jeffj@pedsga.UUCP (01/11/89)
In <276@serene.UUCP>, Greg Bell asks: > Does anyone here have any experience with IR motion detectors? I got > some samples and some great app notes from Amperex. Included was a sample > circuit. Pretty fun toy. Their range is incredible. I'd like to know of > any experience others have had with these types of circuits... I've seen several passive infrared (PIR) sensors used as part of alarm systems. The units have a plastic lens that directs the viewing area into a pattern. Greatest sensitivity is when you walk across from one lens' area to another. 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. My experience: well, I started testing one of these units for use as an indoor alarm. Other things took priority. It's cheap, it works, but don't over rely on it. __________ What do electrical engineers do when capacitors fail? They have Tantalum tantrums. Jeffrey Jonas allegra!io!mtune ---------> petsd!pedsga!jeffj decvax!mcnc!rutgers _____/
markz@ssc.UUCP (Mark Zenier) (01/12/89)
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 uunet!amc! uw-beaver!tikal!