Newsgroups: comp.robotics
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From: nagle@netcom.com (John Nagle)
Subject: Re: Set Switch
Message-ID: <nagleD81DDA.3qr@netcom.com>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
References: <D80BoC.FC5@boss.cs.ohiou.edu>
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Date: Thu, 4 May 1995 04:19:57 GMT
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smcfarla@oucsace.cs.ohiou.edu (Sidney Edward McFarland) writes:
>Well, Set Switch sounds like the most probable name. I'm looking for a
>type of switch that retains it's current status (off or on) unless sent a
>certain voltage pulse. Then it would change either from off to on or from
>on to off. Is there such a switch and where can I buy one (many).
>In case you're wondering, I'm trying to use the limiting 8 data lines on
>my parallel port to control 255 motors. I want to do this by just using
>the parallel pins to change the state of the motors. For example, it motor
>1 is running forward, I would send a signal on pin 4 which would change
>the state of a switch (from on to off) which would turn the motor off. Any
>idea?

     There are boards for PCs which will allow you to operate large
numbers of relay contacts.  See "Circuit Cellar INK" or "Embedded Computing"
for ads.  

     Control via toggling is a terrible idea.  Things get out of sync.
You do something like this by sending separate signals for on and off.

					John Nagle
