On Sunday 23 April 2017 10:41:06 Ralph Stirling wrote: > Gene, > > You might find it useful look at how industrial sensors do this. I > use a lot of Automation Direct fiber prox sensors. They have both > thru-beam and diffuse reflective types. In any case, they always have > lenses on the ends of the fibers. > > https://www.automationdirect.com/adc/Shopping/Catalog/Sensors_-z-_Enco >ders/Fiber_Optic_Sensors/SSF_Fiber_Sensors > Not at that price level Ralph, way out of reach. Thanks for the link, educational to be sure.
> They have a couple of different sensor heads. For reflective > applications, I prefer the devices with programmable threshold and > gain. Non-adjustable ones are ok for thru-beam. > > It may be possible to use consumer optical link parts to replicate > these sensors, but not as simple as it first appears. The key is > focusing the light at the fiber end. You might try a $2 laser pointer > module for the transmitter side to see if coherent light will reduce > the need for a lens. It may lose its coherence in the fiber though. > > -- Ralph > > On Apr 22, 2017 6:25 PM, Gene Heskett <[email protected]> wrote: > > On Saturday 22 April 2017 20:03:05 dave wrote: > > Gene, > > I thought about the limit switch thing years ago. The problem is > > getting enough energy into a small fiber. > > 62.5 um is not a large target. However, 900 um fiber if you can find > > it might be just right. For short runs even plastic fiber should > > work. > > > > Dave > > This stuff I'm looking at is plastic, a 1.2mm core with a 2.0mm > jacket. Plastic of course. The longest run would in the 16 feet range. > > Step-dir lines to the drivers maybe 40". At the response times I'd > expect, losses should not be that bad even in plastic. > > I watched the local cable folks install a fiber link from our studio > output to the cable head end in Enterprise WV, 39 klicks long as the > cable went. This was in about 1998. Had to send the splicer back and > get new knives or something in it, but when it came back, the first > cut & termination they did was good. 0.47 db of loss in that 39 klicks > of fiber. I half expected 15 to 20 db of loss. Blew me away. I > probably failed but tried not to look impressed. > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
