Wayne Boatwright wrote:
On Sun 27 Apr 2008 08:32:16p, Don Klipstein told us...


In article 4, Wayne
Boatwright wrote in part:


Another option I've used in very old lighting with two bulbs is wiring
them in series. The bulbs last forever and the color and intensity is
just right. I have one fixture that remains on constantly, that the
bulbs are probably 30 years old or older.

As an aside, it's been said that Edison's home in Florida that is wired
with DC power still has the working original bulbs throughout.

Just keep in mind that such century-life incandescents have energy
efficiency so low that in order to produce a given amount of light, you
increase your electric bill more than you decrease your lightbulb
replacement costs.

The first-mass-marketed carbon filament incandescents had energy
efficiency of a couple to at most a few lumens per watt.

There is a "centennial bulb" with a webcam showing a publicly
accessable
view of it continuing to work. I give low odds of its energy efficiency
exceeding that of a 230 volt incandescent being powered by 120 volts, or
roughly 1/4-1/3 that of modern 60-100 watt 750-1000 hour incandescents.

http://www.centennialbulb.org

- Don Klipstein )


I've no doubt of the inefficiency, but thought it was interesting, and
I've seen the Centennial Bulb before. Just thought it was a curiosity.

As a further aside, my dad had a habit of installing double light fixtures
with 25 watt bulbs at strategic places throughout the house and basement,
wired in series, to produce a very low light level. He didn't like walking
into dark rooms, especially when the light switch wasn't near the entry.
To him, of course, this wasn't a waste of energy. Of course, this was in
an era when energy consumption was not an issue or concern.

Hi,
For low lighting I use LED bulbs. They consume only 3W per bulb.
Few different colors. Soon I hope LED will replace CFLs.