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<DIV>Thanks Chuck, Jon and Triffid for all the input.</DIV>
<DIV> </DIV>
<DIV>Makes me think would be useful to exaggerate resistances and inductances in
a sample circuit OR to use a simulation to show what is going on.</DIV>
<DIV> </DIV>
<DIV>A cool, free tool I have played with in the past is LTspice/SwitcherCAD
from Linear Technology</DIV>
<DIV> </DIV>
<DIV><A
href="http://www.linear.com/designtools/software/switchercad.jsp">http://www.linear.com/designtools/software/switchercad.jsp</A></DIV>
<DIV> </DIV>
<DIV>provides an easy to use schematic capture program combined with circuit
simulator -- e.g. virtual oscilloscopes... need to re-learn that
tool.</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>One problem I still have, is Scott's car uses one battery for processor and
one for motor.</DIV>
<DIV>When motor turns on-and-off current changes in motor supply loop, but not
in processor loop,</DIV>
<DIV>so my last email was flawed there in talking about his processor loop
reacting to motor current dropping to zero when relay opened and adding
inductive energy to processor ground.</DIV>
<DIV> </DIV>
<DIV>I have noticed the need for processor decoupling on even the smallest AVR
microcontrollers, e.g. Tiny13 running unloaded using internal RC
oscillator on a breadboard did not work. Of course we are talking 6 inches + of
wire runs from 4 AA batteries in series.</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>Ron</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
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<DIV> </DIV></FONT><BR><BR><BR><DIV><FONT style="color: black; font: normal 10pt ARIAL, SAN-SERIF;"><HR style="MARGIN-TOP: 10px">Start the year off right. <A title="http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489" href="http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489" target="_blank">Easy ways to stay in shape</A> in the new year. </FONT></DIV></BODY></HTML>