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ArcticMyst Security by Avery

long range energy transfer using a laser

Ablaze

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Hmmm... interesting avatar geeky. Makes me want to steal it!

I won't, but I still want to.
 





sss

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Surprisingly most solar cells are most sensitive in near IR. IR will also have least losses in the air. If you only want few mA, then maybe even 200mW IR laser could do that. And solar cell can charge during the day too.
Divergence of the beam would be the main problem. At 100m, the laser beam will be larger then even 5x5cm. More like 50x50cm. That is with common small lens at laser side.
To get better divergence, you would need larger diameter lens, or curved mirror, at laser side. Things like that tends to be expansive.

great , so i'll need ir laser with some optics .
about the optics , i read that beam expanders improve the divergence .
so if i use 10x beam expander , does it means that it will expand the beam by 10 ? so if the beam diameter at entry is 1mm , the output beam is 1cm ?
and by using this expender , by how much does it improves divergence?
lets say the beam is 1mm at entry to the expander , at expander out the beam is 1cm , now how big its gonna be at 100m ?

using only solar cell is not gonna help , as i have no direct sunlight in area .
 

DrSid

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Generally double aperture means half divergence. So if you increase beam diameter 10 times, the dot will be 10 times smaller. On the other hand, any added optics will reduce power of the beam. The optics should also be specially coated based on wavelength used. Problem with common beam expanders would be that they are not usually made for IR.
For some first tests, try 200mW IR laser from O-like. It's rather cheap, and it could even give you those few mA you need. But make sure you also get some good IR goggles. IR is especially bad in that is almost invisible.
 
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A solar panel with no direct sunlight is still a better option than using a laser. But... is "better" good enough? Hard to know if you won't tell us how much power the device requires.
 
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Looks like he's installing a wireless camera where perhaps
he shouldn't...:whistle:

Jerry
 
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sss

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A solar panel with no direct sunlight is still a better option than using a laser. But... is "better" good enough? Hard to know if you won't tell us how much power the device requires.

device requiers approx 400-200ma @ 3.7v ,but as already stated , the solar cell will only charge the battery when its not used .
 

DTR

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Would a person be able to come in the path of the laser? If so you could blind them. If it is secrete I am sure you don't have warning signs saying to keep eye protection on when in this 100 meter area drawing attention to it.
 
Joined
Jan 5, 2011
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Calculate a power needed for your cell. Get a laser and optics. Expand beam to a safe size which does not exist :whistle: as in a worst case scenario someone may come with binoculars to look at your secret device. :gun:

May you bury a cable? It might be cheaper and more simple.
 

Ablaze

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I think there are probably cheaper, simpler solutions. If you pay enough you can find non-rechargeable batteries with an absolutely massive energy density. You can get a 9v battery that will power a smoke detector for 15-20 years, for example.

If you put a 10 year battery in there, would that be enough? I think it would be a lot cheaper then mucking around with solar collectors and IR lasers.
 

Joe Mo

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I think there are probably cheaper, simpler solutions. If you pay enough you can find non-rechargeable batteries with an absolutely massive energy density. You can get a 9v battery that will power a smoke detector for 15-20 years, for example.

If you put a 10 year battery in there, would that be enough? I think it would be a lot cheaper then mucking around with solar collectors and IR lasers.

Can you find me a link to one of these? :thinking: I tried googling it but no dice. I'd like one for my LPM that runs off 9v.
 
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Ablaze

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Hmm.. well I remember them from when I was getting my software degree. The electronic guys would order them, but they had a special catalog. The batteries were real, but they were made out of some material that was extremely dangerous and was forbidden to be shipped via regular mail.

Honestly, I've looked for them several times since then and failed. I know they are out there, they are just obscured from the general population somehow.

EDIT: This is the best I could come up with atm.
 
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Joined
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I think there are probably cheaper, simpler solutions. If you pay enough you can find non-rechargeable batteries with an absolutely massive energy density. You can get a 9v battery that will power a smoke detector for 15-20 years, for example.

If you put a 10 year battery in there, would that be enough? I think it would be a lot cheaper then mucking around with solar collectors and IR lasers.

There is a big difference in powering a Smoke Detector for 10 years
(a standard 9Volt battery can run it for at least 1 year) and powering
400mA for 10 years....

Jerry
 

sss

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Get a laser and optics. Expand beam to a safe size which does not exist :whistle: as in a worst case scenario someone may come with binoculars to look at your secret device. :gun:

May you bury a cable? It might be cheaper and more simple.

easy to say huh .
where do i get this laser and optics ?
looks like those ir laser are really poor with high divergence . i'm not sure if beam expander would help to reduce the beam diameter to approx 5cm at 100m.
is it possible to focus the beam at the expander input to a tiny dot , so at the output it will be a bit larger , but at 100m it wont be too big ?
what type of focusing mechanism is needed ?
is it possible to use two expanders in series ?
the beam will be located 6m high , and the target is a it higher , around 8-9m .no buildings in between .

can somebody reccomend cheap ir laser diode just to test power output on a solar cell ? (from short distance)
 
Joined
Jan 5, 2011
Messages
417
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easy to say huh .
where do i get this laser and optics ?
looks like those ir laser are really poor with high divergence . i'm not sure if beam expander would help to reduce the beam diameter to approx 5cm at 100m.
is it possible to focus the beam at the expander input to a tiny dot , so at the output it will be a bit larger , but at 100m it wont be too big ?
what type of focusing mechanism is needed ?
is it possible to use two expanders in series ?
the beam will be located 6m high , and the target is a it higher , around 8-9m .no buildings in between .

can somebody reccomend cheap ir laser diode just to test power output on a solar cell ? (from short distance)

I'll not do your homework :tired:

Some months ago somebody posted a video with burning balloons over a huge distance. They used an astronomical telescope or binoculars :thinking:
 

DrSid

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Telescope is good, especially mirror type, as the mirror has practically no losses. But it's pretty tricky to prepare the beam for it. You need to have the laser near focus point of the mirror, and at the same time cover full mirror surface. Best method to achieve this for me was using normal Aixiz focusable module, focus to really close, let the beam 'cross' and then expand again .. in other words put the focus point of the module into focus point of the mirror. Still it's hard to make it right. All axes must be perfectly aligned, and it must be very robust.
 




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