I have a small project that I've wanted to build for a while but I'm not quite sure where exactly to start. It's probably already been done several times and I'm just wanting to package it differently. I want a battery power light with a simple delay-ON via a clickable switch (pressing again turns it off). I'd like it to run off a CR123 in some way since I have a lot of them. Something in the 200-300 lumens would be great. Beyond that, I'm at a loss on where to begin. I have a couple books I've been studying but they are a bit advanced for what I'm doing. Any help would be appreciated.