On 6 Apr, 14:22, "Rick Hughes"
wrote:
"Adam Aglionby" wrote in message

...
On 6 Apr, 10:39, "Rick Hughes"
wrote:



"JA" wrote in message

...

I notice that on the Screwfix website some of the mains voltage GU10
halogen lamps are described as having a "dichroic reflector". Does anyone
know what "dichroic reflector" means in this context? I had assumed the
term dichroic just applies to lamps with the GZ10 style cap which direct
any heat towards the back of the lamp, as opposed to lamps with the GU10
style caps which direct any heat towards the front of the lamp. Now
seeing
GU10 halogen lamps described as having a dichroic reflector has confused
me
somewhat.

Dichroic lamps allow some of heat to pass backwards .. often used in lamps
which would put too much heat on object or person it was illuminating (eg
PAR 38 spots)

I had opposite requirement I wanted non-dichroic lamps for my Low-Voltage
down lights as I do no want the heat pushed back into housing .... they
over
heat & trip transformer.

Aluminised LV MR16 are very rare, no idea why, mebbe remote the
transformer?

No problem getting them - I simply order mine from 'Lightbulbs-direct.com'

My issue is that house is very well insulated, so no heat escapes upwards
.... and even with t/f *200mm away they still overheated if on for an hour
or more.

Remote wound trafos, but copper cost can get excessive.


Changed to Phillips Aluminum reflectors (Phillips Pro Alu) and no problem
since .. heat goes out through front of lamp rather than through rear.

Hadn`t encountered them before thanks:

http://www.voltimum.co.uk/news/422/s...uminaires.html

Cheers
Adam