To make a long story short, Im having trouble helping my son with his science fair project. We decided to look at the relationship between resistance and the life of an LED. I wired 8 LEDs in parallel (theres no significance to the number 8, its just the number of LEDs I had in the box that were all 1.9V and 20mA) with 8 different resistors (0, 1, 10, 33, 82, 220, 510 and 1K ohms). Im using a DC power source thats putting out 14.6V. I figured I could wire the LEDs in parallel and avoid having to provide 8 separate power supplies. I expected the 4 LEDs below 82 ohms to burn out and the other 4 to continue to be lit for the duration of the experiment. However, when I built the circuit, none of the LEDs light at all. I suspect I'm missing something basic and any help or ideas would be greatly appreciated.