Date: Sat, 29 Apr 2000 18:33:59 -0400
Reply-To: David Beierl <dbeierl@IBM.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@IBM.NET>
Subject: Reading lights
In-Reply-To: <029701bfb0c7$3cf2f880$ac0a7418@default>
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Hi Jeanne -- I'm not sure what to tell you -- I've never seen one of these
lights. Here are some thoughts, though:
You're consuming about 0.07 watts per LED. A small bright flashlight like
a Mini-Mag (2 AA, supposed to be good for 45 minutes) uses about 2 watts on
a fresh set of batteries. It may or may not be as efficient as the LED,
but it's working with about 30 times the power. I guarantee the LED is
nowhere near 30 times as efficient. It *might* be three times as
efficient, but I suspect it's more like evens or half as good. I've built
LED "bulbs" in yellow for such flashlights when I wanted *lots* less light
along with long battery life. The sort of light you want when you're
completely dark-adapted and want to look at a chart or something without
wrecking your night vision. Very successful there, but for reading only if
you want to scan the flashlight along each line from about four inches
away. I believe that the white LEDs are significantly brighter than the
ones I was using, but not anywhere near 10 times as bright (subjectively --
when you double the actual light output you get a perceivable brightness
difference, but nowhere near double).
So all in all, I doubt that you'd find a 3-LED fixture satisfying for
reading. However, they say they'll take the thing back if it's not
suitable for your application, if you follow their rules about it, so it
would be worth a try IMHO.
Something I pretty much guarantee you'd be happy with is an adjustable
chart light made by (I think) Aqua Signal -- West Marine should have
it. It is a tube about 2" x 4, with a two-axis gooseneck fitting on a
little base that slides and locks into a small wall mount. They furnish
two mounts with the lamp. It uses a five-watt halogen bulb (about 0.4
amps) and has a rotating polarizer to adjust the output from full (i.e.
about 30% transmission, like the lightest possible pair of polarizing
sunglasses in front of the lamp) down to a dim dim purple (it only turns
color at the very dim end). It has a coiled wire about three feet
long. The rear cap rotates to turn the bulb on and off, and there is a red
slider tab at the front to rotate the filter.
I have been using it for chart work for about ten years now with complete
satisfaction. I have one of the clip mounts to the left and one to the
right of the chart table, so that either leftys or righties can use it
without their working arm blocking the light. It was about $30 at the
time. We're still using the original bulb -- I would guess it's got
somewhere between 50 and 500 hours on it by now. One potential problem is
if you have it set very dim you can forget it's turned on -- you certainly
wouldn't notice in daylight unless you were looking right into the lens.
If I were going to put more lights in the Westy that's what I'd use, with
mounts and jacks in the areas I wanted to be able to use it. Not sure what
I'd use for plug and jack -- there are lots of possibilities. Some people
seem to be using microphone plugs (type A3M male and A3F female, often
called Cannon plugs). They're very suitable, if a bit large. They lock
into the socket.
What we actually use for light is a small clip-on bendable 120V lamp with a
(Sylvania) parabolic reflector high-efficiency fluorescent bulb screwed
into it. It's an 11 watt bulb that runs off a small inverter, draws a bit
over an amp from the battery. The bulb is supposedly equivalent to a
40-watt incandescent. The reflector pattern is such that if we clip the
lamp halfway up the pop-top strut, it lights up the whole central cabin
area brightly. If higher up it also gets the forward part of the upstairs,
but starts shadowing the rear seat area. When we want a reading light we
clip it to something handy like the kitchen overhead shelf. The lamp cost
$5, the bulb was $15-20; but if we don't break it it should outlive the
van. It gives much better light and more comfortable light, and draws half
the current of the built in 25w halogen fixture with the diamond-pattern
lens (in ours it's mounted a bit aft of the trailing edge of the stove,
underneath the shelf). It has survived several crashes to the floor -- the
reflector cups the actual bulb and shields it from most bumps. I've seen
covered versions of the same thing in airport overhead lighting.
At 00:07 4/28/2000, Jeanne Maly wrote:
>David,
>
>I want to add some light to the inside of my Westy. I've been looking at the
>light fixtures on the website that Ron Bloomquist mentioned
>www.theledlight.com
>and I'm just not sure how much light an LED puts out. For example, if I can
>find a place to mount a reading light for the loft, is a fixture with 3 LEDs
>powerful enough to read by?
>
>Jeanne
>
David Beierl - dbeierl@ibm.net
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