richard@gryphon.COM (Richard Sexton) (11/17/89)
Fluorescent lights have the potential to be very inexpensive
to operate, but sometimes, the cost of running fluorescent lights
is much higher than expected.
The reason for this is the type of ballast used to operate
the light. The ballast converts the electricity coming out
of the wall into the particular flavour of electricity the
fluorescent tube wants to see.
There are two kinds of ballasts: magnetic and elecronic. The
former is by far the most common type, and is little more than
a transformer. It is cheap to puchase. It has the drawbacks
of being noisy (this is the source of the humm, or buzzing
so often ascociated with fluorescent lights) and not
terribly energt efficient. A fixture with two 40 watt bulbs
may actually draw 250 watts.
The electronic ballast is the inverse of the magnetic ballast.
It is NOT cheap to buy, but it is silent and much
more efficient. On the order of 100 - 130 watts to run
two 40 watt tubes.
The state of the art in ballasts seems to belong to the Advance
corperation. They make two models, the REL2S40TP which
is comprised of discrete components, and has been around
for a while, and the newer RIC2S40TP which uses an ASIC
to replace all the discrete components. This unit has
to advantages over the older system. It is a ``smart''
ballast, in that it detects low voltage and maintains
constant luminous output by drawing more current. Secondly,
it will work with any 30 or 40 watt fluorescent tube -
enery saver, T-8's etc.
Thats the good news. The bad news is that they only make
one model. Indeed nobody makes an electronic ballast
that operates anything other that two 40 watt (or 30 watt)
tubes.
The reason for this is, 70% of fluorescent tubes sold
are the 48" 40 watt type, and it is not economical
at this point to manufacture electronic ballasts for
any other tube sizes.
--
``He is good with numbers, but I keep having to tell him how to
work the VCR over and over again'' -- Rajan Mahadevan's roommate
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