Reference no: EM132416169

Laboratory Assignment - Thevenin and Norton Equivalent Circuits

Department of Electrical Engineering - University of North Dakota, USA

Purpose - The objective of this laboratory is to experimentally determine the Thevenin equivalent circuit of a resistive network driven by a DC voltage source, as well as the parallel current and resistance for the corresponding Norton equivalent circuit. Both the Thevenin and Norton equivalent circuits are depicted in Figure 1. The maximum power transfer theorem will also be verified empirically.

Procedure -

First design a circuit that looks like the one shown in Figure 2, that will have a Thevenin resistance of 3.9 k?, be sure to not use any resistors that you used in your pre-lab, except that of the load resistor. Measure the experimental values of all resistances in the circuit shown in Figure 2 before they are placed into the circuit. Measure and record the voltage across every element and the current flowing through every element.

Parameters for the Thevenin and Norton equivalents will be measured for the circuit to the left of the load resistance, RL. Since we need the open circuit voltage, voc, and the short circuit current, isc, to calculate all relevant parameters, be sure to measure these quantities as shown in the Figure 3 schematics below.

We are also able to calculate the Thevenin (and Norton) resistance directly by turning off all independent sources and measuring the equivalent resistance of the network. Measure the Thevenin resistance, RTh, to the left of terminals a-b in Figure 4.

We will now empirically verify the maximum power transfer theorem by measuring the power dissipated by the load over a range of resistance values. Choose ten resistors for RL, from 0 Ω to 5.6 kΩ, in the complete circuit. Measuring the power dissipated by the load for each resistor value. What value of R provides maximum power transfer to the load? Does this agree with your theoretical expectations?

Laboratory Report -

Provide all measured resistance, voltage, current, and power values. You must perform a theoretical analysis of the complete circuit, providing theoretical values for the open circuit voltage, the short circuit current, and the equivalent resistance to the left of the output terminals with the DC independent voltage source turned off.

Using measured resistance values, compute the theoretical value of the load resistance which provides maximum power transfer to the load. Provide an experimental plot of power dissipated by the load resistance versus load resistance value. Which resistance value results in maximum power transfer?

Make sure that you plot the values using a Microsoft Excel spreadsheet. Excel will automatically interpolate the measured data points, resulting in a smooth power dissipation curve. You may wish to perform a least squares fit on the experimental data points in Excel, in order to estimate the true value of the load resistance which maximizes power.

Please generate your laboratory report in the proper format. The report contents must include the data obtained in the laboratory (measured resistance, voltage, current, and power values in a table format), all required theoretical analyses, an error analysis, and answers to questions within this handout.

Note - All figures are in attached file.

Attachment:- Thevenin and Norton Equivalent Circuits Assingment File.rar