So the other day I was chatting with @Kluper. She wanted to create a 'learn to solder' board for the coming open house in Kicad. I mentioned that i had created a basic SMD board with the idea that @artg_dms could teach some learn to solder smd classes. So I sent her the Kicad files with the idea that all she needed for a through hole solder board was to switch the footprints on the parts (jelly bean transistors (3906), four resistors, two caps, two LEDS, and a battery holder.
This circuit is a wonderful one, I first came across from Forest M. Mims book many, many years ago. I am thinking about creating a class where we look in detail at how this circuit works. I think I will call itm "You don't need an Arduino to Blink and LED" And perhaps with a little encouragement, we can get @artg_dms to teach that class on SMD soldering.
Anyway, I finally got around to assembling one of the three boards from my initial order with OSHPark. It took some time, but I finally caught a photo of D1 (led on left) as it was extinguishing as D2 (led on right) was approaching full brightness. This circuit is known as a multivibrator (or flip-flop) and the two leds flash opposite of each other.