[Rhodes22-list] LED Navigation Lights available from Ancor

[Michael D. Weisner]

John,

The R22 List never ceases to amaze me.  The diverse nature of topics
discussed makes it worth slogging through some of the less than humorous
political diatribes and the all too serious "jokes".  We have now
transitioned from lightning to lighting.

The website that you cited (otherpower) has some very interesting methods of
measuring LED luminance, ignoring the nature of the emitted light.  While
they claim that the lumens/watt generated by an LED are not any greater than
those of a standard incandescent lamp, they have overlooked several
important facts that make LEDs a valuable lamp replacement.

Firstly, the LED should be "aimed" towards the anticipated observer.  As you
have noted, this is done with a bank of LEDs covering an arc.  The problem
with a "bulb replacement" LED product is that you may not be able to
properly aim the LED output, being at the mercy of the orientation of the
bulb socket.  This is why some of us have opted for a complete running light
(or anchor light) replacement unit and may be the reason for the non-marine
classification of the bulb replacement unit.  The orientation of the socket
will determine the effectiveness of the LED as a direct replacement.

Secondly, when properly installed, LEDs should give considerable power
saving over incandescent lamps as a result of the collimination of the light
output.  Less lumens are required to cover the same distance and make the
point source of light appear brighter (without any reflector or lens), even
if they are not.

Lastly, LED light sources require little if any routine maintenance.  There
is no filament to burn out and if designed properly, they will outlast the
useful life of a boat.  Several of the LED based navigation illumination
products have eliminated the bulb style contact arrangement in favor of a
more reliable connection scheme, removing yet another failure mode.

Just trying to shed some light,

Mike
s/v Shanghai'd Summer

From: "John Lock" <jlock at relevantarts.com>


> At 07:35 PM 7/31/2006 -0400, you wrote:
> >Now that's interesting.  This was also true on the other LED
> >choices.  I wonder that they must go through a beaucratic approval
> >process - probably doing all of that now.  Thanks for the heads-up,
> >Bill.  They identify them as equivalent to the approved non-LED
> >bulbs, suggesting for nav use also.
>
> Actually, I think there is is a very good reason for that.  LEDs, by
> nature, give off a very narrow cone of light, as compared to
> incandescent.  Which means if you place one on your masthead, most of
> the light will be shining up, not out where you want it.  Some of the
> replacement bulbs may actually be banks of several LEDs arranged to
> throw out light to the sides or placed under some kind of dispersing
> lens.  However, if you have a bank of several LEDs to get the
> coverage area you want, you may not be saving much energy over a standard
bulb
>
> You can get some good information comparing various lighting sources
> at http://www.otherpower.com/otherpower_lighting.html
>
> Cheers!
>
> John
>
> "Would it help to confuse it if we run away more?"
>
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