6_Postlab

# 6_Postlab - NOTE MATLAB step and bode commands If you have...

This preview shows page 1. Sign up to view the full content.

ME 365 POSTLAB EXERCISE FOR LAB 6 FALL 2011 In order to reduce the noise level of a CD player, the engineers have decided to use a simple RLC circuit to filter out the high frequency noise. The RLC circuit we plan to use as the low-pass filter should have a frequency operating range up to 15 kHz, which is defined as 70.7% value of the magnitude of the low frequency . It should also have a damping ratio of 1/ 3 in order to avoid unwanted amplification due to the resonant peak of the frequency response. To minimize cost, we would like to use our in-stock inductors of 0.02 H. 1) Choose a capacitor and a resistor to achieve the desired filter. Write down detailed calculations. 2) Attach a step-response plot of the RLC circuit and a Bode plot of the frequency response function of the RLC circuit using the component values that you have specified.
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: NOTE: MATLAB step and bode commands If you have a frequency response function of the form: Y j b 1 j b o a 2 j 2 a 1 j a o Take all of the “jω” terms and replace them with something else, for example, “s,” so that: Y s b 1 s b o a 2 s 2 a 1 s a o Now, you can use this function to generate a bode plot and step response of your Y(jω) function in MATLAB. Simply define some variable—“sys” for example—and use the step and bode commands as follows: >>sys = tf([b 1 b o ] , [a 2 , a 1 , a o ]) >>step(sys) >>bode(sys) Try entering the example below for b 1 = 0, b o = 1, a 2 = 1, a 1 = 2, and a o = 3, and see what you get. Use this method to make Bode and step response plots for this post-lab. Do not forget to label your axes of your step response! >> sys = tf(1, [1, 2, 3]); >> step(sys) >> bode(sys) R L C V in (t) V out (t)...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online