Using lasers to deter burglars

[uscpsycho]

I have an idea for using lasers to make burglars uncomfortable should they break into my home. Or distract them enough to make it hard to rummage through a room. And of course, I don't want to do any ocular damage. But I have no idea how to effectively do this.

My first thought was to buy a DJ laser device that throws lasers all over the room. Amazon has lots of options and some are under $100. Would something like that be effective? Are there certain power specs I would want to get?

Then I read about laser dazzlers which are designed for deterring people, but they seem to be handheld devices which won't do what I want. Then I discovered bird lasers like this - https://bird-x.com/bird-products/indoor-laser which looks like it would work but it's expensive and probably overkill. I could spend hours and hours going down the rabbit hole when the answer is probably super simple to someone who knows the field. So here I am.

The main thing is that the device needs to be powered by an AC plug so that I can turn it on/off with a smart switch. It also needs to have a "hard" switch so it automatically turns on when it is plugged in. Not a device that requires you to press a button after being plugged in.

Can anyone offer some suggestions?

EDIT: That bird laser linked above is sold for about $100 less from some stores. I found this in their instruction manual (https://bird-x.com/wp-content/upload...RUCTIONS.pdf):
This laser is Class I. The power of each laser point is no more than 1 milliwatt,which is not harmful to the human body or eye. Sounds good but then it has the following precautions.
 Never look directly into laser beams, or into the specular reflection(s) of any beam.
 Wear safety goggles to protect your eyes when necessary. DO NOT point towards other people.
 Mount at or above a height of 3 meters. Project beams above eye level.
 Do not project beams onto specular (reflective) material – for example, mirrors.
 Do not project beams at room entrances.

So what's the deal? Safe or not? And would it be an effective deterrent in the way I want it to be?

[VDX]

... better use a DLP-beamer - no laser-hazard and you can easily either simulate "laser-beams" oder some weird, hypnotic animations

Viktor

[uscpsycho]

... better use a DLP-beamer - no laser-hazard and you can easily either simulate "laser-beams" oder some weird, hypnotic animations

Viktor

Can you share an example of what you are talking about? I did a search for DLP beamer and did not find much.

There was one item on Amazon for $3,000+ https://www.amazon.com/Projector-Por.../dp/B0CPCY6YQV

And what do you mean by hypnotic animations? I'm not trying to display any actual images, just trying to create a disorienting lights.

[buffo]

I think his point was that you can use a bright DLP video projector to safely startle and disorient an intruder while also using it as a video projector to display whatever video effects you might enjoy. Although to be effective, the DLP projector would have to be powered up all the time. Not sure how long it would last...

Using a laser to dazzle or disorient an intruder is possible in theory, but it's a terrible idea in practice. Getting the power level high enough to distract someone, without causing permanent eye injury, is going to be *very* tricky. For sure you will need to be above the MPE to have any meaningful effect, but that immediately qualifies as negligence. If you cause an injury, even to someone who is trespassing on your property, you can and will be held liable. It's very likely that this could also be classified as a booby-trap (because exposures above the MPE are the very definition of a known injury hazard), and booby-traps come with their own set of penalties.

The best defense against an intruder is honestly a dog (doesn't need to be mean - just needs to bark loudly), or barring that, a motion sensor alarm that turns on a bunch of lights and triggers a horn.

Adam

[absolom7691]

What about a strobe? If set with a low and irregular cyclic rate that averages about 1 to 2 seconds per flash, that would destroy someone's sight in a dark room while also not letting them get a "lay of the land". The irregular cyclic rate also prevents them from anticipating each flash by closing their eyes. Use a xenon strobe, not an led one. Xenon strobes can dump their entire 20,000+ (depending on size) lumen output faster than the eye can physically blink. Strobes are also pretty disorienting, in general. There's also the added psychological aspect of burgaler knowing that you're aware of their presence. Maybe even them thinking that you're taking pictures of them. Might delay them long enough to be able to dial 911. Source credit: Rear Window.

[buffo]

That's an excellent point: A strobe is going to be far brighter, and thus much more disorienting, than a DLP projector ever could be.

In fact, didn't the government do some research on using super-bright strobes as a battlefield incapacitation weapon back in the 80's? Thinking this was something for the "urban battlefield", e.g. clearing buildings room by room, if my memory is correct. (Like a flash-bang grenade, only without the "bang" part.)

Regardless, I think it would be quite effective, just based on my personal experience with strobe lights over the years. Plus, a strobe will be much cheaper than a projector.

Adam

[absolom7691]

Not sure if I knew that about the study of strobe effects. I may need to look that up.

I think my estimates of 20,000 lumens is probably pretty low. I guess it really depends on how big a strobe is that's used. My Adj mega flashes use 120,000 lumen lamps. Whether or not they hit that output is anyone's guess but it's probably over 100k. Megas flashes are only a few hundred bucks, too. Way cheaper than a DLP for output intensity some smaller 300w or 400w strobes would probably be in the 30K or 40K lumen range.

Thank ending scene in Rear Window made me think about the possible application here.

[kecked]

Not sure if I knew that about the study of strobe effects. I may need to look that up.

I think my estimates of 20,000 lumens is probably pretty low. I guess it really depends on how big a strobe is that's used. My Adj mega flashes use 120,000 lumen lamps. Whether or not they hit that output is anyone's guess but it's probably over 100k. Megas flashes are only a few hundred bucks, too. Way cheaper than a DLP for output intensity some smaller 300w or 400w strobes would probably be in the 30K or 40K lumen range.

Thank ending scene in Rear Window made me think about the possible application here.

ithunk a microwave magnetron aimed in their general direction would be most effective and you’ll have lunch when you get home.

[VDX]

... this could be achieved with a MASER at some Kilowatts averaged power, but not with a microwave magnetron, as salvaged from the kitchen, as its missing the reflective housing to generate/resonate standing waves

[kecked]

... this could be achieved with a MASER at some Kilowatts averaged power, but not with a microwave magnetron, as salvaged from the kitchen, as its missing the reflective housing to generate/resonate standing waves

the idea is to say just enough to be funny but not enough for them to hurt themselves or others…..