Spice model creation from measured voltage current graph for selenium diode

Hi, is there a way to derive a spice model definition for a device (a single-cell selenium diode) on which I measured the voltage versus current graph ?
In attachment the data noted in an Excel sheet, including the corresponding graph.
Measurement 0,7 St10 diode from Transita49m.xlsx (14.7 KB)

When I create a small test circuit like described in Device Reference Guide by KSKelvin.pdf , page 38, and try various models from Bordodynov’s diode list, I still cannot find any type coming close enough …

Is this what you are looking for?
I use Diode Model Generator for this task. In Qspice, File > Model Generator > Diode. There is instruction in “Help Docs” in Model Generator.

Single-cell Selenium Diode.qsch (1.5 KB)

Creating a SPICE model from scratch based on some measured data can be tricky, and I mean really tricky. Very tricky. like Selenium diode tricky. The generic models just don’t cut it sometimes. I’ve not had much success with custom equations when I have tried to extract them from data using a curve fitting tool. This is better than preset models, especially when QSPICE has those options for that (i.e. non-linear devices more accurately.)

Thanks KSK, as the selenium diode is used in an audio amplification section, this model is superb ! And thanks again for your documentation and support.
Paul

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