From: sburton@dres.dnd.ca (Stan Burton)
Subject: Re: Long distance IR detection
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In article <wb9omc.735430855@dynamo.ecn.purdue.edu> wb9omc@dynamo.ecn.purdue.edu (Duane P Mantick) writes:
>Duane
>	Yeesh, you WILL be nailing those IRLEDs.  May I suggest getting your
>mitts on the Siemens SFH484-2 IRLED?  This unit is designed to take some big
>current pulses if you can get your duty cycle down a bit.  It will output
>nearly a watt (975 mW) with REAL short duty cycle times.
>
>(nice thing about the SFH484-2 is that it is CHEAP.  I got mine for about
>50 cents a piece, even though I had to buy 100 of them....)

Are you saying that you have some extras that you would like to do some cost
recovery on?  I may be interested.  I think for practical and cost reasons I
am limited to envelope detection so that leaves me with only increasing the
output power and increasing the optical gain at the receiver as methods to
extend range.

>	BTW, I have seen IRLEDs with outputs up to 6 watts...honest,
>6 WATTS.  I don't have the book here at work so I can't recall the company
>name.  The 6 watter ain't cheap, around $108 but if you want some power,
>mamamia, that's pretty hot.  They also have a 4 watt, a 2 watt and a
>1 watt device in their line, and will sell small quan. to individuals.
>If you are interested, I can find the book at home and get the
>pertinent info.

Yes I'm interested in the company name.  I have access to an extensive data
book collection.  With that kind of power, are we getting into an area where
eye safety is getting to be a problem.

>	Now, as for the position detector, you might try ELTEC in Florida.
>Phone number listed in the 92/93 ETID is 904-253-5328.  They seem like
>nice people.  Their specialty is passive infrared detection devices,
>so they might be able to help you out.

They are a long way from me but they might be a better source than I can find
around here.

>	I'm curious about your applications if you don't mind saying.
>The device sounds like it could be useful in a lasertag game, although you'd
>need to up your carrier signal concept to 58.8 KHz......

I'm keeping my application confidential for now.  Raising the frequency should
be no problem, in fact one respondent to my question said that I may not have
to mimic the 50% duty cycle normally used by IR detector chips.

--

Stan Burton (DND/CRAD/DRES/DTD/MSS/AGCG)                 sburton@dres.dnd.ca
(403) 544-4737     DRE Suffield, Box 4000, Medicine Hat, AB, Canada, T1A 8K6
