paso = 0.5;
tiempo=0:paso:250;
function dhdt=dhdt(h,t)
    if t<=30
        f=3;
    else
        f=3+0.01*t;
        if f > = 5;
              f = 5;
        end
    end
    dhdt=f-x*h;
endfunction
pv=bias+kc(er+ti*int(Edt)+td*dE/dt)