There is always the problem with LV ones of the transformer going... usually
it's been tucked into the most ackward of places too.

For tons of data on the different LV and Mains Voltage lamps available then
check he
http://www.tlc-direct.co.uk/Technica...a/LampData.htm

"Andrew Gabriel" wrote in message
...
In article ,
"Rafal" writes:
Hi
Just had a look at some 240V halogen downlighters from B&Q.
I have noticed that the bulb or rather the reflector part of it has
diffrent color to LV 12V ones /240V clear , 12V slight colour shading/
Is there any noticable diffrence between them in terms of the light
output
per Watt.
and the light quality itself?

Both types are available in aluminium or dichroic reflectors.
(Actually, aluminium LV lamps have become difficult to find.)
Dichroic reflectors don't reflect the heat so the beam is
cooler, but the fitting has to be able to handle the extra
heat dumped backwards into it.

The type of reflector makes negligable difference to the light
output per watt, but the voltage difference certainly does.
The 12V lamps are significantly more efficient than 240V ones.
Also, because 12V lamps can be built with much smaller filaments,
it is possible to control the light distribution much more
accurately than with 240V ones, and you'll find a wider range of
beam angles available, with the optics also able to better
control light spill outside the intended beam.

--
Andrew Gabriel