In ,
JIMMIE wrote:

On Apr 27, 10:58*pm, frank1492 wrote:
I will be mounting this externally in view of the neighbor's house on
a seasonal cottage. I make few trips there in the winter, *but would
like to have the neighbor (all year round resident) be easily able to
tell me if my power is off. (He has a phone, there is none at the
cottage.)
* * What should I use, neon, led,etc? It needs to be wall mountable,
and be easily seen, though it need not be very bright or large.
* * Suggestions appreciated. I just want to be sure it has a long
life so a burnt-out bulb won't be confused with no power.
* * Thanks in advance.
* * * * *Frank

There are LED lamps that just screw into a regular 120 vac Edison
Socket. I saw some the other day for about $8USD. Just screw into your
porch light socket. They use about 1 watt and there light output is
the equivalent to a 20 watt incandescent bulb.

A 25 watt incandescent produces 180-230 lumens, and a 15 watt one
produces usually 100-120 lumens. I have yet to see any LED lamps on the
market achieving this sort of light output with one watt, though I have
seen a lot of claims that I find hard to believe.

===================================

Many white LEDs fade at a significant rate with use. Some better high
power ones will fade by only 30% in 50,000 hours if they are kept
sufficiently cool. Many low power white LEDs will fade 30% or more in
6,000-10,000 hours. I have known one white LED nightlight to fade by
about half in about 4,000-4,500 operating hours.

Most red, orange, amberish-yellow, green, blue-green and blue LEDs have
good prospect of lasting the 100,000 hours that is widely claimed for life
expectancy of LEDs, as long as they are not overdriven and not allowed to
overheat.

UV, violet, purple, pink, pastel, and "phosphor yellow"
(generally less orangish than "school bus yellow", sometimes a hair
greenish) tend to have issues affecting life expectancy - expect 50,000
hours or less from most of these. Many UV ones with epoxy or plastic
bodies have UV output fading significantly in mere hundreds of hours at
"full power", and many similar violet ones fade significantly in several
hundred to a couple thousand hours. Many UV and violet ones with
all-inorganic construction are only rated to last 50,000 hours.

Pink, lavendar/purple and other colors depending on phosphors will
likely last 50,000 hours optimistically, maybe merely 6,000-10,000 hours.

===================================

The 3-LED "C7" Feit Electric unit appears to me likely to last the claimed
50,000 hours or at least get a majority of the way there despite having
white low power LEDs. The LEDs in that unit are operated at highly reduced
current, maybe about 3.3-3.4 milliamps, about 16.5-17% of the usual 20
milliamp "characterizing current" of most low power LEDs where life
expectancy is maybe 6,000-10,000 hours when doing well. 3.3-3.4 milliamps
is about 11% of the rated maximum current of most of such LEDs.

The LED nightlight that I found to fade by about half in about 4,000
hours has the LEDs passing current close to 30 mA.

- Don Klipstein )