LED Beginner Project: Part 2 I've always been looking for a reason to use an Altoids tin as a project box, and this project seemed to be it. - Altoids tin - 2 AAA battery holder from Radioshack. - three way toggle switch that I scavenged.
LED Parts LEDs come in all shapes and sizes, but the 3mm T-1 or 5mm T-1¾ are probably the most common. The die is an itty bitty cube of semiconductor, the composition of which determines the color of the light given off. Notes on LEDs
Running Christmas lights off batteries (DC power) This page was the original hook-up on the web for battery Christmas lights! Way back in the 1990s this page showed readers how to re-wire Christmas lights to run off batteries, since battery-powered Xmas lights were extremely rare. The article also turned readers on to LED Xmas lights, which were new and extremely rare at the time. Battery Christmas Lights: How to convert Xmas lights to run on batteries/DC (regular or LED)
One of the bummers of Christmas is trying to get the strings of lights to work. The biggest culprit are the strings that are connected in series. These are usually the strings of so-called miniature Christmas lights with the push-in bulbs. LED Christmas lights
Most recent update or addition in anything below of mine 11/30/2013, with the latest noted update on links offsite from here 12/25/2013. Efficient and bright LEDs! Efficiency of some good ones and some runner-ups in lumens per watt, millicandela and beam angle ratings for some of these, where to get most of these. Don's LED Main Page
Alan Parekh's Electronic Projects - LED Resistor Calculator