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ArcticMyst Security by Avery

Low power IR laser driver. Help please

Joined
Mar 19, 2015
Messages
1
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hi guys I would really appreciate some help. I am new to working with lasers and fairly new to electronics. I have read the stickies and done some searching on here but i am still a little confused and most projects/threads seem to be dealing with much higher power lasers.

My aim is not necessarily to get just to get the job done but also to understand it better.

My project is as follows. My DIY night vision scope (using p8079hp) is very sensitive to IR light and I need to power down my ir laser diode.

I have a 780nm 3 to 5mw ir laser module, link 780nm 5mW Infrared IR Laser DOT Module 3VDC 6.5*10mm-in Laser Equipment Parts from Industry & Business on Aliexpress.com | Alibaba Group

It’s drawing around 100ma (so it says). This fits the application housing perfectly.

Is there a way of reducing the power as it is electronically (not using neutral density filters)?

From what i have read i can’t simply reduce the voltage.

Do I need to disconnect the driver that comes with it and then use a linear regulator such as lm317 (or a LM1117, or LM1084) as shown in this tutorial and elsewhere on this forum and stickies. link, https://www.youtube.com/watch?v=2Rjlf7gnXms&index=1&list=FLvDz5qg306cBYqSTj0diLhw ?

Am I right in thinking to maintain the current power of 100ma I would need to use a 12ohm resistor? and to reduce its power by half what size resistor would I need and how is this calculated? Ideally I would like it to be around 1mw output to make it as safe as possible and so that it doesn’t burn my intensifier tube.

or would something like this be the answer, link NEW APC Drive for Laser Diode laser Module 650nm 780nm 850nm 405nm-in Laser Equipment Parts from Industry & Business on Aliexpress.com | Alibaba Group

In terms of power, I will be using 2x cr123a (3V) batteries producing 6V as this is required for other parts of the project (very defocused laser illuminator that requires 6v)

If the above is not suitable, if anyone can point me in the direction of a 1mw 850nm focusable laser module of the same size (6mm diameter) that would be great.

Many thanks in advance for any advice,

P.s the space I have to fit the components in is very small so the fewer components the better.
 





Joined
Aug 14, 2013
Messages
2,655
Points
63
I think those modules just use a simple
resistor, so reducing voltage will also
reduce the output. That driver looks like
it uses photodiode feedback, so it's
useless for these 5mW modules, as they do
not usually have a photodiode. Do you have
one you can cut off the black heatshrink
and take a couple pictures?
 




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