Re: capacitor equation solution not working

*To*: mathgroup at smc.vnet.net*Subject*: [mg119701] Re: capacitor equation solution not working*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Fri, 17 Jun 2011 05:53:09 -0400 (EDT)*References*: <201106170409.AAA28826@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

Surely that is NOT your code; it has at least four misspellings and two fatal syntax errors -- == where you need = (as in Soleq = ...) and the comma before [[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] Bobby On Thu, 16 Jun 2011 23:09:13 -0500, J and B <noslowski at 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 at yahoo.com

**Follow-Ups**:**Re: capacitor equation solution not working***From:*"J and B" <noslowski@comcast.net>

**Re: capacitor equation solution not working***From:*"J and B" <noslowski@comcast.net>

**Re: capacitor equation solution not working***From:*"J and B" <noslowski@comcast.net>

**References**:**capacitor equation solution not working***From:*"J and B" <noslowski@comcast.net>