Letter Re: Lower Power DC Lighting
James Wesley: I am writing by the light of a post-apocalyptic reading lamp I just constructed. From a string of LED Christmas lights, I removed two sections of just three LEDs each. To each of these I attached in series a single 100 Ohm resistor from the parts bin at Radio Shack. A goose-neck work light provided a good reflector and glare control. I cut the plug off the other end and crimped on the connectors appropriate to my battery. The battery was salvaged from a defunct computer UPS. They are common to alarm systems and are not expensive new. …