IR LASER Driver Project on Shooting Simulator.

[rtp3955]

Hi all, my name is Ta nice to be here. I have not been educated any engineer subjects. Actually is Im law enforcement agent.. So Im here because I hv a little project ab shooting simulator for all agent shooting exercise.

I have already spent almost 2 yrs for developing my project. First, is motion detection program which powered by senior computer engineer, was completed last jan, 2014. Second, is hard ware device which always failure because of reasons as follows:

1. Green laser is too big module which doesnt fit to the barrel of the gun
2. Red laser is good for its size which fit to the barrel completely, however, its beam is interfered by light circumstance (noise) that the webcam cant detect the spot.

So I decided to try IR laser and mod my webcam to ir webcam.

Last week, I ordered IR 808nm 100mW 5.6mm TO-18 from China. I would like to seek all of you for kind assisting me " HOW TO BUILD/BUY THE SUITABLE IR LASER FOR MY PROJECT"

My requests are very simple as follows:
1. Use IR 808nm 100mW 5.6mm TO-18
spec


2. Use battery A27 12V. 20mAh X 1 cell or any recommend small battery as AG3 x 3 cells Please educated me
3. Need Round Circuit Driver with APC, diameter 8.5mm, supporting IR laser through 3 holes socket.

These are Pics design by Google sketchup
1) Top view



2) Bottom view



I want it to beam 10-20 meters. No need high power to burn anything just beam ahead and the light intense enough to detect by the IR webcam. I request for simple IR laser driver consume input DC 12 V. (round with 3 holes socket) which is stabilize beam and small enough to fit to the my barrel (8.5mm). Could you please suggest me where can I buy it or how to build one.

Thank you for your kind attention and your prompt reply (whoever can help) will be greatly appreciated.

Best Regards,
Ta

PS. this is an innovation project so I dont wanna buy one like "laserlyte" or any similar products, wish you understand me.

Email: udom_ta@hotmail.com

 

[Sigurthr]

Hello, Ta.

Just want to inform you that this laser diode can cause permanent irreversible eye damage and lead to blindness despite the fact that the spot and beam are nearly invisible. I'm not saying you cannot use this diode for your purpose, but you need to equip all participants and bystanders with appropriately rated and certified laser protection glasses for 808nm.

I'm sure that if you promise to do so then others here will help with your project. If not, then I doubt anyone will help due to negligence.

Best of luck!

 

[rtp3955]

Dear Sigurthr,

Thank you for your kind attention and useful comment. First, I realize the biggest problem ab class 3b IR laser, 100mW and will discipline instruction that you gave to me. However, I will experiment this device with this methods:

1 Make the filter like X-ray film put in front of diode and will see how intense that acceptable (web cam detect)
2 Looking for IR eyes protect glasses (quite expensive)

and would like to seek your opinions how these effect to participants if?

1 The IR beam not directly to the eyes only dot on the screen which 5-10 meters away??
2 The IR beam dot is very small, might be max 5 mm dia on .5 sec per once??

If above matters may effect and harmful i will abandon this IR 100mW diode and head to another Laser Diode. By the way, I need your help How can I lower the 100mW to 5mW? Please enlighten me. And this the 5mW I found on ebay:

http://www.ebay.com/itm/10pcs-TO18-...R-Laser-Diode-LD-ROHM-RLD78MYA1-/110996644537

Is it work?????

Thank you again, Sirs.

BRG
Ta

 

[BShanahan14rulz]

100mW is the maximum optical power that the manufacturer is claiming that diode can output. If you feed it less current, though, it will put out less light. And it being 100mW max is a good indication that it can probably go down to low powers and still lase.

If what you are trying to achieve can be done with <5mW (ideally, <1mW) of output, then it's best to use the least amount of power necessary. 100mW can damage eyes very easily, and you never can be sure that the device will never ever be pointed at someone's eyes or at some specularly reflective surface that might cause a beam to reflect into someone's eyes, etc.

It's easier to control laser output by varying the current, rather than varying the voltage. You might could just hook it up to a decently filtered lab power supply in CC mode and just crank it up until you can see the dot on camera. I don't know how successful people have been running bare diodes off of lab power suppplies, and I don't know how noisy the outputs on those power supplies is, but that's the basic idea you would follow, even if you have to use a driver. You'd just adjust the driver, test, can you see it? If not, turn up the current a bit and repeat.

