"Greg Mayman" bravely wrote to "Mike Ross" (22 Sep 03  08:45:00)
 --- on the heady topic of "VEHICLE LED'S"

 -=> Mike Ross said to Greg Mayman
 -=> about "VEHICLE LED'S" on 09-17-03  10:00.....

 GM> Taking the extremes of your table:

 MR> % rated V  Life      %Candlepower %Current  % Power I/P % Efficiency
 MR> --------------------------------------------------------------------
 MR>    60       500x        10           75        45           22
 MR>   130         0.03x    250          119       155          161

 GM> Note that for the same voltage increase from 60% to 130%, the
 GM> power increases by a factor of 3.44, and the current by a factor
 GM> of 1.58.

 GM> Which of these is closer to constant, that is closer to the same
 GM> value at the higher voltage as at the lower? The CURRENT!

Fine but note that your choice of the other point of comparison doesn't
even produce the rated %Candelpower. The lamp is barely ON! In fact it
is probably glowing yellow-red and making more heat than visible light!
No wonder, since a plot of the filament resistance vs voltage will show
a much greater change near the origin than when the filament reaches the
proper operating temperature. Peaches and pears!!!

 Mike
 ****

... Gender is irrelevant.  Resistance turns me on.
--- Blue Wave/DOS v2.30