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From: ee8kh@gdt.bath.ac.uk (K House)
Newsgroups: comp.robotics,sci.electronics
Subject: Re: Sensing a known location to reference off of
Message-ID: <1991May17.124120.2147@gdt.bath.ac.uk>
Date: 17 May 91 12:41:20 GMT
References: <1991May15.005403.28812@src.honeywell.com> <1991May15.150813.26223@sctc.com>
Organization: University of Bath, England
Lines: 24

smith@sctc.com (Rick Smith) writes:

STUFF DELETED

>Naturally, the perfect thing is to put a pair for sensing each slot
>in your library, thought that's probably too expensive. But don't
>skimp - have one at each end of your rack, and add a few in between
>so as to minimize the degree to which you trust positioning to the
>stepper motor. You might want to always find the closest LED to the
>slot and then step from there.

Surely you just use one slotted opto-switch on the moving part.
You have little beam breakers between each disc.
Cheaper methinks

>Rick.
>smith@sctc.com    Arden Hills, Minnesota

Kevin
-- 

"I hear the word for love, I hear the word for death,      ___           
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