In article ,
"vortex2" writes:
Hi,

The 500W halogen light on my drive has just failed for the nth time.

I'd like to save some energy and lamp costs by replacing with a sodium light
of some kind (ideally with a dusk sensor), and on a timer.

Problem is that all the sodium lights I can find are ugly, looking more
appropriate to prison perimeter security or perhaps use on offshore oil
installations.

Example:

http://www.screwfix.com/app/sfd/cat/...12178&ts=07854

...unless anybody knows better. Any suggestions?

You could use a luminare (fitting) for an ordinary lamp, and
mount the control gear remotely. The easiest way to get all
the bits is probably to buy a luminare like the one you
identified, and then butcher it for parts. If you go this
route, keep the cable between the control gear and the lamp
as short as possible, and beware high voltage pulses are
used to start these lamps (long cable dulls the high voltage
pulse and can cause RFI). Go for a luminare rated in excess
of the power consumption of the lamp (at least 100W, and
preferably 150W) as the sodium lamp will prefer running a
bit cooler than a filament lamp. Any reflectors in the
luminare for use with high pressure discharge lamps must be
of the specular type (as shown in that Screwfix picture),
and not plain polished which can cause arc tubes to overheat
if it reflects the heat back onto them (which is the exact
opposite of what you ideally want for a halogen lamp).

Oh, and these lamps are only suitable for timed and/or dusk
to dawn operation, not PIR (movement) sensors.

--
Andrew Gabriel