Re: Milky Candle Pilot Run... (SOME NEW PHOTOS).
Minjin, yup, you're on the list! /ubbthreads/images/graemlins/smile.gif
Regarding the red LED, I was originally thinking along the lines of having a socket for the LED itself, so the user could choose whichever one they wanted. The downside to the socket is that it makes assembling the boards a little more troublesome, and the socketed connection itself is inherently less reliable than an LED soldered directly into the board. Plus my own testing and that of a few others found that a white LED driven at VERY low levels, provides plenty of light and runs for a LOOOOONG time! /ubbthreads/images/graemlins/ooo.gif The initial pilot run of Milky Candles was running its lowest setting, "nightlight mode," for roughly 1000 hours in regulation using a fresh pair of 123 cells, and the new circuit will run for much longer than even that. Then again, there's no technical reason that the circuit couldn't use pretty much any LED... white, red... even a Luxeon driven at very low levels! /ubbthreads/images/graemlins/naughty.gif
I suppose maybe I could have a certain number of boards available with a red LED rather than white? Or maybe sell the boards themselves for those inclined to tinker? I don't have any sense of how much interest there might be in those options. /ubbthreads/images/graemlins/thinking.gif
Regarding other battery configurations, the new circuit will actually accommodate pretty much any configuration within reason. It'll be a buck switching topology, so the main requirement would be that the voltage supplied exceed Vf of the LED... otherwise the circuit would fall into direct drive. So with a white Nichia, 2x123 works, as would 4AAA, 4AA, 4C, 4D, 6AA, 3x123, 2xCR2, and many more. It's the housing itself that is specifically designed for 2x123.
I'll follow MR Bulk's lead in saying flat out that this 2x123 run will most likely be followed with another iteration of the Milky Candle powered by the same circuit, but in a totally different configuration, heh heh... /ubbthreads/images/graemlins/naughty.gif