Can you buy commercially made LED bulbs to replace incandescent bulbs?
wylbur37
several websites that show you how to convert existing flashlights to
use LEDs by installing an LED and a resistor into a old incandescent
bulb base), there must be commercially made LED bulbs that simply
screw into existing bulb sockets, aren't there? I mean, it would only
seem logical.
I presently have an "itty-bitty booklight" whose incandescent bulb is
rated "4.8V 0.5A" which burns out after only about 15 hours of use. At
$3.00 each, that's rather expensive, and I'd like very much to replace
that bulb with an LED bulb.
So rather than having to build one myself from parts, is there a place
that sells them ready-made (preferably a retail store in New York City
but mail-order is OK too)?
exray
> Because LED flashlights have gotten so popular, (and there are even
> several websites that show you how to convert existing flashlights to
> use LEDs by installing an LED and a resistor into a old incandescent
> bulb base), there must be commercially made LED bulbs that simply
> screw into existing bulb sockets, aren't there? I mean, it would only
> seem logical.
Yes they exist. I don't know if there are any specifically for
flashlights but there are for regular panel and indicator lights. They
tend to be rather pricey. Mouser carries them.
-BM
Nigel Cook
news:8028c236.04041...@posting.google.com...
I'm not familiar with the bulbs you speak of but
over the years I've adapted numerous halogen bulbs
to differnet sockets by crimping wires together of new bulb
( minus base ) and old bulb mount melded together with fire-cement
used for sealing flues to gas fires etc ) .
electronic hints and repair briefs , schematics/manuals list on
http://homepages.tcp.co.uk/~diverse
Andrew Rossmann
the cited author.]
In article <8028c236.04041...@posting.google.com>,
wylbur3...@yahoo.com says...
For anything LED related, check out the LED Museum. He has reviews of
just about anything involving LED's, including replacement bulbs:
http://ledmuseum.home.att.net/
--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.att.net/~andyross
Watson A.Name - "Watt Sun, the Dark Remover"
Watson A.Name - "Watt Sun, the Dark Remover"
news:vteg70lvh8vsd65l3...@4ax.com...
> On 10 Apr 2004 03:53:21 -0700, Bob Horvath wrote:
> This is interesting
> http://flashlightreviews3.home.att.net/reviews/everled.htm
I'm not knocking the Everled, but at $40 and 1Watt, it's a bit of an
overkill for what he wants. About 3 regular 50 degree white LEDs and a
current limiting resistor for each, would cost under $5 with shipping.
See
http://www.whitelightled.com/ for 50 degree white LEDs for a dollar
each.
JeffM
Hell, you can buy a whole LED-lit house ready-made.
http://groups.google.com/groups?&threadm=K7nNb.16006%24QW4.174589969%40news-text.cableinet.net&rnum=15&prev=/groups%3Fq%3Dthevospad%2BAglionby%26num%3D100%26hl%3Den%26lr%3Dlang_en%26ie%3DUTF-8%26oe%3DUTF-8%26safe%3Doff%26scoring%3Dd%26filter%3D0
Don Klipstein
The best white LEDs are only a little more efficient than incandescents,
and the most efficient laboratory prototype white LEDs that I have heard
of so far have efficiency about that of better compact fluorescents.
Please note that incandescent lamps have significant economies of scale.
Lower wattage ones have thinner filaments that must be operated at a less
favorable lower temperature for the same life expectancy, or must have
life expectancy compromised to achieve the same efficiency as higher
wattage incandescent lamps. A 1-watt flashlight bulb rated to last 15
hours has efficiency similar to that of a 100 watt lightbulb rated to last
750 hours. 1-watt incandescents with life expectancy 750 hours or more
have efficiency much less than the 16.9-17.5 lumens/watt of 100 watt 120V
incandescents rated to last 100 hours.
Really good white LEDs in current production achieve 20-30 lumens per
watt, and even that can be a little optimistic. I have heard that a top
rank of an especially efficient model by the manufacturer best known for
making the most efficient ones in recent production over the past year or
two may achieve or slightly exceed 40 lumens/watt, but this is not their
usual current production of that model.
Screw-in "medium base" LED "bulbs" are available from:
LEDTronics (http://www.ledtronics.com)
ETG Technology (http://www.etgtech.com) - with possible minimum orders of
size suitable for direct order from a manufacturer's sales office
Bivar, http://www.bivar.com - theirs may be the ETG ones, and smaller
orders may have to go through their distributors of theirs such as Future
Electronics (http://www.futureelectronmics.com), and distributors may
impose minimum orders and may make you wait for them to order stock.
