help me to solve a problem

dckjain · Dec 13, 2007

i want to design a torch in which i am supposed to use any number of 5mm LED but i should be able to throw a light for about 250-300 feet (75-90yards)

what should be the optimal number of LEDs and the lumen's required

and the rechargeable battery required for the peak use of around 2- 3 hours

please suggest any reflector and lens if u have any idea.

actually i am from india and dont have enough idea about long range torches

please help me

divine · Dec 13, 2007

To be honest, I don't think 5mm's are bright enough to throw that far.

If you have to use more than a few LED's, it will be difficult to design a reflector to get good throw.

Gunner12 · Dec 13, 2007

You would need a high power LED and a good reflector. I would recommend the Cree XR-E P4-R2 bin LED or the Seoul P4 U bin LED.

5mm ones won't work, you'll need so many to have to be able to see that it would be a pain to lug around.

There are actually many long throwing lights, like the Dereelight DBS, which should hit 600 ft without much problem. Even this light would work for your requirements.

What batteries would you like to use?

:welcome:

half-watt · Dec 13, 2007

agreed on the choice of 5mm LEDs *NOT* being the right LED for the task.

that said, a plano-convex (aka PCX aka aspheric) lens is probably going to be needed for this task regardless of the LED used - at the very least, probably a single Cree LED is all that would be required if the lens is used to focus the light.

i have some 3W and 5W SSC LEDs in MagLite hosts using PCX lens and they handle 250'.

dckjain · Dec 14, 2007

its a rechargeable battery 12v

dckjain · Dec 14, 2007

how do u design a reflector

Empath · Dec 14, 2007

Dckjain,
I have removed your other threads that deal with the same topic. They were generating reports of crossposting, since other members are aware that crossposting and multiple threads of the same topic is against the rules. Please confine this topic to just this thread.

help me to solve a problem

dckjain

Newly Enlightened

divine

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Gunner12

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half-watt

Flashlight Enthusiast

dckjain

Newly Enlightened

dckjain

Newly Enlightened

Empath

Flashaholic

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