Ect 122 W7

Thevenin’s Theorem

1. What is Thevenin’s theorem? What purpose does it serve?

Thevenin’s Theorem states that any resistive circuit, no matter how complex, can be represented as a voltage source in series with a source resistance. It is used to simplify a circuit for easier analysis.

2. What is VTH ? How is it measured?

VTH is Thevenin’s Voltage, and represents the voltage present at the output terminals from which a load is removed.

3. What is RTH ? How is it measured?

RTH is Thevenin’s Resistance, and represents the resistance measured across the output terminals with the load removed

4. Given the circuit below, determine the Thevenin equivalent voltage and resistance.

VTH = 7.3V

RTH = 88Ω

5. Download the Multisim file “Thevenin1” from Doc Sharing, week 7. Run the simulation and verify the simulated results are the same as the calculated values. Were the values the same? YES/NO. If No, why?

6. Build the original circuit in question 4 on a breadboard. Connect the circuit’s input to the power supply and set it to 10V. Use the hand held DMM to adjust the supply to the accurate value. Measure the load voltage using the DMM. Have the professor verify the circuit before applying power. Measure VL1 and note below.

VL1 = 6.13V

7. Construct the Thevenin equivalent circuit for the circuit above on a breadboard. Connect the circuit’s input to the power supply and set it to VTH. Use the hand held DMM to adjust the supply to the accurate value. Measure the load voltage using the DMM. Have the professor verify the circuit before applying power.

VL1,Thevenin Equivalent = 6.17V

Does the measured Thevenin voltage match the output voltage from the original circuit? Yes/No. If No, determine why and correct the problem.

I had to use an old headlight switch with a pot to create the 88Ω resistance