# Looking for some advice



## Mark Wo (Jan 4, 2012)

I'm not an active poster to this site but an active reader. I've purchased many specialty lights from advice offered by members. I've also posted this in transportation as it sort or related. 

I'm looking for a very specific light. I have been unable to find anything on the web for what I need. Basically I need a low cost LED strobe or hazard light. My requirements are:

1. Powered by AA batteries (or other small batteries but not coin cells)
2. Flash for 25 hours (one flash/second of thereabout) without changing batteries
3. Viewable 360 degrees.
4. Viewable from 1500 feet or so
4. Lightweight
5. Works in cold weather, sometimes down to -20 deg. F. or so
6. Light will be about 6 feet off the ground and be viewable from 4 feet off the ground to 7 feet off the ground.
7. Flases either red or amber.
7. And naturally, inexpensive.

Imagine a light like this that you would put on top of you bike helmet that flashes. Doesn't have to be a heavy duty industrial light by any means but it is not a party light that you throw away after a couple of uses either. 

I've come across some of these emergency LED flares that are close I would guess. Haven't been able to determine how long they flash nor the weight but the are close. I've seen these on the Chinese mfg'ers site as well and am certain they can be pruchased for next to nothing if my past expereince holds here as well.

http://www.amazon.com/dp/B0019SKITA/?tag=cpf0b6-20

Thanks in advance for the advice.

Mark


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## GunnarGG (Jan 4, 2012)

Maybe Glo-Toob could work for you.
It's CR123 powered.
Inexpensive? Don't know.


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## jspeybro (Jan 5, 2012)

while I don't know anything to recommend, I'm currently working on a microcontroller that should be able to do what you want. The main challenge will probably be the -20°F (about -30°C) since not all electronics work at that temperature.

If you can make you're own housing, I could make you the electronics and led circuit if you want. (will need to order the LEDs though).
I tested my setup with a single 18650 and this lasted more than 48h while flashing 2 white leds at 1.4A at about 1Hz (a double flash/s). This can be done easily with red leds as well.

my design should go into a dive strobe, but it can obviously be used for other things as well. I'm using li-ions (18650), but it should work with 3 or 4 AA's in series as well I suppose. The drivers will produce some heat so this is perhaps enough to keep it working at the low temperatures. I'm not sure if which batteries are best for these temperatures, but I've heard good things about the LiFePO4 batteries.

If you are interested, let me know and we can discuss the details, this should be cheap .I may even be able to make you a housing as well, but I'll need to look into that (I'm thinking an acrylic tube with everything inside, similar to the divelight I'm working on). I'm currently at the point where I have everything working and I'm waiting for some parts for my own setup to arrive.

I'm curious where you plan to use this light. Snowcat or something?


Johan
edit: I checked the 2 main components I'm using and they work down to -40°C so that's ok.


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## Walterk (Jan 5, 2012)

* Subscribed *

Interested in a led strobe engine. 
I have floating light beacons attached to life-buoys, but low performorance with 4x D cell and a weak incan.
Just have to think of the 360degrees viewing angle.


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## Mark Wo (Jan 5, 2012)

jspeybro said:


> while I don't know anything to recommend, I'm currently working on a microcontroller that should be able to do what you want. The main challenge will probably be the -20°F (about -30°C) since not all electronics work at that temperature.
> 
> If you can make you're own housing, I could make you the electronics and led circuit if you want. (will need to order the LEDs though).
> I tested my setup with a single 18650 and this lasted more than 48h while flashing 2 white leds at 1.4A at about 1Hz (a double flash/s). This can be done easily with red leds as well.
> ...



Thank you for the reply and offer to help. I'm not as talented as you and would be unable to make a housing but I do have some old 360 marine lenses I worked on some time ago that could maybe work for this application.

The use is for a stationary object to keep people away, no snowcat or and moving vehicle.

Mark


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## jspeybro (Jan 5, 2012)

Walterk said:


> Interested in a led strobe engine.


I don't want to hijack Mark's thread so I'll point you to the thread with the current status of this project.


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## jspeybro (Jan 5, 2012)

Mark Wo said:


> Thank you for the reply and offer to help. I'm not as talented as you and would be unable to make a housing but I do have some old 360 marine lenses I worked on some time ago that could maybe work for this application.
> 
> The use is for a stationary object to keep people away, no snowcat or and moving vehicle.
> 
> Mark



Could you provide a picture and maybe some dimensions of this lens (mainly the inside and outside diameter of the lens), I could check if it could be used. If that doesn't work, I was thinking in the direction of side-emitting lenses from carclo for creating a 360° beam without emitting most of the light upwards (and cost just a few euros). This could in fact be made quite small.
I have a lathe, but no mill, so I'll need to think about how to fix everything in the acrylic tube. I still need to learn a lot about the lathe, but consider this a new challenge for me


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## Mark Wo (Jan 11, 2012)

Sorry for the delay - I've been away for a little while.

I have looked all over for these lenses with no luck. I can't even find the drawings anymore. This is a disappointment for me as they were really well done. Anyway, this isn't too hard of a challenge I don't think. Many of the marine whiet stern lights (that utilize LED's as the light source) have similar lenses. The LED shines up towards the sky and the LED housing directs that light perpendicular to the light output. These lenses are designed to emit the light 360 degrees and be seen from 2 miles away. Here is a link to a couple of them.

http://www.attwoodmarine.com/store/category/lighting/navigation/led/all-round

Mark


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