I recently put together a set of moonlights using a 9v dc
power supply and 3 LEDs from lsdiodes.com. Also, I used the calculator from http://metku.net/index.html?sect=vie...calc/index_eng
this site which said I should use one single 91 ohm resistor. The lights all look great and each has 3.3v across. However, the resistor gets very hot after just a few seconds. Is this normal? Will it cause problems if it is plugged in for any length of time? Here is a wiring diagram. If I were to use 3 separate resistors, what size should they be if I wanted 3.5v across at 20 ma?