[NLRS] Light wave communications

[Dr. Gerald N. Johnson]

IR LEDs today can be had with ten or 100 times the power that each of 
the best ones you could get 10 years ago would do so it might only take 
four instead of 300.

The VKs that have been playing with LEDS and IR LEDs have been using 
arrays of 9 or 16 each with its own lens to do some pretty good distances.

73, Jerry, K0CQ

On 3/16/2013 1:37 PM, John (JK) Kalenowsky, K9JK wrote:
>
>
> SO...is this topic more like "Remote Controls on Steroids"? ;-)
>
> A start-up that I worked with briefly (about 10 years ago) developed a
> way of extending the IR link for Palm Pilots to be able to send info to
> ALL Palm Pilots in a classroom (possibly larger area...distances of up
> to 150 feet were achieved with full data bandwidth, not that the data
> rate/volume was that challenging/large), it was quite reliable in a
> classroom on the order of a couple of hundred square feet.
>
> If my memory serves me correctly, each of the emitter units used about
> 300 Infrared LEDs (the sales rep at Arrow loved that order!). I don't
> recall how much the actual radiated power was for that. Also, it was
> scattered, the IR LEDs were on 4 separate panels in the emitter unit.
>
> I never thought of it at the time BUT I wonder what might have been
> possible if the output of the 300 IR LEDs had been 'focused' to a more
> directive path.
>
> 73, JK
>
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