Please check pricing of small quantities through distributors before
pestering the manufacturers.
Expect prices to be high enough to make white LED "bulbs" uneconomical
for general lighting. The news is not as bad for colored ones, since
there are red, orange, yellow, green and bluish green LEDs with efficiency
like that or exceeding that of white LEDs. Although blue LEDs are less
efficient than white ones, it is easy to find ones with efficiency much
more than that of blue-filtered incandescent lamps.
For example, LEDs do achieve major energy savings over incandescents in
traffic lights. (Traffic light bulbs generally have to last 8,000 hours
or maybe sometimes more, and have efficiency around 11-13 lumens per watt
- and the red and green "lenses" only let through something like 30% of
the light, resulting in an overall efficiency of somewhere around 4 lumens
per watt, maybe only around 3 lumens per watt.)
I mention more in:
http://www.misty.com/~don/lede.html - where and why LEDs achieve
efficiency much more than that of incandescents, and why not for general
room lighting
http://www.misty.com/~don/led.html - some bright/efficient LED models
http://www.misty.com/~don/ledx.html - my LED "top page"
http://www.misty.com/~don/light.html - my "lighting technology top page"
- Don Klipstein (d...@misty.com, http://www.misty.com/~don/index.html)
Don Klipstein
>"Bob Horvath" <bhorv...@comcast.net> wrote in message
>news:vteg70lvh8vsd65l3...@4ax.com...
>> On 10 Apr 2004 03:53:21 -0700, Bob Horvath wrote:
>
>> This is interesting
>> http://flashlightreviews3.home.att.net/reviews/everled.htm
>
>I'm not knocking the Everled, but at $40 and 1Watt, it's a bit of an
>overkill for what he wants. About 3 regular 50 degree white LEDs and a
>current limiting resistor for each, would cost under $5 with shipping.
>See http://www.whitelightled.com/ for 50 degree white LEDs for a
>dollar each.
For use with four 1.5 volt cells, use a 100 ohm resistor with one LED
(or one of these resistors for each of more than one LED) if you want to
be conservative (LED life expectancy around 10,000 or in the 10,000's of
hours assuming no heat buildup problems). You should be able to use a 47
ohm resistor without any immediate blowouts, although the life will
probably be compromised, easily seriously compromised.
Be aware that this one, at the maximum rated current of 30 mA, produces
only somewhere around 2-2.5 lumens of light. The PR13 "4-cell" flashlight
bulb at its rated 4.75 volts (while consuming .5 amp) produces about 25
lumens of light (and is rated to last 15 hours at 4.75 volts).
The directional LED may do as well with 1/10 as much light as the
flashlight bulb does if the flashlight bulb has no reflectors. Just
remember that with a 50 degree beam you may need the LED to be a foot away
from your book to illuminate it! You may want more than one LED - beware
of heat accumulation in LED cluster lamps!
- Don Klipstein (d...@misty.com, http://www.misty.com/~don/ledx.html)
Syd Rumpo
<d...@manx.misty.com> writes
[snip]
> Expect prices to be high enough to make white LED "bulbs" uneconomical
>for general lighting. The news is not as bad for colored ones, since
>there are red, orange, yellow, green and bluish green LEDs with efficiency
>like that or exceeding that of white LEDs. Although blue LEDs are less
>efficient than white ones, it is easy to find ones with efficiency much
>more than that of blue-filtered incandescent lamps.
Don, would it be possible to emulate 'white' light using a combination
of yellow and blue LEDs. I appreciate that it wouldn't actually be
white, and the colour rendering would be poor, but as long as it *looks*
white it would be ok for, say, bicycle lighting. Would such a
combination be as efficient as an incandescent?
--
Syd Rumpo
Watson A.Name "Watt Sun - the Dark Remover"
> [snip]
Actually you need RGB, red, green and blue. For bike riding, a beam
that can see several yards ahead is needed, so LEDs aren't a good choice
because it takes a lot of them to make a strong beam, and that gets
expensive.
Syd Rumpo
the Dark Remover\"" <NOS...@dslextreme.com> writes
I think blue and yellow should do it, the point is to excite the eye's
RGB receptors to roughly the same degree as white light would. Aren't
white LEDs really blue ones with a yellow phosphor?
As for the expense, yes they are expensive, but a 5W LED would be bright
enough for most front light applications. I use 10W incandescent, but
they're relatively fragile and quickly dim as the battery runs down. In
one way, that's a disadvantage of LEDs for battery lighting: it's hard
to tell when the battery's low because the colour doesn't change.
--
Syd
jakdedert
Check out this new stage lighting fixture:
<http://www.premier-lighting.com/sales/led.html > or this line of products
from the folks who produced the 'phantom' WTC :
<http://spacecannon.it/catalogo.asp?lingua=english&tipo=indoor> or this
architectural treatment of Londons Apollo Victoria Theatre:
<http://www.etnow.com/news/features/stageapollo/> or from LumaLed
http://www.lumileds.com/solutions/solution.cfm?id=3 this piece of info "High
Power Arrays of Luxeon using fewer than 70 Watts can replace a 1000 Watt
lamp in a PAR64 and do so with longer life, greater reliability, digital
control and without heat in the beam." Then there's this nifty little
fixture which puts out 254 cp in white, using color mixing:
<http://www.colorkinetics.com/support/datasheets/ColorBurst6.pdf>
I think it's pretty obvious where the future of illumintation lies. For the
most part, it's LED's...not just in flashlights, but for almost all normal
applications. The advantages are just too overwhelming. I don't expect to
see LED's replacing stadium lighting any time soon, but who knows?
jak
Watson A.Name - "Watt Sun, the Dark Remover"
"Syd Rumpo" <sydr...@clarat.co.uk> wrote in message
news:gUs4ZFFl...@ntlworld.com...
The phosphor is a very broad emitter somewhere in the amber or yellow
orange.
See
http://www.mse.berkeley.edu/classes/matsci102/F01reports/whiteled.pdf
> As for the expense, yes they are expensive, but a 5W LED would be
bright
> enough for most front light applications. I use 10W incandescent, but
> they're relatively fragile and quickly dim as the battery runs down.
In
> one way, that's a disadvantage of LEDs for battery lighting: it's hard
> to tell when the battery's low because the colour doesn't change.
The problem is that the light must illuminate the area several yards
ahead. If it doesn't, then you're not going to see the road ahead. If
the LED doesn't have the narrow beam you need, then it won't be able to
do the job.
Putting a LED (or several LEDs) into a regular reflector for
incandescents doesn't help. Using a lens helps somewhat but the lens
wastes a lot of light. Seems that the only maker that has done a decent
job of making a special lens for LEDs is Lumileds Luxeon Star /O with
the special lens that's added on.
> --
> Syd
>
jakdedert
Since you have done such a good job of research, it's surprising that you
didn't realize that the auto headlight application has already been done in
LED's--by Lumiled--two years ago.
From:
http://lightingdimensions.com/ar/lighting_show_report_lightfair/index.htm
"Lumileds, a division of Philips Lighting and Agilent Technologies, lit its
entire booth with LEDs from OEMs that use its LEDs. The entire booth drew
1,100W of power! On display were some very interesting products including
step- and edge-lights as well as a thin shelf and under-cabinet system that
fully illuminated the cabinet when the doors were opened. *Also shown was a
car headlamp made up of ganged LEDs that meets the auto industry's standards
for brightness and distribution.*"
jak
>
>
>> --
>> Syd
Watson A.Name - "Watt Sun, the Dark Remover"
"jakdedert" <jde...@bellsouth.net> wrote in message
news:hYcfc.42797$Lh2....@bignews1.bellsouth.net...
[snip]
Well, hey, what'd I say about Lumileds? ;-)
Looks like a lot of the auto mfgrs are making custom reflectors for the
LEDs in their taillights. They don't act like regular incandescents, ya
know.
> jak
Watson A.Name "Watt Sun - the Dark Remover"
> news:hYcfc.42797$Lh2....@bignews1.bellsouth.net...
>
> [snip]
> Looks like a lot of the auto mfgrs are making custom reflectors for the
> LEDs in their taillights. They don't act like regular incandescents, ya
> know.
>>jak
I found this URL that says that regular 5mm white LEDs degrade to 70%
brightness after only 3000 hours. This confirms my empirical
experiments with some LEDs that I've had running since before xmas.
See page 2, paragraph 4.
http://www.lumileds.com/newsandevents/releases/May_06_2003_Warn_white.pdf
jakdedert
Three thousand hours is a long time in a flashlight...typically several
bulbs worth, assuming the bulbs don't fail from shock first. Compared to
the little halogens in a mini-maglite, 70% is still several times brighter
(assuming equal output when new) than end-of-life out put for the halogen.
Someone else pointed out something I had forgotten about halogens: namely
that the silvering of the envelope accelerates under lower than rated
voltage, due to the fact that the filament does not regenerate itself as it
does in a full-voltage condition. Of course, batteries--especially
alkalines and carbon/zincs--spend most of their useful life at less than
'fresh' voltage....
jak