At 10:26 AM 6/28/2006 -0300, you wrote:


>- http://www.zeit.de/stimmts/1999/199933_stimmts_gluehbir (German):
>Since 1924, an international cartel (?) consisting of GE (USA),
>Osram/Siemens (Germany) and Assoc. Elect. Ind. (UK) divided up the world
>market between themselves and also defined the "durability point" at 1000h.
>Making the filament stronger increases durability by decreasing the energy
>efficiency. Chinese lamps seem to be designed for 5000 hours (not part of
>the cartel :). Since energy cost is a major factor of the lifetime cost of
>a lamp, it may not be beneficial (financially) to increase the lifetime
>(see also below). They don't give sources, and the companies probably
>wouldn't publish their contract, so this is "leaked classified
>information", at most :)

Or maybe just an attempt to create a reasonable industry standard for
life and energy efficiency.

As you listed in your post, lifetime curves of voltage vs. hours and
efficiency vs. voltage are easily available. If don't mind a reddish
light and poor energy  efficiency (a 25-cent bulb will burn much more
energy than that over its lifetime), then you can dim the bulb or buy
a 130V bulb for 120V  use. Until I put compact fluorescents in our
garage door opener it had heavy duty (even worse energy efficiency due
to the heavy filament and supports) 130V bulbs to withstand the motor
vibration. As it's only on for a few minutes a day, energy efficiency
wasn't a big deal. At the other end of the spectrum (so to speak),
photoflood lamps have a blue-white light and high energy efficiency, but
last an average of only 6 hours. I have a lit bundle-of-branches
'tree' in my office (Josh K. has seen it) that has white Xmas-type lights
on it. I replaced one of of the (series string) bulbs with a (carefully
insulated) 1N4007 to knock the voltage down to 70% of line and get several
years lifetime 24/7.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
->>Test equipment, parts OLED displys http://search.ebay.com/_W0QQsassZspeff


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