Time varying signals

We started class with time varying lab

Pre lab: we draw three graphs of the following circuit using input and output voltages . The shape was the same but amplitude was half. 

Following are the screen shot of waveform in sinusoidal , triangle and square wave form. The basic shapes of these signals are all periodic signals. They repeat themselves at regular intervals. The amplitude of the signal is essentially he maximum and minimum value that the signal achieves.




Frequency: 1ms
Amplitude: 2V

Frequency : 2ms

Amplitude: 4.5V

Frequency: 1ms

Amplitude 3V

LAB: A BJT curve Tracer

The purpose of this lab is to investigate the collector current, I_C vs. collector voltage, V_CE characteristics of the BJT. After successfully configuring the curve tracer, we serialized and measured the device and sorted this inventory of transistors by various parameters such as 

Following is the image of our gummel plot data and graph. The Gummel plot is the combined plot of the collector and base currents (I_C and I_B) of a transistor vs. the base-emitter voltage, V_BE, on a semi-logarithmic scalegain (beta) , V_BE etc

Set up of BJT curve tracer circuit

Then we learned about linear circuits. Following an example of linear circuit that we did in class. A linear circuit is one whose output is linearly related to its input. 

Superposition : The superposition principle states that the voltage across (or current through) an element in a linear circuit is the algebraic sum of the voltages across (or currents through) that element due to each independent source acting alone.
Following is an example of superposition problem we did in class. 

Then we learned about source transformation : following one problem that we did using source transformation . A source transformation is the process of replacing a voltage source  V in series with resistor R by a current i in parallel with a resistor R or vise versa.