Converting a 200W discharge lamp video projector to LED

On 2/10/2013 6:35 PM, Arfa Daily wrote:
**BTW: This is the torch I spoke of:

http://www.ozstock.com.au/8108/Super-FREE-Ozstock-Day--CREE-LED-Powered-Torch-with-Adjustable-Lens.html


You may find one locally. It's a bloody rip-snorter.

--
Trevor Wilson www.rageaudio.com.au

I'm glad it's "Plash resistant" and has a "Tactical switch". They
should be useful features ... ! :)
Click to expand...

**What are you going to do? Spelling is not what it once was. One of my
regular buyng sites is a very large Aussie retailer. It appears they
employ copywriters whose first language is not English.

Seriously though, it is a somewhat different design to ones that I've
seen previously, so may be a considerable improvement. It does seem to
be a technology that's evolving quite quickly.

Arfa
Click to expand...

**Indeed. Here is where I get the some really nifty torches:

http://dx.com/

A nice aspect of the site are the uncensored reviews of their products.
Delivery is slow, but free. This is an immensely impressive torch:

http://dx.com/p/ultrafire-th-t60-ha-ii-xm-lt60-5-mode-1200-lumen-white-led-flashlight-with-strap-1-x-18650-57007

It does us special LiIon batteries though. About 3 Bucks each. The
special charger is another 6 or 7 bucks.

These things are astonishingly good:

http://dx.com/p/12w-7000k-800-lumen-white-led-emitter-metal-strip-12-14v-80512

Almost twice as bright (measured with a light meter) as an 11 Watt T5
fluoro lamp. They must be glued to a small flat piece of aluminium heat
sink, but, even then, they are exceptionally compact. I've purchased
dozens of these. I cannot recommend them more highly. Awesome product.
My neighbour uses them in his camping trailer.

And here is the 100 Watt LED emitter I purchased:

http://dx.com/p/jr-100w-w-100w-9000lm-6500k-white-light-10-x-10-led-module-30-36v-173825

It requires a separately available 3 Amp, constant current source.
Easily replaces one of those 500 Watt halogen work lights.



--
Trevor Wilson www.rageaudio.com.au
 
Supplied in small numbers , the lenses are supplied pushed into the
mounts and again they don't say how to remove them without damage to the
lens.
First one bodged by placing over a couple of metal plates providing the
across-flats 12.9mm gap to then push down as detailed below. As stated
previously you lock the holder to the pcb in normal use, by pushing the
lens into the holder , so first they have to be separate.
Then with 1 free holder, place back-to-back castellation to castellation
over the next one. Place a flat piece of rubber into the slot part that
takes the LED (so not to damage the thin lens wall) and push down quite
hard with a rod, until the lens pops the 1mm into the precise recess of
the other holder. Remove the second holder by hand and then grip the
lens across the pre-existing mold marks and pull out from the first
holder with serrated edge pliers.
Well that is my method for Osram Golden Dragon lenses made by Polymer
Optics Ltd as supplied by RS
 
The focused 7 cell honeycomb lens came together well. Doing the maths
and having a wedge tapering to .3mm seemed ok but trying to adapt
plastic to those sorts of dimensions is not practical. Having to mould
my own mounts.
The 2700K LEDs are noticeably cream yellow colour to the eye and seem to
have supressed the blue peak, too much?
Relative intensity through a dicroic colourwheel
R 340
G 270
B 070
even the reflection off the blue filter, ie complement colour of yellow
, is noticeably brighter than the reflections off the R and G sections.
I was expecting to add 5mm red LEDs but looks as though it will have to
be blue ones. Won't know for sure until the video projector has a
reasonable block of time to get inside to mess about.
 
As my mouldings to fit LED to lens are egg-cup shapes , a 3 part mould
required, letting epoxy harden before running off 7 of them, so far so good.
I was impressed with just trying one LED at 1/4 power of 90mA (no
heatsinks yet) and 5 feet away , bright enough to read by just.
Add a lens at the correct position and a neat bright foot by foot
"pixel" , of the chip thrown on a screen 5 foot away, probably as bright
as the projector showing white (DLP losses unknown).
So 7 of them and 4 times as bright would illuminate a 5 x 4 foot screen
, with that brightness. If 50% loss in hte projector then add another
ring of 6 , room in the "funnel" reflector for them if required.
I wonder what a gobo type thing made of a matrix of single RGB LEDs ,
with lens arranged to throw foot x foot squares with 6 inch overlap ,
would look like if driven with graphical/animated "video" pulses
 
On 24/03/2014 07:10, gigo.blacklight@gmail.com wrote:
any more on this? any luck?
would love some pics to see the progress
Click to expand...

It had enough light for domestic use but not enough for more than 2m
diagonal. I got the 60 or so LEDs and lenses for a Mark 2 version but
have been inundated with other work. And as have repaired a number of
600x800 vid projs along the way, I'm not desparate to get the HD one
working. The use tends to be just for projecting bullet-point script anyway.
I assume you've seen the pics URL'd here. Single compound LED built
around a 5 inch ball valve float. Mark2 would be 19-1 built around small
christmas bauble as basis. The central lens not having an LED but used
to pass light from a similar cluster behind it which also has a cluster
behind it. As long as the light falls in the well of one of those lenses
then its collimated to about 3x3mm focus, ie within the light tunnel
entry aperture
 
On 24/03/2014 07:10, gigo.blacklight@gmail.com wrote:
any more on this? any luck?
would love some pics to see the progress
Click to expand...

I worked out how to arrange the 19 lenses over a much tighter radius
surface. Setting some lifted off the sherical surface a few mm, so not
as elegant looking cluster
 
pics etc on later thread, titled
Converting discharge lamp to multi-LED for video projector (maybe)
 
On Mon, 24 Mar 2014 00:49:00 -0700, N_Cook <diverse@tcp.co.uk> wrote:

..snip...
I assume you've seen the pics URL'd here. Single compound LED built
around a 5 inch ball valve float. Mark2 would be 19-1 built around small
christmas bauble as basis. The central lens not having an LED but used
to pass light from a similar cluster behind it which also has a cluster
behind it. As long as the light falls in the well of one of those lenses
then its collimated to about 3x3mm focus, ie within the light tunnel
entry aperture
Click to expand...

just saw this thread. back in the 70's while visiting Varian in Palo Alto,
CA I met the inventor of the xenon arc light. He was looking for other
applications than 'tank' lights for this formidable light producer. He had
mounted it inside a 16mm projector to replace the 'hot' bulb presently
used. The projector spread the movie images over a 20 ft wide screen in
the brightly lit lab, yet the film was easily viewable in that light! and
the blues were incredible. and you could freeze frame WITHOUT burning a
hole in the film.

That arc light is also used in medical applications down tubes for
lighting endoscopy, etc. and in microscope platforms.

I think the arc light is available commercially at several places,
incuding those outlets like Edmund Scientific. It's a small cylinder with
ring contacts on front and back. I have one somewhere it's approx 1.5 inch
long by 1 1/4 diameter has a builtin reflector for throwing the light
forward. From memory the arc, once fired runs on something like 10A at
12Vdc, or so. But the light can be used on your off road vehicle to see a
mile ahead [again from memory] and having no filament, quite robust.

Not so much to distract your efforts, but worth looking at. Oh, one down
side. The light is so bright it creates ozone across the surface of the
bulb. and ozone and the aluminum parts in the projector didn't get along
so well. But still alternatives to think about.
 
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