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Hi Cliff,
Thanks for the video, sorry I missed you in N.Z. will catch you next time round.
Why not oil fill the light & fit plastic tube
over the wire & the fitting protruding out the back.
The plastic tube will squash under pressure &
equalize the light.
I've been playing round with & researching LED
lights. Have some photos of a modification
Have moved on from these lights as they run off 4
volts & you can't put 3 in series to run off 12V.
Also I used one while swimming through a cave &
it let a bit of water in despite it's O rings.
Have ordered & are waiting on this item, a 900
lumen 12V dive light $78-
I will modify & fill with oil as per my
first link.
The LED itself can take pressure down to full ocean
depth.
There are good articles on LED underwater lights on
the "Deep Sea Power & light" site.
Regards Alan
----- Original Message -----
Sent: Tuesday, January 17, 2012 1:54
PM
Subject: RE: [PSUBS-MAILIST] SeaBlaze3
LED bench test
Psub postings have been a bit
slow so I have decided to post a short test I did today on an off the shelf
LED light. Subsea lights are very expensive for psub applications so I was looking to see what kind of
depth performance I could get with an off-the-shelf LED marine light for
pleasure boats. I chose to test
the Lumitec SeaBlaze3.
See the YouTube clip of the test
at http://youtu.be/WXYPjIgoxLE . Prior
to the test, I took it to swimming pool to see how it worked at night. The
light worked great and very bright.
You could see across a an Olympic sized swimming pool without any
problem with just one of these lights.
The application I am contemplating would use seven of these lights
working off 24 VDC. The lights will work on 10-30 VDC.
For 24 VDC, they pull 1.1
amps. To conduct the test, I built a pressure
chamber out of 4 inch, schedule 40 galvanized pipe fittings. I then made up a
simple electrical penetrator using a ¾
inch pipe fitting, nails and some two-part epoxy. To pressurize the test chamber, I used
my pressure washer with a bypass valve.
To determine when the unit failed, I connected the light through the DC
current section of my multimeter.
Because the line pressure for my house during the test was 74 psig, this is the minimum pressure point for
the test.
Results were that the LED light worked fine for about 4 minutes at 74
psig or 167 fsw. At
that point, the case flooded. The
application I am looking at has a 500 fsw design depth with a max test depth of 625 fsw.
Therefore out of the box these would not work but it would be straight
forward to pull the electronics and LEDS and insert them in a custom 1-atm shell. This lights was $220.
The
reason I thought this had a chance of handling the pressure was because the
case is anodized aluminum and the lens is glass. The LED
face plate was in contact with the lens so structurally it was being
supported. My guess is that they must have used some kind of adhesive to seal the lens rather than an
o-ring. My next step is to tear the fixture apart and see if the
electronics and LED could be repackaged for pressure.
Cliff
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