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From: frerichs@adsl (dfRERICHS)
Newsgroups: sci.electronics
Subject: Re: IR Reception - Modulation and Quality
Message-ID: <1991May5.181912.24356@ux1.cso.uiuc.edu>
Date: 5 May 91 18:19:12 GMT
References: <2766.27E40773@ofa123.fidonet.org> <159639@felix.UUCP> <237@tdatirv.UUCP>
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In article <159639@felix.UUCP> dennisg@felix.UUCP (Dennis Griesser) writes:
>OK, so let's talk detector quality.  Specifically noise immunity.
>
>Like half the people on the net, I have been experimenting with the IR
>detector module made by Sharp, sold through Radio Shack.  There are occasional
>bursts of optical noise that fool the receiver module into believing that it
>has seen an IR signal.  I can deal with this.  The incidence is low.
>
>
>Any ideas, gang?


What you are seeing is NOT optical noise coming into the detector...
it is EM inside the unit.

It is very important to tie the case of the detector/demod to ground (it
seems they didn't bother at Sharp).  Failure to do this makes for a noisy
environment for the circuit inside and causes noise bursts on the output
pin.

djf