Newsgroups: comp.robotics
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From: leebr@ecf.toronto.edu (LEE  BRIAN)
Subject: Re: Motor noise locks up uController
Message-ID: <CHH8zC.Kyv@ecf.toronto.edu>
Sender: news@ecf.toronto.edu (News Administrator)
Organization: University of Toronto, Engineering Computing Facility
References: <2cmqja$sga@usenet.rpi.edu> <1993Dec1.162346.20069@mksol.dseg.ti.com> <3780@rc1.vub.ac.be> <2do85b$43t@vixen.cso.uiuc.edu>
Date: Fri, 3 Dec 1993 20:59:35 GMT
Lines: 25

some things (I haven't followed the whole thread, so I don't know if
this has been mentioned before):

    1 - give separate power supply lines for logic and a separate one for
        the relays/motors/power transistors, etc or maybe have even a
        single point ground (logic and drive grounds connected only
        at one point) -> best to think about the whole thing as
        each wire as a resistor, and since lots of current is being drawn,
        the voltage drop is quite large

    2 - clamp the motor terminals between + and ground, so they don't go
        over it (V = L * dI/dt) depending on the directions desired,
        clamp each of the motor terminals with 1 or 2 diodes (1N4xxx's go
        great)

    3 - similarly, clamp relays with a diode

have fun!
bjl

-- 
+=[O]==================================================================[<]=[>]=+
|  Brian Jonathan Lee (aka "hojo")      |  "Bleh!"                             |
|      leebr@skule.ecf.toronto.edu      |  "Got'er, done'er, done'er, got'er"  |
|      leebr@ugsparc0.eecg.toronto.edu  |  "Evil thy name is NETREK!"          |
