Andrew Gabriel wrote:
In article ,
doozer writes:

Tim Mitchell wrote:

In article , Martin Angove
writes


In message ,
"BigWallop" wrote:


"Andrew Gabriel" wrote in message
.uk...


I don't know what sort of lamp this is, but if it's a short
arc HID tube, it is started with a very high voltage pulse
(many 10's of kV) which is a safety risk. Also the bulb itself
is pressurised even when cold and will not just break, but
will explode if dropped or scratched, and you should be
wearing eye protection whilst handling it. If you damage it
in handling, it can also explode later when running (at even
higher pressure).


Andrew Gabriel


It is under pressure Andy, that's what the UHP stands for on the
lamp. It
is Argon gassed to quite a bit of pressure in fact.


Been there, done that. At the same place where we had all the video
projectors, we also had some theatre-type lamps. The Mac2000s (robotic
lights) had a very bright discharge lamp, but unlike the projectors,
they didn't have an automatic timer-based safety cut out. Result (before
I got into the habit of logging every bulb change) was that a bulb
exploded inside one of the projectors, destroying the ceramic
lampholder, rear reflector and (inch-thick) front lens. Bits of glass
got into the rest of the projector and caused damage to servos, wiring
and electronics. You can imagine the repair cost in parts alone.

The other thing to note with these type of lamps, and with other high
temperature lamps which often have quartz-glass, is not to get
fingerprints on the bulb. I hate to think of the mechanism, but it seems
to soften the glass around the grease mark, causing the envelope to
bulge and thin and eventually break.


It just creates a hot spot because some of the light is absorbed by the
fingerprint. If a lamp does get touched you can clean off the
fingerprint with an alcohol wipe (before firing it up!) to prevent any
problems.

Regarding the original question and having looked at the pictures, the
reflector, lamp and housing look like a custom part. I don't think you
would be able to get the lamp bit separately. Have you tried googling
for the lamp code?

Thanks for the warning about explosions and finger prints. I knew about
both but I didn't realize they exploded with quite that much force. I
will handle it with more care from now on.

If it helps, and someone else asked, I have included a picture of the
front of the bulb here

http://www.crazysquirrel.com/images/bulb/front.jpg

if nothing else I would be interested to know what type of bulb it is.


Now you've posted that, not so sure it's a short arc lamp,
as the arc tube would be expected to have a spherical bulge in
the middle, which I can't see. It may be just a metal halide
lamp, or HMI lamp (probably too small, but no scale in you
photos), or if it didn't require any more than a second or two
warm-up time (before it died), a xenon lamp.


It comes on just about straight away and then takes maybe 30 seconds to
get to full power. It's hard to take photos of something that is
mirrored hence the poor quality. Internally it is basically just two
wires that touch together. The bulb is about 75mm x 55mm although I
haven't taken it out of the housing so there is some error in that
measurement. There is certainly no spherical bulge in the middle the
face is perfectly flat.

--

.¸¸.·´¯`·.¸¸.·´¯`· Shallow Sea Aquatics .¸¸.·´¯`·.¸¸.·´¯`·
.¸¸.·´¯`·.¸¸.·´¯ http://www.shallowsea.com ¸.·´¯`·.¸¸.·´¯`