Ring Oscillator Blinkenlights

Burkard Kainka, one of favourite my electronics Muses posted a video on YouTube and his site of a 9-stage ring oscillator LED "das blinkenlight"-style project. I think most of us have built something similar, especially 3-stage ones for fun, but the simplicity of the circuit and the question of its behaviour with different numbers of stages was very inspiring. Naturally I threw some together myself, building 5 and 7 stage versions to confirm they worked as expected and posted some footage on YouTube:

Rather unexpectedly, this started quite a bit of talk on Twitter about how they actually work and what one might do with them... Mark did some software simulations in LTSpice and by hand, Dave built an unusual (and interesting) series relaxation oscillating topology that I am yet to try myself and Alan Garfield built the minimal 3-stage version.

A few days passed as I toyed with software modelling of the circuit and hardware cellular automata ideas which it had rekindled interest in before I finally built a 37 stage version to observe its behaviour at large numbers of stages and try some ideas I had about branched and recirculating topologies.

Interesting how something so simple can offer such a variety of experimental interest. Also, this minor flurry of activity shows the power of social networking. I find Twitter both a fascinating anthropological laboratory and useful communication device capable of inspiring amazing collaborative exercises in a range of different disciplines. That 140 character "limit" is not at all as limiting as it might at first appear, the mandatory brevity (something I clearly struggle with!) encourages dense coding and rapid communications, and enables linking to more verbose descriptions when required.

Leave a comment on this article.