In article ,
Don Foreman wrote:

The apparent brightness is the same if the average current is the
same. Pulsing them does not make them look brighter.

This assertion is based on an experiment I did today.

I ran two identical red LED's (automotive brake-turn parts if it
matters, LiteOn LTL 912-VRKSA), one with DC current and the other
getting pulses of 10X that current with a 10% dutycycle so the
average current was the same.

I ran this at a variety of currents and frequencies. In every case,
the LED's looked identical and indistinguishable unless the frequency
was low enough so there was noticable flicker. At 40 Hz, where there


Try varying the duty cycle, at a fixed current/frequency (say 1000 hz,
something up out of noticable by a good ways). IIRC, running one this
way the apparent brightness hit a plateau (visually indistinguishable to
an LED running the same current 100%) somewhere between 30-50% duty
cycle.

Take that duty cycle and ramp the current up, and you might get a more
noticable difference in output. In specific, if the rated current of the
LED is 20mA, and you find no noticable brightness increase between 50%
and 100% on time, you should see a difference when you run 40mA at 50%.

It has been 16 years or so since I ran that experiment, but I recall it
reasonably well.

--
Cats, Coffee, Chocolate...vices to live by