Originally Posted by
Doohickie
See in particur post 34:
The small low voltage halogen bulbs have a reported life of 10 to 100 hours and that seems to be dependent on vibration level they are subjected to and luck.
10h does not have much connection to reality. I could just overvolt a bulb right away and claim that the life varies between 3s and 100h. I ride really rough and my lifetimes have been in the region of 200h. 100-200h is plenty, equivalent to several years of riding for most people.
In the particular case, though, I would worry that the standard dynamo would tend to underpower the lamp making the light excessively yellow and dim. However, at least there would be no need to employ a protective Zener.