On Sunday 11 October 2009, Sven Wesley wrote: >2009/10/11 Gene Heskett <gene.hesk...@gmail.com> > >> [Gene gives a lesson] > >Sometimes I wonder if I shouldn't take all these mail and make a book out > of them. :)
Be my guest as long as you give a credit line. I did have a copyright notice in my sig, but its been 30+ years since my musings were actually made into a competing commercial product. Now I'm just another old fart who has to expound on this stuff to keep it fresh and sufficiently accurate for use in my own mind, whats left of it. My biggest fear now is 'do I have it right' when I go off on something that seems more widely miss-understood than it should be. And I get a certain personal pleasure out of trying to put some of the stuff I've dealt with for 60 years, into a format that really does educate the reader. As in any field of endeavor, one can get lost in the 'lingo' of the work, and the (fill in avocation here) who needs to do this is working in a different lingo, it can be confusing to bridge that language gap. I try, but don't always succeed. Don't be afraid to call me out when I blow it. >But the whole discussion makes me think of another idea I had one time. Why >aren't we using optical wires? >They are cheap (cheaper than copper cables), can be extremely long and >they'll never pickup noise, and on top of that the encoder can be passive. >One fibre for light feed to the encoder, the encoder only consists of a >fibre splitter and an optical wheel. Three fibres return A/B/Index channels >and all the logic can be inside the driver. > Other than the expense of the fittings, and the often very pricy machines needed for doing the cutting and splicing, no reason whatsoever for the relatively low data rates we are using. However I don't know as I'd say they were interference free. If room florescent light can get in, there is that possibility. But most of that stuff runs in the infrared range because the clad coated glass fiber is more transparent there, and silicon can easily generate fairly high powers, and detect, stuff in the 880 nanometer range. When the local cable decided we should be hooked up by fiber since their new head end was at a very low elevation making an off-air pickup very difficult to do, they brought a fiber to the tv station but made us buy the optical relays, which were about $9k for both ends, capable of doing 4 channels of video with stereo audio on all 4. We are now using all 4 channels too. In testing the final splices, they made the local one 3 times, but the net result was a .3 db loss in the 39 kilometers of fiber. For what we need to do, we could almost do it in the hobby shop plastic fiber they sell so you only need one lamp to light up all the twinklies on your models. But I suspect its lifetime would be limited by the aging and yellowing of the plastic. Real glass would be better in that regard. And real glass comes bound in an opaque and abrasion resistant covering. This might be a place where an enterprisingly minded individual could make up some of this product if it could be made at copper competitive prices. That, I rather doubt unless the military has needs that would underwrite the developments cost. An excellent idea on the face of it. But the first to do it _is_ going to burn through some money getting it right I fear. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> In practice, failures in system development, like unemployment in Russia, happens a lot despite official propaganda to the contrary. -- Paul Licker ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
