Watching a single LED blink is potentially hypnotizing, even if it blinks at a fixed rate with a fixed duty cycle. That’s promising for a set of three LEDs flashing in quasi random order with a constantly varying duty cycle. An out-of-body experience? Nirvana? Kobain? Maybe you just fall asleep. Anyway, the simple circuit presented in this .POST article will flash three LEDs in such a way that you can look at them for hours without ever getting bored.
 
Don't miss any project, take out a free membership to Elektor.POST now!

The sun always shines on TV, and circuits always work on paper! Unfortunately, in reality that’s not always the case. Knowledge and experience help when it comes to solve problems in the real world, and sometimes, as we will see, we can even exploit such issues to our advantage. For example, the circuit presented here doesn’t really behave as it should in (naive) theory.