___            __   _           _   _              _____   _                  __   _          
 |_ _|  _ __    / _| (_)  _ __   (_) | |_    ___    |  ___| (_)  _ __    ___   / _| | |  _   _  
  | |  | '_ \  | |_  | | | '_ \  | | | __|  / _ \   | |_    | | | '__|  / _ \ | |_  | | | | | | 
  | |  | | | | |  _| | | | | | | | | | |_  |  __/   |  _|   | | | |    |  __/ |  _| | | | |_| | 
 |___| |_| |_| |_|   |_| |_| |_| |_|  \__|  \___|   |_|     |_| |_|     \___| |_|   |_|  \__, | 
                                                                                         |___/  

This spiffy little gum stick sized circuit flashes a LED every couple of seconds. Powered by a small solar cell which charges a super capacitor, it can blink for ~36 hours in total darkness when fully charged. Ambient room light during the day seems to be enough to keep it going through out the night. I also have one powered by an AA battery which has been blinking since March of 2015 with no signs of slowing down.

Schematic:

Parts List:

P1 and C1 can be substituted with a 1.5 volt battery if desired.

The blink rate can be changed by varying R2 and/or C2. I suggest experimenting with this circuit on a breadboard to see what you like before making anything permanent.

Images:

Other Blinky Links:

Infini-Flasher:
Still going strong after nearly twenty years, this blinky in part inspired me to make mine.
http://www.kevtris.org/Projects/led/flasher.html
Forever Flasher:
This battery powered flasher circuit is mostly what my flashers were derived from with a few tweaks.
https://www.youtube.com/watch?v=JenPZMHREfg
Pink Floyd's Pulse Album:
This album included a red blinking LED powered by a LM3909 flasher IC.
https://en.wikipedia.org/wiki/Pulse_%28Pink_Floyd_album%29#LED_packaging