I have 3 sets of these solar faery lights: http://www.amazon.ca/dp/B00CDC63HW/ref=sr_ph?ie=UTF8&qid=1433398110&sr=1&keywords=fairy+lights
2 of the sets have died after a year (Water got into the "waterproof" case)
Then I realized: How the heck are they driving 100 LEDs off one 1.2V 600mAh battery???
Opening the unit didn't provide much information. 3 resistors, a capacitor and an unmarked 8 pin IC.
Did lots of googling, but didn't find an equivalent circuit. Anyone have any ideas as to how they're doing this amazing feat?
