[scoot]

So why not just use an appropriate resistor?

[darkarmani]

A resister has a voltage drop related to the current. A diode will always drop the same voltage (within operating parameters).

[nitrogen]

The voltage drop of a resistor is proportional to current.

[iiiears]

So in many appliances the LED serves two functions, Light and part of the active circuit to lower voltage? - This is why HN has for me replaced slashdot and digg. Thank You.