Suggestions needed for a high power IR LED or IR laser diode
ElectricAye
Posts: 4,561
Hi all,
I would like to reduce some of the light pollution that plagues the area where some of my friends want to do some star gazing. The only problem with the area they have selected is an annoying lamp on a tall post that seems to be controlled by a light sensor (the light will come on during the day if a dark storm passes over). So I'm guessing that a high powered infrared LED aimed somewhere near the light will cause it to go out when desirable. Or perhaps an IR laser diode would be better. But I don't have any knowledge of either LEDs or laser diodes. How much power would I probably need from, say, 20 to 30 meters (60-90 feet)? What sort of characteristics would probably do the job? I don't have enough knowledge to even guess at this point. Suggestions or comments would be greatly appreciated.
thanks,
Mark
I would like to reduce some of the light pollution that plagues the area where some of my friends want to do some star gazing. The only problem with the area they have selected is an annoying lamp on a tall post that seems to be controlled by a light sensor (the light will come on during the day if a dark storm passes over). So I'm guessing that a high powered infrared LED aimed somewhere near the light will cause it to go out when desirable. Or perhaps an IR laser diode would be better. But I don't have any knowledge of either LEDs or laser diodes. How much power would I probably need from, say, 20 to 30 meters (60-90 feet)? What sort of characteristics would probably do the job? I don't have enough knowledge to even guess at this point. Suggestions or comments would be greatly appreciated.
thanks,
Mark
Comments
-Phil
To PhiPi.... That filter thing is a good idea, but, alas, this "party" would be not just for eyeballs adorned with telescopes: this star gazing event would be for naked eyeballs as well, so they'll probably not want me to tape astronomical filters to their eyebrows for very long and kill the romance of the moment. So it looks like I'm stuck with the "laser pointer" option, at least for now.
I have heard, however, that there might be some danger of a laser pointer permanently sizzling such a sensor. Anybody have any ideas/feelings/opinions on that possibility? To be safe, I suppose I can disperse the light a little, but I was just wondering if anybody might really know if that could happen. Despite all the evil that lurks in the marrow of my bones toward needless outdoor lights, I wouldn't want to damage somebody's property.
Much.
Why such a distance? surely you can get closer. How about a powerful beam light , a tripod (for height and stability) and a mirror. Just use the mirror to beam the light where you want it.
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Aka: CosmicBob
To Mike.... Yours is a very good point about the eye safety issue. I have no intentions of using a "high power" laser: I was thinking along the lines of a typical laser pointer (like what you get with a pen) - is that considered high power??? I guess they do have a little warning sticker on them. I'm guessing a high powered IR LED would be a lot safer for everyone and everything. And it wouldn't freak out any airplanes flying over - as much - I hope. I suppose if I did have to use a laser, I could mount it on a tripod that extends above eye level so people are less likely to loiter in front of its beam and unknowingly incinerate their rods.
To SRLM.... an arbor vine. Yes, I like that idea. A splendid idea. You must have read my posting on the Astronomer-GardeningForum.com where nerds like me post their vegetational solutions to problems concerning astrophysics and gravitational lettuce head imaging. But I was hoping to make friends and influence enemies by simply flicking a switch and magically cause that annoying light to wink out. That's not as easy to do with a potted plant or a pop-up trellis.
To Bob Lawrence.... The mirror idea sounds cool, especially as a kind of reverse telescope concept. The distance is necessary because the lamp happens to be across a road on the property of somebody else, who is almost never around. I feel intrusive if I'm mechanically in their space or shining a visible light at their junk.
Thanks everyone for chiming in on this,
Mark
SRLM.... I think you've been reading my subconscious mind.
Dave
Ha! Wrong, the laser has been discussed. It doesn't get any faster than the speed of light! :}
Heaven forbid, that just wouldn't be PROP-er.
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It might be the Information Age but the Eon of Ignorance has yet to end.
Sounds like a plan, but with my luck I'd hit the sensor and the dang thing would be alit both night AND day.
It might be tough explaining what kind of bird poops slightly skyward at high velocity, though. But, you know, once upon a time people used to believe in banking systems and stock markets, so I guess gullible is a style that is often the fashion.
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you can get natural light LEDs these days (i.e. close to sunlight)
trail the leads down the post to above head height with some kind of waterproof connector at its end and then just plug in power when you need to quench the offending light source.
Dave