Day 24 (Signals with Multiple Frequency Components Lab)

We started the day by discussing transfer functions which are essentially seeing how the output of a certain circuit element compares to the input of the circuit element. However the output of elements in circuits with AC current is dependent on the frequency of the source so the transfer function is a function of omega (w). Another difficulty of expressing the transfer function comes with working with complex functions with j and w tied together so we replace it with s. In this example we are concerned at what points does the transfer function go to zero and where the asymptotes are.

The transfer function can also be used to find the impedance of the section that we are curious in relative to the input of the circuit source by have the voltage across the section being divided by the input current. Again the transfer function will be a function of the function of the source and again the complex components are easiest to handle when they are replaced with a variable like s. The interesting locations are when the function is zero and has an asymptote.

We did one last transfer function for a series RLC circuit and calculated the voltage output of the circuit across the inductor against the input voltage. Again the important sections are when the transfer function gives us zero and an asymptote.

We then did the Signals with Multiple Frequency Components Lab and we started with the pre-lab. The pre-lab was to calculate what the response of the circuit across the second resistor would be as a transfer function. We then calculated the values at the frequencies 500Hz, 1000Hz, 10kHz.

Here are images of the circuit that was built.

Here are images of the oscilliscope graphing the input versus the output voltages. The difference in the images are the time divisions used for the horizontal axis.