One point that I'm a bit confused on, will the IR camera be looking downrange, the same direction that the laser will be pointed, or will the laser be pointed at the camera? If the latter, then you could potentially go with even lower power.

Regarding your sketchups, do keep in mind that the light emitted from the end of the laser diode is not a laser beam. It is a divergent cone of light. You will need an external lens to focus the diode.

I should have googled before I typed all this. What about something like this ebay item:
2X 3VDC 3mW 780nm Infrared IR Laser Dot Module 6 5x10mm Mini Type | eBay

6.5mm diameter, lens already installed, looks like it already has driver, and you just supply it 3V from a source capable of 10mA.

Note: that is just a random ebay item, I don't know if seller is reputable, or if that item is what the auction says it is. Just an example to show that there are items out there that may make your project easier for you.

 

[The Lightning Stalker]

This is the wrong diode for this application. If you look at the divergence angles, 35° is unacceptable. At
any distance, it will form a line instead of a dot. It looks like a multimode diode. Single mode is the
thing to be looking for here.

Also, an 8.5mm round driver board is not currently available. You will have to build your own board. I
recommend the LM1117 SOT-223 surface mount. The circuit would be similar to the DDL driver, except
substitute the LM1117 in place of the LM317. Always discharge the capacitor before connecting a
diode.

 

[rtp3955]

Thank you for your valuable suggestions and concerns. I will bring these to apply my project.

@ BShanahan14rulz
1 laser will point to the wall head the same direction of the camera.




2 I designed the external lens already.



and Thank you for your kind assistance to find me the best IR laser, it could work

@ The Lightning Stalker
Thank you for your suggestion ab my nothing IR laser... Haha I guest I hv to dump this lot to the trash. However, I hv to rethink ab the instant IR laser as BShanahan14rulz recommended and.... thank for the LM1117 SOT-223 but as I said I am not the engineer,, may be hv to find someone do it for me...

Thank you both of you.

BRG
Ta

 

[Sigurthr]

As stated above; the danger lies in the possibility of reflections off of surfaces and accidental alignment of the beam with someone's eyes. Unfortunately, that means that appropriate glasses (about $60 on average) are completely necessary when using an output power of over 5mW.

There is another way to accomplish what you wish without the use of high power lasers or requiring expensive protection goggles, but it will only work indoors:

1) Use a confirmed 5mW red laser
2) fit the camera with a red pass filter that blocks blue and green light.
3) light the area with blue or green (or both) only light from a lamp with a blue or green stage lighting color filter. The camera will pick up very little of the blue/green light and the spot from the red laser will be very bright in comparison; easy for the camera to see.

This has several advantages over using IR;
1) it will be eye safe.
2) it is easier to aim since the user can see the laser spot
3) it is far less expensive and easier to source parts. There are complete 5mW micro red modules available for only a couple dollars. Any stage lighting store will have the red and blue/green filters needed. Any webcam will work.

 

[rtp3955]

@ Sigurthr

Your IDEAS are pretty well solutions!! I agree to test my camera in that circumstance. You right! my problems might not be the Laser but the webcam. However, I will try any ways that could work.... I dont wann dump my 2 yrs project and I accept all of your concerns ab IR 3b class.

Thank you very much

BRG
Ta

PS. I found one on ebay. Could you pls check it specification for me that safe enough.

http://www.ebay.com/itm/5pcs-3VDC-7..._DefaultDomain_0&hash=item4611ef0a12#shpCntId

Thank you.

 

[BShanahan14rulz]

The specifications look right to me.

A note about your battery, it is a 12V battery, but your laser will not require this much voltage. You could go with 3 stacked button cells to power this module. In this case, probably LR41 cells. Make sure to get Alkaline, not silver oxide and not zinc air. The 12V battery you linked might actually be a stack of 8x 1.5V button cells.

This wiki page is good for to reference the battery size, since you want to make sure it fits and that you have room for wires too: List of battery sizes - Wikipedia, the free encyclopedia

If you already have the 12V battery, you might be able to disassemble it for the button cells. On this site they show an A23 which is too big for your application, but A27 is likely similar but just smaller:
12 Volt Battery Hack! You'll be Surprised...

 

[Sigurthr]

Yep that module looks safe, keep in mind then you'll need a harder to find NIR Pass Filter for the camera, and even then you'll probably want to use fluorescent lighting in the area as other forms of light have too much NIR and may obscure the dot.

 

[rtp3955]

Copy That! Thanks a lot.