### PHYS 415 Electronics

#### Lab 1 Network Theorems

In this lab we will analyze the circuit shown in Figure 1 using the following;

Figure 1 |

- Kirkoff's node law
- Kirkoff's loop law
- Superposition
- Thevenin's Theorem
- Norton's Theorem

#### Kirkoff's node law

*The sum of the curents flowing into a node is zero.*

With the output current I_{out} equal to zero, write an equation for the total current flowing into the node labeled V_{out}. Solve for V_{out}.

#### Kirkoff's loop law

*The sum of the voltages around a loop is zero.*

Again with the load disconnected (I_{out} = 0.)
Add the voltages arround the outer loop (10V plus the voltage across R_{1}
and R_{2}). Assume a current I_{1} flowing clockwise around the
first loop(Through the 10V supply, R_{1} and the 2mA current source.)
Also assume a current I_{2} flowing clockwise around the second loop (the 2mA current source and R_{2}.) Note that 2mA = I_{2} - I_{1}.

Solve for I_{2} and for V_{out}.

#### Superposition Theorem

*In a linear system the effect of a number of causes is equal to the sum of the effects of each cause acting individually.*

Set the current source equal to zero (no current-open circuit). Solve for V_{out} due to the 10V voltage source. Set the voltage source equal to zero (no voltage-short circuit). Solve for V_{out} due to the current source. Add these two componets of V_{out} to find V_{out}.

#### Thevenin's Theorem

*As seen from a terminal, any linear network appears to be a voltage source in series with a resistor.*

Obtain theThevenin equivalent circuit for the crcuit shown in Figure 1 as seen from the V_{out} terminal.

Figure 2 Circuit under test and its Thevenin equivalent

#### Norton's Theorem

*As seen from a terminal, any linear network appears to be a current source in parallel with a resistor.*

Obtain the Norton equivalent circuit for the crcuit shown in Figure 1 as seen from the V_{out} terminal.

Figure 3 Circuit under test and its Norton equivalent

Simulate the circuit in Figure 1 using PSPICE.

Obtain plots of the output voltage V_{out} as a function of output current for the circuit and its Thevenin and Norton equivalents.

Breadboard the circuit. Take measurements to verify network theorems.