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.
I built a characteristic tester - all details here
A set of data readings is exported as a .csv file that you can easily display in excel or libre office chart
I'd be concerned about the "simple" hackaday circuit - it can put 18V pk-pk AC across the component, with no current limit; also there is no calibration so the "measurements" have no meaning.
We had something like that in the workshop I used to work in. When I first saw it I thought it was a stupid idea, turned out to be one of the most useful pieces of test equipment I have ever used. Didn't need comparison traces, the difference between a good and a faulty component was obvious.
Following the formula of the video (Normalized Correlation), I believe that the result of comparison is interesting, my next step is to try to do it with a microcontroller to find out if it will have resources.
Note: After calculating the correlation for each axis, I multiplied the result of the axes and inverted the result, to show the difference. If this is not correct, please comment on any suggestions. (These data in the calculation spreadsheet are not the same as in the image above).
Explanation:
Normalized cross-correlation is also the comparison of two time series, but using a different scoring result. Instead of simple cross-correlation, it can compare metrics with different value ranges.
johnerrington:
I built a characteristic tester - all details here
A set of data readings is exported as a .csv file that you can easily display in excel or libre office chart
I'd be concerned about the "simple" hackaday circuit - it can put 18V pk-pk AC across the component, with no current limit; also there is no calibration so the "measurements" have no meaning.
PerryBebbington:
We had something like that in the workshop I used to work in. When I first saw it I thought it was a stupid idea, turned out to be one of the most useful pieces of test equipment I have ever used. Didn't need comparison traces, the difference between a good and a faulty component was obvious.
Yes, the differences are generally clear, but sometimes they are smoother, in addition, if it is possible to compare, it is possible to automate the verification, and mainly to define at the end of the test whether or not it passed the test.
