First off, here's my idea that I'm working on:
1) Mount parallel IR and red lasers on a pan-tilt camera.
2) Using an Ultimarc Aimtrak (A USB gun that detects IR dots, similar to a Wii remote) create a shooting gallery where you try to shoot at the moving dot.
I figured that as long as the IR laser is below 5mw, and has a parallel red laser to help prevent inadvertent staring into the beam, this sort of thing would be OK, though I'd welcome input telling me otherwise.
I bought two of these:
3mW 780nm 6.5mm 3VDC Infrared IR Laser Diode Module PCB | eBay
...and one set (two) of these:
2pcs 6*10mm 650nm/660nm 5mW Red Laser dot Diode Modules
They both work as expected, creating either a bright red or a very faint (but visible) red dot on the far wall.
However, the IR dot isn't bright enough for the gun. The gun can only reliably pick it up out to about six feet, though it can unreliably see it out to about 12 feet. To shoot at a far wall, I'd want it to work reasonably reliably out to about 20 feet. Thanks to our friend the inverse square law, to bump 6 feet up to 20, I'd need to take that 3mw IR laser and bump it up to about 30mw. More IR than I feel safe having fly around my living room.
I did a bit more research, and found something interesting. When hooked up to 4.5V, the 3mw IR diode pulls about 4mA - putting its power draw at 18mw. I've heard numbers like 20% efficiency for lasers, so that sounds plausible. Meanwhile the 5mw red diode pulls about 16ma - putting its power draw at about 72mA.
I tried changing the filter on the gun to a red filter and using the red laser dot - I got performance very similar to the IR diode.
So, there are my facts, here are my questions:
1) Is it safe to have a 5mw IR laser bouncing around in my room, especially if it's parallel to a similarly-powered red laser? Would it be safe to go higher?
2) Which best explains the power draw discrepancy: a) IR diodes are much more efficient than red diodes. b) One of the diodes is performing far outside its specs. If it's (b), which one is it more likely to be?
3) What's a good, more reliable place than Chinese sellers on eBay (not that I had any problems with the two transactions that I did) to buy low-power IR laser diodes? Preferably one that doesn't go out of focus every time I move it?
4) Given that I want to just create a large moveable blob 10-20 feet away, what if I moved to several parallel <5mw IR beams? Any advice on setting that up? My attempts to make three beams (one red + 2 IR) parallel were laughable. If I kept them at least 1cm apart, it'd be difficult to get more than one in the eye at a time.
Thoughts? Suggestions?
1) Mount parallel IR and red lasers on a pan-tilt camera.
2) Using an Ultimarc Aimtrak (A USB gun that detects IR dots, similar to a Wii remote) create a shooting gallery where you try to shoot at the moving dot.
I figured that as long as the IR laser is below 5mw, and has a parallel red laser to help prevent inadvertent staring into the beam, this sort of thing would be OK, though I'd welcome input telling me otherwise.
I bought two of these:
3mW 780nm 6.5mm 3VDC Infrared IR Laser Diode Module PCB | eBay
...and one set (two) of these:
2pcs 6*10mm 650nm/660nm 5mW Red Laser dot Diode Modules
They both work as expected, creating either a bright red or a very faint (but visible) red dot on the far wall.
However, the IR dot isn't bright enough for the gun. The gun can only reliably pick it up out to about six feet, though it can unreliably see it out to about 12 feet. To shoot at a far wall, I'd want it to work reasonably reliably out to about 20 feet. Thanks to our friend the inverse square law, to bump 6 feet up to 20, I'd need to take that 3mw IR laser and bump it up to about 30mw. More IR than I feel safe having fly around my living room.
I did a bit more research, and found something interesting. When hooked up to 4.5V, the 3mw IR diode pulls about 4mA - putting its power draw at 18mw. I've heard numbers like 20% efficiency for lasers, so that sounds plausible. Meanwhile the 5mw red diode pulls about 16ma - putting its power draw at about 72mA.
I tried changing the filter on the gun to a red filter and using the red laser dot - I got performance very similar to the IR diode.
So, there are my facts, here are my questions:
1) Is it safe to have a 5mw IR laser bouncing around in my room, especially if it's parallel to a similarly-powered red laser? Would it be safe to go higher?
2) Which best explains the power draw discrepancy: a) IR diodes are much more efficient than red diodes. b) One of the diodes is performing far outside its specs. If it's (b), which one is it more likely to be?
3) What's a good, more reliable place than Chinese sellers on eBay (not that I had any problems with the two transactions that I did) to buy low-power IR laser diodes? Preferably one that doesn't go out of focus every time I move it?
4) Given that I want to just create a large moveable blob 10-20 feet away, what if I moved to several parallel <5mw IR beams? Any advice on setting that up? My attempts to make three beams (one red + 2 IR) parallel were laughable. If I kept them at least 1cm apart, it'd be difficult to get more than one in the eye at a time.
Thoughts? Suggestions?
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