> The loss of efficiency in rectification and regulation has been
> explained here numerous times. I'm sure you can google it. Unlike
> "darned bright" the loss of efficiency is an actual quantifiable number
> based on the buck-boost regulator efficiency and the efficiency of a
> full wave bridge rectifier.
Again: People have successfully commuted for decades using halogen
headlamps powered by generators. People have successfully competed in
all-day-all-night audax rides using the same equipment. Its silly to
pretend that sort of system is inadequate for those uses.
Generator powered LED lamps have now reached the level where they are
better than halogen. They put out even more light with even less
effort. That's the sort of efficiency that matters.
I recall the generator test article at
mentioning that the drag caused by really good generator sets is
equivalent to climbing ten feet per mile or less. That's a good
illustration of "negligible." And since the forward voltage of a
typical LED is less than that of a halogen bulb, I'd expect even less
drag if those same generators are powering an LED.
So what if the system includes a full wave rectifier that slightly
reduces that efficiency? Drag is still going to be less than with the
halogen - that is, less than negligible. Your theoretical drop in
efficiency just does not matter in any practical way.
- Frank Krygowski