On 10/5/06, alan smith wrote: > Long range....well....in the world of micro electronics, 24" is a long distance. > So looking for a IR emitter/dectector pair that can work at those distances. > Basically its a beam detect type thing....to detect when the beam is broken > or disturbed. > > Anyone have a favorite device? Maybe you can find these kind of parts from OSRAM or AVago Tech (used to be part of Agilent). http://www.osram-os.com/ http://www.avagotech.com In paticular, some of the IR emitter has built-in lens. For example, OSRAM SFH4209 is pretty powerful. I've tried it with BPW 34 FS (with visible light cut) and they are good combonations. Or you may want to use other photo-transistors if you do not need the speed. In that applications, we achieved more than 45m with lens and pulsed light (Through-beam) and more than 1.2m for diffusive type. Without external lens and with DC light, I am not so sure. But I think it might still be okay for 24 inches (610mm) in through-beam mode. Xiaofan -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist