```Date: Jun 18, 2011 4:48 PM
Author: noslowski
Subject: Re: capacitor equation solution not working

Sorry for not typing my code in correctly.  I have the same code as you,that is mentioned in this emaili[t_] := If[t < 10 || t > 60, 0, 1]eq = v'[t] == i[t]/c;c = 1;soleq = v[t] /. First@NDSolve[{eq, v[0] == 0}, v[t], {t, 0, 100}];Plot[soleq, {t, 0, 100}]But I thought it had to be wrong, since the capacitor never came back tozero.  I did not realize that I had to have a resistor in the circuit, asseveral people pointed out.Thanks for your help-----Original Message-----From: DrMajorBob [mailto:btreat1@austin.rr.com] Sent: Friday, June 17, 2011 5:53 AMSubject: Re: capacitor equation solution not workingSurely that is NOT your code; it has at least four misspellings and twofatal syntax errors -- == where you need = (as in Soleq = ...) and the commabefore [[1]].If you ran that code, you'd see error messages, not just a constant plot.This works, however:i[t_] := If[t < 10 || t > 60, 0, 1]eq = v'[t] == i[t]/c;c = 1;soleq = v[t] /. First@NDSolve[{eq, v[0] == 0}, v[t], {t, 0, 100}];Plot[soleq, {t, 0, 100}]I'd also suggest THIS for the first line:i[t_] := Boole[10 <= t <= 60]BobbyOn Thu, 16 Jun 2011 23:09:13 -0500, J and B <noslowski@comcast.net> wrote:> I am trying to solve a very simple circuit, one that has only a > capacitor in it.  What am I doing wrong?  The final graph should show > that the capacitor has discharged, but its staying constant.  I have > current starting at t=10 and ending at t=60.> I hope I have used the correct way to put in my code, I am using a new > computer and I having trouble with my email program.  Any advice would > be appreciated.>> Thanks>> My code.> I[t_]:= If[t<10||t>60,0,1]> Plot[i[t],{t,0,100}]> Eq=v'[t]==i[t]/c> c=1;> Soleq==v[t]/.NDSolve[{eq,v[0]==0},v[t],{t,0,100}],[[1]]> Plot[soleq,{t,0,100}]--DrMajorBob@yahoo.com
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