Determine the voltage across the capacitor:
Let us compute the voltage across the capacitor for t≥0 using the following expression:
${{v}_{C}}(t)={{V}_{c0}}{{e}^{-t/\tau }}u(t)$
Whereas the capacitor initial voltage is 5V and time constant τ=RC=0.2s.
- You May Also Read: Series RC Circuit Analysis Theory
It’s time to write some code in Matlab to calculate the capacitor voltage:
Matlab Code for RC Circuit
%RC Circuit Analysis
clear all;close all;clc
%%Circuit Parameters
R= 2e3; % Resistance (2kOhm)
C= 100e-6; % Capacitance (100microFarad)
tau=R*C; % Circuit Time Constant
Vco=5; % Capacitor initial Voltage at t=0
Time=0:tau/100:5*tau; % Sampling Time
Vc=Vco.*exp(-Time./tau).*heaviside(Time);
%%Plotting the Result
plot(Time,Vc)
xlabel('Time (s)')
ylabel('Amplitude (V)')
title('V_C')
axis([0 5*tau 0 6]) % Manual Axis Limits adjustment
%=============================================
Results:

