K4556 wrote:
On Mon, 19 Mar 2007 08:16:25 -0800, Gordon wrote:

A lot of commercial fishing boats spend the night at sea drifting. To
be seen better, they use a strobe light. Legal or not, they want to be seen.
I/m thinking an all around white LED anchor light could be wired to a
relaxation oscillator or 555 timer chip to create a low current draw
white strobe. Yes? No?
Gordon


Certainly you could build a 555 powered on-off system to blink an
anchor light on and off and you would have a blinking light. Of course
a "Strobe" is a somewhat different beast as it is a flashing BRIGHT
light and much more likely to be noticed at a distance.


Ibid
(k4556ATinetDOTcoDOTth)


I suspect the objectives are to reduce power consumption (which, for an
LED is likely to be small anyway) and to increase noticeability by
blinking.

Whether pulsing will increase the LED's apparent brightness (relative to
the normal, unpulsed anchor light) depends on how the anchor light was
designed, and the type of white LED involved. Many white LEDs produce
their maximum output at something like 20 mA so high-intensity pulsing
may not increase output. If the anchor light uses something like the
Osram Golden Dragon (2 watt) white LED, that would certainly be noticed
if pulsed, say, once per second! Not as bright as a strobe, but a whole
lot better than many anchor lights now in use.

Actually, in fog or mist, yellow anchor lights might penetrate better
(i.e., not be reflected by water droplets) than white ones with a lot of
blue in their spectral output. Like fog lights on cars.


Chuck

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