Norton’s Theorem. By: Engr.Irshad Raheem Memon PRACTICAL # 07 Norton’s Theorem. By: Engr.Irshad Raheem Memon

OBJECTIVE Objective of this practical is to learn about Norton’s Theorem; and how this theorem is used to convert a complex resistive DC circuit into Norton equivalent circuit.

What is Norton’s Theorem Norton’s theorem provides a method for simplifying any two terminal complex resistive DC circuit to an standard equivalent form. Norton’s equivalent circuit consists of an equivalent current source and a resistor in parallel

Norton equivalent circuit is shown in figure 01.

Description Continued… Norton equivalent current is the close circuit (no load) current between two output terminals A & B in a circuit. Norton equivalent resistance is the total resistance appearing between two output terminals A & B in a given circuit with all sources replaced by their internal resistances.

Continued… Norton’s equivalent circuit acts same in terms of output voltage and current as visualized in figure 02.

Steps for applying Norton’s theorem: Step 01: Short the two terminals (remove any load) between which you want to find the Norton equivalent circuit Step 02: Determine the current (IN) through the two shorted terminals Step 03: Determine the resistance (RN) between the two open terminals with all sources replaced with their internal resistances. Step 04: Connect IN and RN in parallel to produce the complete Norton equivalent circuit for the original circuit. Step 05: Replace the load removed in Step 01 across the terminals of the Norton equivalent circuit. You can now calculate the load current and load voltage using only Ohm’s law. They have the same value as the load current and load voltage in original circuit.

Coming Towards Objective Now

REQUIRED APPARATUS Multism Software Resistors Bread board Multimeter DC voltage source Connecting wire etc

PROCEDURE Realize the circuit on breadboard as shown in figure 01(a)Find out voltage across and current through terminals A & B in original circuit. Then convert this circuit into Norton equivalent circuit by following the steps of Norton’s theorem. IN and RN for original circuit can be found as given in figure 03.

STEP 01 Short the two terminals (remove any load) between which you want to find the Norton equivalent circuit

STEP 01 Circuit on MULTISM

STEP 02 Determine the current (IN) through the two shorted terminals

STEP 02 Circuit on Multism

STEP 03 Determine the resistance (RN) between the two open terminals with all sources replaced with their internal resistances.

STEP 03 Circuit on Multism

STEP 04 Connect IN and RN in parallel to produce the complete Norton equivalent circuit for the original circuit.

STEP 05 Replace the load removed in Step 01 across the terminals of the Norton equivalent circuit. You can now calculate the load current and load voltage using only Ohm’s law. They have the same value as the load current and load voltage in original circuit. Now To Prove Results. We have to prove that Output Voltage and Current of Original Circuit must be Equal to Norton Output Voltage & Current

STEP 05 Circuit on Multism

Prove All Results Above Manually

Observation:- Value of current through and voltage across terminals A & B in both original and Norton equivalent circuit is same.

ANY QUERY