Just a little update, I've tried regular neon indicator bulbs (most of them start conduction at around 75V) and only one showed oscillations and only at low max current ratings.
Here're a few pictures of the V/I traces of regular small lamps. Tilted traces are lamps with internal resistor, so the resistor is tilting the trace. Frank
The one that oscillated (IMG_1950.JPG) looks very much like your original video. It would be helpful if you increased both the vertical and horizontal gain of your photos so some detail could be seen:
If you happen to have a few identical NE-2 lamps, put three in series to get something close to the 200v as in the gas discharge tube. Then, compare the displays.
Also, smaller JPG's please. This test does not require 12 megapixel images.
that's the max vertical "gain" that I can have on the IT-3121, 0.5mA/div.
I've just tried that, no oscillations.
Sorry for that, I've not plaied with the camera settings.
Here's a video of the oscillating neon lamp, the higher current is obtained with 100k resistor, the lower current (and larger oscillations) is with
500k limiting resistor:Have something to add? Share your thoughts — no account required.
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