I built a LED light for my winter bike, using diagram #2 at pilom.com . I used a bridge rectifier I had laying around with a 1000 uf cap. The power source is a Sturmey-Archer X-FDD (dynamo Drum) hub. It produces 6v, 3w. The Power LED is a Cree XR-E-R2 LED from Deal Extreme. I used JB weld to attach the star to the head of a bolt, with a large brass nut for heat sinking. It's very bright and seems to work fine.
I have two questions:
My first question is whether or not I am damaging the LED. I showed the setup to someone at work, and he said the 6V from the dynohub will burn up my LED. I thought I read somewhere on here that these LED can handle the current and the voltage isn't a problem.
The second question is about a tail light. While Pilom has some circuits for tail lights, could I just add a Red LED in series to the white front LED? That would be easier to wire.