In this flashing led lights circuit, the LDR or photoresistor is connected in such way that when the light intensity varies it will influence the flashing. ... The whole flashing led circuit is ...

It’s a project called snapVCC, and it turns a 9 volt battery into a regulated 3.3 or 5 volt supply. The idea behind snapVCC is simple enough; just add a circuit board to the top of a nine volt ...

The whole circuit, complete with tiny speaker and an LED to indicate pulses, sits neatly on top of a 9-volt battery. The video below shows it in action with a test source.