> From:    Jeff Palmer <jpalmer@MTS.NET>
> Date:    Fri, 6 Apr 2007 01:28:20 -0500
>
> So when are compact flourescents coming to automobiles?

Inside or outside?  :)

For outside lighting other than headlights, probably never.  The
required ballast/control gear will probably always be more expensive and
bulkier than a simple filament lamp or LED.  The accountants don't like
"expensive" and the engineers don't like "bulkier".  You only pay for
"extra" energy for a filament lamp when it's on, but you have to pay to
haul more weight around all the time.

For headlights... maybe someday.  The main problem with fluorescent
headlights is probably designing a reflector to spread light from a
fluorescent tube into an acceptable headlight pattern.  HID lamps allow
for a lot more light output over a relatively short length, so the
reflectors are a little easier to design.

As has been mentioned, LEDs are probably the "next" technology for
everything other than headlights.  It remains to be seen whether the
industry will develop some standard LED modules that can be plugged
into different lens/reflector combinations.  That way if the LEDs do
burn out, you could replace a $5 LED module at the car parts store
rather than replacing a $50 side-marker light at the dealer.  "But LEDs
don't burn out!", you say.  Well, if your alternator never misbehaves,
and if the accountants never substitute the "100 for $1" LEDs for the
nickel LEDs the engineer specified, sure.  :)

Another reason for LEDs is for the alleged 42 V charging system that
will eventually happen maybe someday - 36 V battery, 42 V alternator
voltage.  At this voltage, if you want a 3 W filament lamp for a running
light, you have to make the filament really thin and short - so much so
that it tends not to hold up to the normal vibration experienced in a
car.  On the other hand, 42 V charging systems have been kicking around
for a while now, and they haven't been widely adopted yet.

There is a 2008 Audi that will have LED headlamps.  An acquaintance that
does vehicle lighting feels that this is the first time that forward
lighting technology has been driven by the stylists rather than the
engineers.  I asked him about the possibility of developing a DOT/ECE
legal LED headlamp in the shape and size of a sealed-beam, for retrofit
purposes - he thought it would be possible but wondered if the potential
market would be big enough to warrant the cost.

Matt Roberds