In article ,
Tim Watts writes:

Nice... Where do you get the optics?

Rapid sell a selection, and CPC a few.
Mostly I have bought them from trade lighting shows (or
got free samples in some cases).

Farnell were advertising heavily at the last one I went to,
but I haven't yet got around to looking at what they have.
Thermal management (heatsink, and heat conduction) is even
more critical. Rapid stopped selling the heatsinks I often
use, so I will have to find another source shortly. The
other way, as above, is to conduct the heat away to the
luminare casing, particularly if it's aluminium or copper.
I tend to make copper strips to do this out of copper pipe
hammered flat. I did use some copper bus bar offcuts too,
but buying it new is much more expensive than using copper
pipe.

When designing fittings, I try to consider which ones are likely to
still be around in 10-20 years time. I like and have used 2D lamps
in a number of designs, but they don't meet the efficiency standards
required by the EU. However, it looks like manufacturers are now
addressing this with modifications to some of the 2D power ratings,
but other ratings will probably go away.

Is there any opinion on whether 28W will be a safe bet, or not?

16W and 28W look safe - GE have produced wattmizer versions.
10W and 21W don't look like they have a future, and I have used
both of these. I wouldn't use 10W nowadays in new designs as that's
right in ideal LED terratory now. Getting same light output as a
21W lamp in the same space and keeping it cool enough for LEDs is
still quite a challenge. (28W would be easier as the lamp is bigger,
and so will the fitting be - indeed LED versions of former 2D lights
already exist in the larger sizes.)

--
Andrew Gabriel
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