Low Pass Filter GUI: A MATLAB Tool for Understanding RC Circuit Filters, Lecture notes of Matlab skills

Download Low Pass Filter GUI: A MATLAB Tool for Understanding RC Circuit Filters and more Lecture notes Matlab skills in PDF only on Docsity! Low Pass Filter MATLAB GUI Documentation INTRODUCTION The Low Pass Filter GUI was designed to help a student better understand the effect of a low- pass filter RC circuit on a sinusoidal signal. This GUI allows the user to vary the time constant of the system and the frequency of the input signal, and view the resulting response in the time and frequency domains. This document contains instruction on the usage of the GUI. Other documents are available which contain further explanation on the use of RC circuits as filters. FILES NEEDED TO RUN LOW PASS FILTER GUI low_pass_filter.fig low_pass_filter.p RC.jpg Place these three files in the same directory, and make this your working directory in MATLAB. RUNNING THE LOW PASS FILTER GUI With the proper working directory selected, type 'low_pass_filter' in the MATLAB command window Fig. 1 shows the appearance of the GUI after it is first opened. There are initial values selected for the time constant and the excitation frequency. The excitation signal is a unit amplitude sine wave. These values can be changed by inputting a value manually by selecting the respective value field, or by using the respective slider bars. Low Pass Filter MATLAB GUI Documentation Rev 011705 1 Fig. 1. Low Pass Filter GUI. Fig. 2 shows the controls used to change the time constant and the excitation frequency, and the allowable range of values for these properties. Time Constant: 0.001 – .03 Excitation Frequency: 0 – 100 Fig. 2. Allowable input values for time constant and excitation frequency. For a given time constant and excitation frequency, two frequency domain plots are shown: the magnitude vs. frequency and phase vs. frequency, each plotted over a 100 Hz. range. The red line indicates the cutoff frequency, the black line indicates the input frequency. The time domain plot shows Low Pass Filter MATLAB GUI Documentation Rev 011705 2