% Biezl 2008
%
% Eingang Strom, Ausgang Spannung

f_res = 1000. % 1. kHz
f_force = 1005. % 1.1 kHz
% f_res = 1 / (2*pi*sqrt(L*C))
% C = 1/L * 1/(2*pi*f_res)^2

L = 20.e-3 % 20. mH
%C = 1.25e-6 % 1.25 uF
C = 1/L * 1/(2*pi*f_res)^2
R_p = 4000. % Ohm

i_max = 10.e-3 % 10 mA

% tStep = 1000*f_res
tStep = 25.e-6 % 50 us

steps = 40 * 40 % 40 Waves

iErregung = i_max * sin(2*pi*f_force*tStep*(0:1:steps-1));
offset = 100;
iErregung = [zeros(1, offset), iErregung];
% Speichergrößen

I_L = 0;
U_C = 0;

dataU_C = zeros(1, steps+offset);

for i=offset:1:steps+offset-1

  I_C = iErregung(1, i+1) - I_L - U_C/R_p;

  deltaU_C = I_C * tStep/C;

  U_C = deltaU_C + U_C;
  U_L = U_C;
  deltaI_L = U_L * tStep/L;

  %U_C = deltaU_C + U_C; % ???
  I_L = deltaI_L + I_L;

  %U_C
  dataU_C(1, i+1) = U_C;

end

plot((0:1:steps+offset-1)*tStep*1000., iErregung*1000., ";Erregung in mA;", \
    (0:1:steps+offset-1)*tStep*1000., dataU_C, ";Antwort in V;");

filename = sprintf( "./lc-kreis_f_force_%i_R_p_%i.ps", f_force, R_p);
printf(filename)
print(filename, "-dps2", "-landscape");

pause