Re: Cateye Micro Halogen Headlights HL-500II vs. MC-200?

Peter Cole wrote:
Bill Baka wrote:

SMS wrote:

Bill Baka wrote:

It wasn't made up. I am an electronics engineer by trade and the quantum physics are there for anyone to look up if they can understand them. The only heat loss is in the resistors used to limit the current to the LEDs so they don't get too much current and burn out.




In fact, managing the heat generated by the high power LEDs is very difficult, and Lumileds has whole papers dedicated to the subject.

"http://www.lumileds.com/pdfs/AB05.pdf";



The LEDs do get a little warm but not hot in the sense that anything is going to get hurt.
Bill


The figure used for incandescent efficiency is around 5%. That means 95% of the electrical energy becomes heat. LEDs of the kind used in bikes lights are less than 2x as efficient, so perhaps 10% -- 90% of electrical energy converted to heat. A 5W halogen will generate around 4.5W of heat, a 5W LED 4W, only slightly less -- there are electrical and optical losses which have nothing to do with quantum physics.

I didn't claim it was perfect, but research is going nuts on solid state light sources and hot filaments are soon to be a thing of the past.
The main driving factor right now is not bike lights but cell phone and play station lighting for maximum battery life. They are even getting into organic LEDs, or OLEDs, so a chemically fueled bioluminescence is not too far fetched in the near future.
I am happy with my Cateye for now.
Bill
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