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Little help needed

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Hi everyone,

Im after some advice and help...

My name Danny and I am currently a final year Product Design student at University of Brighton. For my final year project Im looking into a solution to help prevent/reduce accidents at festivals, towards festival goers. In the poorly lit sections around the festival.

I came up with using a laser suspended 12ft up in the trees or suitable platform, to project a grid pattern onto the ground below. In order to highlight potential obstacles. Similar to....

Lumigrids: Do you think cyclists are stupid? | thatsflawesome.com

But ofc better than this as its just full of so many flaws!

Anyway, I've been currently using two cheap eBay laser pen that come with pattern caps, one of which can produce a series of lines so by having two I could produce a grid like pattern for a prototype.

5in1 Green 5mW Laser Pointer Pen! Hi-Power! Club/Disco/Rave Lights! 5 Star Cap | eBay

Screen Shot 2015-02-12 at 05.29.23 by dannyhughes, on Flickr

No I know the theory works I want to make a fully working final prototype using one laser to project a grid pattern. So this were you guys come in I have limited knowledge on laser so sorry for all questions...

Ok so the laser itself needs to eye safe and in red, I know you can get specific eye safe lasers but from the company I spoke to they wanted £200 so wasn't within my budget just for a model, So wondering which rating and what sort of laser would be safe to use and suitable for being on for long periods of time?

Its going to be a self contained unit that houses the laser and I assume some sort of transformer? so that it can runs from the mains supply at a festival?

Now for the grid pattern itself I have been looking into diffraction grids etc and ordered these:

Howie Glatter Holographic Attachment for Laser Collimator - Square Grid Pattern | eBay

GRID lens for AixiZ 12X30mm laser modules | eBay

but wondering if anyone else has an ideas on anything I could use to produce the same effect.


Any help appreciated

Danny
 
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Since this is basically a laser projection,
it would be logical to think that this
would fall under the category of a "laser
show", and applicable laws, however, this
may be a gray (grey?) area. At the very
least, the power density at eye level
should fall below the ten second ocular
hazard levels. The output power will
depend to some extent on how far off the
ground the units are mounted.

An alternative, but less laser option would
be to use LED rope lights.
 
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Since this is basically a laser projection,
it would be logical to think that this
would fall under the category of a "laser
show", and applicable laws, however, this
may be a gray (grey?) area. At the very
least, the power density at eye level
should fall below the ten second ocular
hazard levels. The output power will
depend to some extent on how far off the
ground the units are mounted.

An alternative, but less laser option would
be to use LED rope lights.

The unit will be mounted 12 foot in the air as thats the standard height the majority of the halogen lights used at festivals are mounted at. Unfortunately LED rope lights will in themselves become a trip hazards as well as being complicated to install round a festival so they have to be ruled out.
 
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Power density should not exceed 100µW/mm² -
1mW/mm², whatever is the the least you can
get away with depending on the lighting
conditions. It may even be less. I don't
know exactly what your laws are there.
 
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Hi all

Just wondering has anyone tried to power a laser from a mains supply? Im just wondering what parts are needed? and any how to's.

I'm needing to power a 1mW/mm² laser (as needs to be eye safe) from a mains power supply (240v) for my finally year project at uni.

Any help will be much appreciated
 
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Before someone else corrects me, I will
correct myself and say that the 1mW/mm²
figure was wrong and should actually have
been 1mW/cm². I'm sorry about that and
hope it does not cause too much
inconvenience on your part.

With that out of the way, all you need to
power your laser is a phone charger. I do
it all the time. Use the phone charger in
place of the battery cell(s). Instead of
cell(s) --> driver --> laser, it goes phone
charger --> driver --> laser. You need to
make sure your driver can handle the 5V or
whatever the phone charger puts out. It
may require a driver change.
 
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Would one of these be suitable (ofc in the right power as these are 5mw) it says it has an incased driver built in.

Adafruit Laser Diode - 5mW 650nm Red [ADA1054] | eBay

Also is there any other way of powering it other than having a phone charger as for the product I want it too look and function as if it was the real deal. I ideally want a straight forward mains cable that goes from the wall to the unit where as with a phone charger the cable out of the unit goes to a large box unit attached to the plug, if that makes any sense at all.
 
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Would one of these be suitable (ofc in the right power as these are 5mw) it says it has an incased driver built in.

Adafruit Laser Diode - 5mW 650nm Red [ADA1054] | eBay
Yes that will work. You just need 5VDC.

Also is there any other way of powering it other than having a phone charger as for the product I want it too look and function as if it was the real deal. I ideally want a straight forward mains cable that goes from the wall to the unit where as with a phone charger the cable out of the unit goes to a large box unit attached to the plug, if that makes any sense at all.
Phone chargers aren't very big. You need a
regulated 5VDC and there isn't a simpler or
more direct way to get it from the mains.
Go with a name brand charger like Motorola,
Nokia, Apple, LG, or something along those
lines to avoid the cheap knock-offs that
will kill diodes and present shock hazards,
etc.
 




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