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ArcticMyst Security by Avery

Need help with a speciffic laser

qavro

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Dec 7, 2013
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Hello guys,
After searching the whole internet (including the last 2 days spent here) i have decided to take a shot and register to ask for help.

Since i have several questions i will ask here about them because i hate to open multiple threads.

First and most important is about a BE Meyers laser. It is one that comes with it's own sealed driver, rather fat and big one compared with other drivers i've seen. The laser diode is a 12mm one with a very nice lens :) lol and it is of 200mW.

Based on my research, the 4 wires that came out from the driver are as i've figured:
Black (Ground )
Red (Positive +3-5V)
Green (no idea)
White (no idea)

White and Green where shrink-wrapped not to touch anything. After several head scratchings i decided that Red is + and Black is - and i have used as a tester a small lithium battery 3.7V/200mAh (sucking 299mA when powered) to play on the safe side.

To my total satisfaction the laser powered up perfectly to say the least.

After this introduction (to show you that i am not a total idiot) now comes my real problem. I need this laser to be powered down. I mean i need a way to control the output from near 0 to maximum 25% because as it is now it has no use for me. I already know that Meyers have some drivers pwm controlled and this one might be actually one of it, but how can i be sure? Is anyone here able to tell me what should i measure and how to figure if one of my 2 remaining wires is the actual pwm control? From what i've read these drivers can be pwm controlled from 4hz to 2Kz. If it is so, and i cannot (for some reason) use the remaining green/white wires, how can i control the output? Can i use a pwm module to power up the driver and that will reflect on the output from the diode as well? I think i can use a servo-tester used in RC for this?

My second question is optics related. I am sure that BE Meyers prices are mostly because of the optics. I am not saying the diodes are bad, but my money goes on the optics. The diode has a nice (rather big)coated lens in front of it, around 10mm diameter and of course is threaded and adjustable. The question is: that lens alone will allow me to make the spot wider (2-9 degrees) or i need another optical element in front of this to achive that?

When i did that with a chinese green laser, the output was a nice wider beam but was full of dark areas alternating with green light, like an old TV noise. It was because of the green laser, my added lens, or both?

When i will know all i need to know i will machine a case/housing for all the elements involved (have my own cnc, lathe, etc)

P.S. I know all i need to know about led illuminators, and have several of them to be able to say: i am not interested. Led illuminators are very good but simply not for what i need.

Thank you for your patience (i've wrote a lot but is better to explain than not to) and for any help/idea you might have.
 
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Joined
Sep 12, 2007
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We can better help you if we know what you're working on.

Your question about modulation would be better addressed to the organization from which you bought the laser. The standard is a 5V logic (TTL) for modulation on the other two wires, but you should check with them on the polarity.

the output was a nice wider beam but was full of dark areas alternating with green light, like an old TV noise.

You have to live with that. Physics insists it stays. This happens with all light to an extent, but it can be quite noticeable with laser light.

Yes, an adjustable collimating lens will allow adjustment of the spot diameter.
 

qavro

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Dec 7, 2013
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Thank you for your help Cyparagon.
About your first question: i want to make an illuminator adjustable in both power and beam spread.

About my first problem, i've asked. No luck yet with an answer, maybe i will get lucky later.

About the second one: i can and i will live with that once i get closer to what other laser illuminators do. i have seen attila, peq variants, civl to name a few and none of the experience speckles on wider beam. even the cheap pulsar one have a clear spot. of course, speckles might be there but if unnoticeable will not bother me. maybe some sort of diffuser will work?


PICT0324.jpg
 
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