot of money as well. I think it is worth all the time I put in it.
Lets start show what I am talking about.
It has 25 voltage range, 5 resistance and 6 frequancy range. The screen is a 4" mcufriends tft touch screen, but in this operation I did not put any function on the touch screen. The Version 2 has two channel, it is more easier to compare curves at the same time.
The buttons light up when the actual function selected.
This device is much more complicated then the first version was, so I do not recommand a beginner to try to build this. I am planning on making a kit about every version, so it will still stay cheap and I can give a little bit of fun to build these.
The Version development is still on progress, so I did not have a propper schematic, but it will be released soon, as well as the code.
More info about this version you can find below at the log section.
I started developing a new version at a couple weeks ago, which will be similar to the Tektronix TR210. It is basically the Version 2 without the screen and any pc connection option. For this version you need a dual channel oscilloscope, but I think it is not a proplem for that who is looking these types of instruments. I would like to make this open source, like the Version 1 so if anybody want to help developing this version, please contact me.
Version 3 will have at least 25 voltage range, 5 resistance and minimum 5 frequancy range, and ass well two channel measuring input, with alternating mode.
I designed the scheamtic, it is not done yet, but close to it.
You can find the documentation at...Read more »