Determine the voltage across the inductor in an RL circuit:

Let us compute the voltage across the inductor for t≥0 using the following expression:

${{v}_{L}}(t)=-R{{I}_{lo}}{{e}^{-t/\tau }}u(t)$

Whereas the inductor initial current is 1mA and time constant τ=L/R=5ms.

It’s time to write some code in Matlab to calculate the inductor voltage:

%RL Circuit Analysis clear all;close all;clc %%Circuit Parameters R= 20; % Resistance (20 Ohm) L= 100e-3; % Inductance (100mH) tau=L/R; % RL Time Constant I_lo=1e-3; % Inductor Initial Current Time=0:tau/100:5*tau; % Sampling Time V_L=-R*I_lo.*exp(-Time./tau).*heaviside(Time); plot(Time,V_L) xlabel('Time (s)') ylabel('Amplitude (V)') title('V_L') axis([0 5*tau -21e-3 0]) % Manual Axis Limits adjustment %=============================================