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Smaller version of Bedazzler?
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Please be positive and constructive with your questions and comments.

Smaller version of Bedazzler?

by Tolgaozuygur on Mon Nov 29, 2010 1:26 pm

Hi there,

I will be building a bedazzler. but I was wondering, if anyone tried to build a smaller (one small enough to carry around daily) version of it?
Of course I can guess if its possible, the effective range should decrease, which is not a problem on my perspective. Since the original one is designed for UK police force to perform crowd control (If I'm not wrong), a smaller version would be more suitable for an individual as a non violent self-defense tool, with a shorter range.
Even if no one built one yet, all suggestions and comments are welcome.
Tolgaozuygur
 
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Re: Smaller version of Bedazzler?

by tinsmith on Mon Nov 29, 2010 2:46 pm

The Bedazzler was apparently a "hey, let's see if we can make one" project based on a DHS demo of the Dazzler.

Firstly, there are limits to how small you can make this and still get a useful (for making people puke) light output. These are mainly due to (a) the amount of light you can emit per surface area, (b) the amount of thermal waste you can dissipated, and (c) the energy storage available. Effectively, the head has to have a fairly significant radius, and there needs to be a fairly significant battery pack attached. A smaller head isn't dumping as many photons into the environment. This likely means two things - it both affects a smaller area and it has a weaker effect. The device functions by overwhelming the human optical system with "oh shit" bad data. The first thing is it has to have significant amplitude relative to all other incoming light...not an easy task for a small light on a bright day. Possibly not even a meaningfully possible task, but I don't know of data examining the thresholds and falloff profiles associated with this effect. There's also a parts issue...a small-profile device (pocket flashlight) can maybe fit one high-power LED or several "standard" packages, versus 36-37 on the Bedazzler. That right there gives you your power ratio...and then you have to apply things like 1/r^2 falloff and logarithmic sensitivity, and the scaling of how input corresponds to the desired effect. It's not a promising picture, but maybe it's possible. If you try it, I'd be interested to know what results you get.

Secondly, there are limits to the effectiveness of this as a non-lethal weapon, and to non-lethal weapons in general. It's okay for pissing off crowds of protesters, especially if you truck-mount the sucker (although you run into a balancing act between effectiveness and risk of permanent damage). Even then...it may be of limited use since it's strictly line-of-sight. It's also probably possible to completely cancel with shutter glasses, and to partly cancel using polarized glasses of any sort. It's also easy to hit bystanders if you have a device that targets an area wide enough to give you a reasonable chance of hitting an individual attacker under live conditions. Non-lethal weapons in general are a difficult case...it's hard to shut down the body in any significant way without carrying a significant risk of permanent harm. Movies lie. This is more likely to err on the side of annoying but hardly incapacitating an attacker...which is sort of worse than doing nothing. Really, for personal defense, you'd be better off with a taser or chemical deterrent...neither of those is particularly free from issues either, but you can at least fit a meaningfully effective device in your pocket, and their definition of "incapacitate" is closer to "give me a plausible chance to leg it and call for help" than you'd get with an optical device.

That said, the Bedazzler has good documentation, so you're welcome to give it a try. I think there are likely to be a lot of problems, and I don't think it will be a viable personal defense device, but I'm interested to see your results.
tinsmith
 
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Re: Smaller version of Bedazzler?

by Tolgaozuygur on Mon Nov 29, 2010 3:22 pm

Hey Tinsmith,

Thanks a lot for your detailed reply.
I think I will be trying it. My target is not building an all capable stun gun, it is simply an experiment. I try to collect as much data as possible before giving it a try to increase the possibility of success.
I actually think of building one with around 10 leds. Using the lead acid battery in the documentation is a great idea. I believe a li-po would be able to power up a 10 led version. It might not last long, but it would have the advantage of size and weight.
Btw, 10 is just an assumption. I need to research more to see if there is a meaningful pattern which will affect the led amount I will need.
Also, I plan to use an ardweeny instead of boarduino to save up more space. Of course, a small hd case fan will be the cooling solution. I also plan to add a safety timer within the code that will shut down the leds after a determined time to avoid over-heat issues that can happen by mistake.

My actual target is just building a device that would annoy an attacker and manipulate their vision slightly.
No worries, I don't plan to rely on such device nor a taser (I have been practicing ninjutsu for years)
I enjoy building experimental stuff (non-lethal weapons, utility tools) which might not have any real combat effectiveness at all, just to give them a try. I think combining multiple hobbies together is something that we all desire and probably do :)

I will definitely let you know if I can come up with something that works. Thanks again!
Tolgaozuygur
 
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Re: Smaller version of Bedazzler?

by tinsmith on Mon Nov 29, 2010 3:44 pm

For overheat protection, a thermistor or thermal fuse would probably be better than a timer. You could also potentially play with the duty cycle a bit to minimize the energy used at a given level of effectiveness.
tinsmith
 
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Re: Smaller version of Bedazzler?

by stinkbutt on Mon Nov 29, 2010 6:10 pm

Or you could just mount the things on a big slab of copper with thermal grease. Get yourself a big enough heat sink and natural radiation and convection will keep the thing from melting.
Red M&M, Blue M&M: They all wind up the same color

stinkbutt
 
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Please be positive and constructive with your questions and comments.