Originally Posted by ajg141

Came across an article on the internet telling you how to make a sub buoy from balsa, a 5-volt flashing LED attached to a 1.5K ohm resistor, various springs and washers plus a battery. As I don't know the first thing about electronics can anyone tell me what voltage the battery should be? I did ask the store where I bought the LEDs but they were a bit bemused and wondered why a resistor should be necessary at all. Any help would be appreciated.

Andrew