jack in the matrix
Newly Enlightened
- Joined
- May 22, 2012
- Messages
- 11
Been running dynamo lights on my 2 bikes (summer-winter/wet) for a few years now. I run them day or night, and they've been trouble free until now. The taillight has just burned out on the summer bike.
Both have the same circuit - Martins circuit 7 for 3 LEDs, with a super cap across the taillight and first headlight, and Frontrangers tweak to fully charge super cap. Got 2 neutral white XML2 headlights on the winter bike, P7s on the summer bike, and a red XPE taillight on both.
The dead XPE is rated for 700 mA, had only 2 years of limited use, and was bright enough to get comments in broad daylight. I thought it was running close to its max, but this early demise has me wondering. Could my tuned and tweaked circuit, powered by an SP hub, be the culprit? Don't have a clue how tuning caps work, but I've always used them, and the output is very good. Can they draw more than 500 mA out of the dynamo? I'm skeptical.
I think more likely it got cooked. The LED is in a MagicShine housing (decent heatsinking) mounted under the saddle (lousy airflow?). Have ridden the bike alot recently, including several longer rides (2 hours +), in mid-summer heat (25 C +). Any input would be appreciated before I rebuild the system.
Both have the same circuit - Martins circuit 7 for 3 LEDs, with a super cap across the taillight and first headlight, and Frontrangers tweak to fully charge super cap. Got 2 neutral white XML2 headlights on the winter bike, P7s on the summer bike, and a red XPE taillight on both.
The dead XPE is rated for 700 mA, had only 2 years of limited use, and was bright enough to get comments in broad daylight. I thought it was running close to its max, but this early demise has me wondering. Could my tuned and tweaked circuit, powered by an SP hub, be the culprit? Don't have a clue how tuning caps work, but I've always used them, and the output is very good. Can they draw more than 500 mA out of the dynamo? I'm skeptical.
I think more likely it got cooked. The LED is in a MagicShine housing (decent heatsinking) mounted under the saddle (lousy airflow?). Have ridden the bike alot recently, including several longer rides (2 hours +), in mid-summer heat (25 C +). Any input would be appreciated before I rebuild the system.