I have kind of an LED fetish. I also like to ride my bike for transportation and fun, both of which are risky ventures here in Houston.

The human eye is most sensitive at 505nm while dark adapted and at 550nm while light adapted. The eyes of driver at night with dashlights is probably somewhere inbetween, closer to light adapted. It just so happens that an LED centered at 525nm exists and is easily available. I borrowed a circuit design using a CMOS 555 to pulse three of these LEDs for about 1 ms at 1-2 Hz which is definitely enough to get a drivers attention for at least half a mile. I built one and let it run for a week in a box and yes, after ~150 hours of continuous operation the intensity of the pulse was diminshed but still better than other flashers I've seen.

The only problem I could see with using green is contextual contrast or "green means go". I used to have one of those 5 LED red flashers with different blink patterns which runs off of 2 AA batteries. You know the one I'm talking about the cheapies everyone had for a while. It simply doesn't have the dazzling ability of the green LED to grab attention. Besides, the dark adapted human eye has NO red sensitivity.

I've yet to make a bikeable modle, packaging is the issue now. I thought about wire wrapping the circuit and LEDs as compactly as possible and feeding 2 9V wires out of the bloblett but I don't know exactly what I'm looking for in terms of epoxy-resin.

If the circuit lingo puts anyone off, please don't be. It's not that complicated of a circuit even if you don't know much about electronics.