"Martin Angove" wrote in message
...


I don't know about the particular system in question, but a place I used
to work had two different versions of the same idea. Neither was
suitable (IMO) for domestic use other than perhaps task lighting or
effects and highlights.

The first system was used in shop display cabinets. A light box on top
of the cabinet fed fibre optics on the shelves in order to light the
goods on display. The system was designed for use with General Electric
20V 150W projector bulbs - "DDL" I think they were called - which had a
lifespan of something ridiculous like 220 hours. We eventually
discovered a 21V "EKE" bulb which lasted a lot longer. There was a
variation on this cabinet where the light source was underneath the
display and used bog standard 12V 50W bulbs, but it was only really for
highlighting and not much good for general illumination.

The second system used discharge bulb "projectors" and huge bundles of
fibre optics to light a pathway through a dark area. I suppose that if
you used more fibres at each point they would produce a reasonable
amount of light, but it seems a bit of overkill for something that could
easily be done another way. The projectors took a good 30 seconds to
start up in the morning too due to the need to strike and warm up the
discharge bulbs and if for some reason (power loss - happened quite a
lot) they went out, you had to wait at least 10 minutes, and often 15
before trying to relight them.

I can see two advantages to fibre optics: they are completely waterproof
(very advantageous in the second situation described above) and they
provide light without heat (at the delivery end). Other than that: they
are expensive, have low light output, and are difficult to control.

Now, I suspect that what I know of fibre optic lighting is not at all
like the system Bob or Norm was fitting (though the principles must
surely apply), but since these are the only systems I've met that's all
I can talk about :-)

Hwyl!

M.

They sound like similar systems - light box with (I think) 50w lamp fed out
on optics to outlets in the stairway / landing ceiling to provide "pools" of
light. Looked quite effective and the output end was adjustable to give
either a sharp "spot" or wider "wash". Only reservation is the thought of
plunging everything into darkness when the bulb fails (yes, I know bulbs are
for growing daffodils and I should have said lamp).
Richard