Found a local specialty headlamps warehouse locally, called
"Candlepower". They gave me some 14 pages of info on auto arc
headlights. I'll abstract here, and if anyone wants the info, I'll
copy and send it.
The OSRAM company in Munich Germany began development in 1987.
It was ready for mass production in 1991. It is a high pressure
gas discharge tube (read arc) based on Xenon and halogen gases. No
filament. They make plug in versions, parabolic reflector version,
ellipsoidal, and complex shape versions. The newest D2L lamp (L
stands for long life) lasts for approx. 6,000 hours (should outlast
the car). I saw one in their shop (all they had) but could not
touch it of course. I believe that to touch one is to ruin it.
It is 10 mm diameter, and 55 mm length on a 25 mm base.
The D2S model is made from "ultraviolet absorbing quartz," so that
plastics can be used for the diffuser plates (UV absorbing quartz?
I thought quartz was used especially because it passed UV. ? ).
They draw 35 watts, and put out twice the light of the tungsten
filament halide 65 watters. "The ZENARC gas discharge lamp
does not have a filament. Instead, an arc is created between two
tungsten electrodes, in an extremely small quartz bulb. The bulb
is filled with xenon gas and metallic salts. The lamp ignites when
high voltage is applied. The arc of ionized gases then heats the
quartz bulb to such high temperatures that the metallic salts
vaporize. Only when this metal vapor is present does the lamp
produce full light." "At 85 lumens per watt, the luminous
efficacy of the XENARC DS2 is more than three times higher than
that of an H1 halogen lamp."
RECOLLECTIONS: A so-called "ballast" is used. Obviously, a
ballast does not work on D.C. There is a stepped up, A.C. 25,000
volt igniter voltage generated (from the regular 12V supply).
There is also a supply of 85v +/- 20% for the arc itself. (To be
controlled by a ballast, this must be A.C.)
Bulbs cost around $120 each. Ballast about the same. Size of
ballast is about 2" X 2" X 3". Very compact. One ballast per
They were first used in the USA on the 1997 Lincoln Continental
Mark VII, as a $1000.00 option (as on any of the foreign cars).
Not much available right now. A conversion kit for older cars is
expected on the market in about a year.