Thursday, May 28, 2015

Frequency dependence


Today we start off the class with learning about Frequency dependance and transfer functions.
The frequency response of a ciruit is the variation in its behavior with change in signal frequency.
The frequency response of a circuit may also be considered as the variation of the gain and phase with frequency.

The transfer function H(ω) (also called the network function) is a useful analytical tool for finding the frequency response of a circuit.

We did following problem in class to calculate gain and poles



In following problem we calculated transfer impedance function



we used Free mat to calculate and see the graph function



we got following graph from our function



Signals With Multiple Frequency Components Lab 
In this lab we found the magnitude response of an electrical circuit and use this information to infer the effect of the circuit on some relatively complex input signals. 
PRE LAB CALCULATIONS


above circuit acts like DC in low frequency, so when the capacitor is open, the voltage across R2 should be half of Vin. 

At high frequency, the circuit acts like AC, so capacitor acts like short, and voltage across R2 is 0. which  means that as omega goes to 0, Vout also goes to 0. It is a low-pass filter, meaning low frequencies flows through while high frequencies are blocked.

Fllowing is the the circuit we built on breadboard using 2 R of 1K ohm , 1 Capacitor of 100nF and wires


Input voltage : 20{sin(1000*pi*t)+sin(2000*pi*t)+sin(20000*pi*t)}:

voltage across the resistor . vout is orange and V in is blue which shows the rise of output voltage and fall with input

Part 2 of lab:

Input voltage from 100 Hz, 10 Khz

output graph 100 Hz


Both graphs were  within expected rate. 

Today we learned about transfer function and calculate gain and poles. 






No comments:

Post a Comment