Rick Blaine wrote:
Bud-- wrote:

I assume zenon is arc-discharge like flourescent, neon, high pressure
sodium,... It would then need a ballast for whatever supply. Not obvious
why they would have 12V supply unless it works on DC and can be used in RVs.

The Zenon hockey pucks I installed in my kitchen looked identical to halogens
and did not have a transformer or ballast. While they may be cooler than
halogens, they certainly generated a fair amount of heat on the high setting.
Enough that you could feel a warm base shelf above the light. I think most of
the improved safety in Zenons comes from the vented design of the light fixture
and not the type of gas.


Xenon lights I have read about before were arc–discharge, like
commercial motion picture projectors and headlights.

Looking up some information - these are incandescents with a xenon gas
fill. The xenon transmits heat more poorly than other gases likely to be
used, increasing the efficiency. The xenon also impedes evaporation of
the filament, so the filament can run hotter which gives a bluer light
like halogen. Efficiency and life are higher than normal incandescent
but are not necessarily better than halogen. Bulb glass temperature is
likely lower than halogen, but if the efficiency is the same, they
produce the same amount of heat for the same wattage bulb. Flourescent
is much more efficient.

Bulbs for hockey puck fixtures look like they are all 12V. They then
need a power supply.

Better answers could be provided if there was a link to a fixture
source. But maybe not - information from sources I looked at was minimal.
Some fixtures are hard-wired, some connected with low-voltage wire
(fewer restrictions), some have a cord that plugs into a receptacle and
some have a plug-in transformer with a cord connecting to the fixture
Putting the power supply in the fixture makes the unit self contained.
A remote power supply may run several fixtures, but that doesn’t look
common.
If the power supply is a transformer, it may hum and a remote location
may be quieter. If it uses a switch-mode power supply it may be not
dimmable or require a special dimmer.

Don’t know how far that goes in answering your questions.

--
bud--