Path: utzoo!attcan!uunet!pilchuck!ssc!markz
From: markz@ssc.UUCP (Mark Zenier)
Newsgroups: sci.electronics
Subject: Re: Passive Infrared Detectors
Message-ID: <1639@ssc.UUCP>
Date: 12 Jan 89 07:29:53 GMT
References: <276@serene.UUCP> <762@pedsga.UUCP>
Organization: SSC, Inc., Seattle, WA
Lines: 27

In article <762@pedsga.UUCP>, jeffj@pedsga.UUCP writes:
> 
> In <276@serene.UUCP>, Greg Bell asks:
> >  Does anyone here have any experience with IR motion detectors?   
...
> Similar units are now available in hardware stores
> for turning on the lights when you approach the house.
> On sale, it's around $30, so don't spend too much money experimenting.

I took apart an RCA sensor for a floodlight switch.  It's a 1.5 inch
square pc board with a bunch of surface mount (they are really using that
stuff now, gack) resistors and transistors along with an op amp or two.

The interface seemed to be power (into a 7808, so around 11-12 volts),
ground, and a signal output.  There were sensitivity and duration (it goes
to a relay box to switch on a light) adjustments on the sensor.

Its field of view is fan shaped, not very high 20 - 40 degrees, but
quite wide, maybe  150 degrees.  It was sensitive enough that you
couldn't seem to able to sneak by it, even the cat could trigger it.

Hard to duplicate for the 25 to 30 buck price, even if you throw out half
the stuff that comes with it.

Mark Zenier    uunet!nwnexus!pilchuck!ssc!markz    markz@ssc.uucp
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