8W LED bicycle light - Version 2

Version 2

Proposed design uses

• 3 x Cree XLamp 7090 XR-E
• 700mA BuckPuck with external control. Full power is 700mA x 3.4V x 3 = 8W giving 400 lumens. Partial power is 200mA x 3V x 3 = 2W giving 150 lumens. Note that these voltages are measured values, which are lower than the typical values on the data sheet.
• Khatod PL353 triple lens.
• Mount these in a 50mm outside diameter tube with 2 or 3mm wall thickness, 70mm long. The lens would overlap the front of the tube, forming the front cover. The only problem with this is that the lens has a hole in front of each LED, so the light doesn't have to travel through as much plastic. While I could use the light this way, it may be difficult to get an insect out of the hole without scratching the lens, or clean the surface after riding in the rain. I might have to glue some flat perspex onto the front.

V1.5 beam, Cree XR-E, Fraen FC-N1 optics	V2 beam, 3 x Cree XR-E, Khatod PL353 optics

That's a serious amount of light, about the same as a 30W halogen.

Electronics parts cost is about $120 for the light, plus $60 for the battery.

Remember to take photos during construction!

Bike light index

2007-02-18