Daisy,
That's a good outfit, I bought my eMeter from them.
<<Jim>>
D Welch wrote:
>
> Anyone who is interested in alternate lamps would be thrilled with the
> Jade Mountain catalog. It costs $8.00, and has lots of different
> flourescents and LED's in a myriad of configurations.
>
> There are a lot of other 12v things too, way more than on the web site.
> kept me happy on the throne for a good month.
>
> Daisy
>
> Dr. Gerald N. Johnson, electrical engineer wrote:
> >
> > I've been doing some studying. My Caravel has three ceiling fixtures,
> > each with four 1141 lamps. The rotary switch allows selecting 1, 2 or 4
> > lamps at a time, 17, 35, or 70 watts. Each 1141 is rated at 21 candela.
> >
> > I looked at white LEDs. The largest output I found without digging too
> > hard was at Hosfelt Electronics, (www.hosfelt.com), 7000 millicandela,
> > or 7 candela. 1/3 the light output of an 1141. The power to the white
> > LED is 4 volts at 20 milliamps, .08 watts. Its not a drop in part yet,
> > the LED costs $5.99 each and requires current regulation to protect it
> > from large changes in current with small changes in voltage. 3 in series
> > should be close to working directly from 12 volts with a bit of current
> > control. I'm thinking about circuits. The other problem which may be an
> > advantage in some applications like reading lamps is that the beam is
> > narrow, maybe 28° included angle. For general trailer lighting this
> > could be a limitation. There are multiple solutions, the conceptually
> > simplest one is a cluster of LEDs each at a different angle to fill in
> > the hemisphere of lighting needed for general ceiling lights. I'm
> > thinking some sort of spreading lens or reflector or a combination of
> > the two might be practical. It might even be practical to defocus the
> > dome on the front of the LED. I wasted many red LEDs a few years ago
> > trying to make them focus tighter... Dispersion was far easier to
> > accomplish.
> >
> > I've ordered three of the LEDs from Hosfelt. They seem to promise the
> > same light level (if it can be spread enough) for 1/100 the power.
> > That's far better than the fluorescent fixtures.
> >
> > Its harder to find fluorescent fixtures using compact fluorescent lamps
> > to run off 12 volts. Most use either the 5/8" diameter by 4 to 8"
> > tubular lamps or circuline lamps. Neither are great for efficiency or
> > commonly available in improved colors, though are very commonly
> > available as 12 volt operated fixtures and as replacement lamps.
> > Generally the small tubular lamps and compact fluorescent lamps are
> > rated at different powers so their ballasts can't be swapped
> > successfully.
> >
> > The first batch of white LEDs should be here about Thursday, then I can
> > begin to experiment.
> >
> > 1141 lamps are on the hooks at Walmart in automotive lights. $1.97 for a
> > blister pack of two. There's also 12 volt 18 watt lamps in a similar
> > package in the RV section, $.97 for a blister pack of two.
> >
> > There is a single LED flashlight at Walmart (flashlights are in sporting
> > goods) for $11.96. It runs on 2 AA alkaline cells.
> >
> > Gerald J.
> >
> > To unsubscribe or to change to a daily Digest, please go to
> > http://www.airstream.net/vaclist/listoffice.html
> >
> > If replying back to this message, please delete all the unnecessary original
> > text from your reply.
> >
> >
>
> To unsubscribe or to change to a daily Digest, please go to
> http://www.airstream.net/vaclist/listoffice.html
>
> If replying back to this message, please delete all the unnecessary original
> text from your reply.
>
>
--
<<http://www.oldengine.org/members/jdunmyer>>
<<[EMAIL PROTECTED]>>
<<lower SE Michigan, USA>>
<<mailto:[EMAIL PROTECTED]>>
To unsubscribe or to change to a daily Digest, please go to
http://www.airstream.net/vaclist/listoffice.html
If replying back to this message, please delete all the unnecessary original
text from your reply.
