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Answering
the question of the life of FLATLITE, for any electroluminescent
based
product,
is a somewhat long answer.
EL does not
fail to light so it technically has NO end of life, rather
it is the decaying
luminance level (brightness) in a particular application that determines
when it is no
longer useful.
The decaying
luminance is exponential - meaning more rapidly early and
extremely slow later in time, which is also greatly affected by how the
phosphors are
powered (this means the inverters output wave shape, voltage and frequency)
and by the ambient temperature the lamps are being run in (cold temperatures
yield better results than warmer temperatures).
All EL technologies
share the same characteristics with the major variation being
the
quality of the base phosphor material with the secondary factor being the
way the lamp is manufactured.
The phosphors
available from each manufacturer are graded according to
their specific life and brightness characteristics. If the same exact grade
is being used by two manufacturers, their methods of making or driving
the lamp may produce results that differ as much as 25%. This is why the
decision to use EL technology for an application should be independent
of what a particular supplier may quote for "life".
Comparing
two EL technologies must be done with all the factors (power,
temperature,
phosphor grade) equal, which may not be possible given the data normally
available from the different manufacturers.
Our Flatlite
inverters employ an active compensation scheme, so more voltage
is fed to the lamp as it ages early in its life. This compensation
scheme, combined with variable starting brightness levels,
greatly varies the useful life of a product. In one test, for
example, samples were run at 25, 50, 75 and 100% starting voltage.
After 2 years of running 24/7, the lamp started at the 25%
level was the brightest of the 4 samples and the other 3 were
virtually the same.

In Signage
applications where the brightness required is high but the on
time (duty cycle) is only the night time hours as
in a bus or taxi sign, the Useful life is approximately
12 18 months.
In Aisle
Lighting applications like Movie Theaters, both the brightness
is low and the duty cycle is low resulting in a Useful life
of 5 years or more.
In outdoor
Architectural Lighting applications, the required brightness
is relatively low but the duty cycle is about 50%. The Useful
Life of this type application can be
3 5 years. EL lamps do not burnout, in time they will
become dim enough to
require replacement.
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