Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!agate!howland.reston.ans.net!paladin.american.edu!constellation!osuunx.ucc.okstate.edu!olesun!gcouger
From: gcouger@olesun.okstate.edu (Gordon Couger)
Subject: Re: Getting 16 Relay outputs from a PC
Message-ID: <1994Feb25.165220.25960@osuunx.ucc.okstate.edu>
Sender: news@osuunx.ucc.okstate.edu (USENET News System)
Nntp-Posting-Host: olesun.agen.okstate.edu
Organization: Biosystems and Agricultural Engineering at Oklahoma State Univ.
References: <markdahlCLpMBt.495@netcom.com>
Distribution: usa
Date: Fri, 25 Feb 1994 16:52:20 GMT
Lines: 27

In article <markdahlCLpMBt.495@netcom.com>,
Mark Dahlen <markdahl@netcom.com> wrote:
>
>I'm in great need for 16 or more Relay outputs from a PC running Qbasic.  
>The use would be to control motors and lights for a little robot that I'm 
>building.   I'd go out and purchase a board for around $150, but I'd 
>rather just see if I can make one for less.  It could use the serial port 
>or the parallel port.  The relays need to be at least 10 amp rating.   
Add a second parallel port and hook lines 2-9 to IR511 FET I would probably
use opto-isolators between the parallel line and the gate of the 511 to
keep switching noise out of the computer. Also a .01 ufd capictor needs
to go from the gate to ground to keep the 511 from osilating. Also a 2 or
3K resistor to pull the gate to the desired start up state. WARNING on
boot up the parallel port does some flopping around ususaly coming to
on off on off ... in the end. This is not the same for all computers.
Because of this you can get some strange behavior at boot up and in
crashes.
Good luck
Gordon


                              Gordon Couger                            
                              Biosystems & Agricultural Engineering              
                              Oklahoma State University                         
                              114 Ag Hall, Stillwater, OK  74074                 
 gcouger@olesun.agen.okstate.edu 405-744-9763 day 624-2855 evenings 
    I do not speak for my employer
