Download Norton and Thévenin Theorems Part 1-Basic Electronics-Lecture Slides and more Slides Fundamentals of Electronics in PDF only on Docsity! Lecture Seventeen Norton and Thévenin Theorems The Thévenin theorem states that We can replace the entire network exclusive of load with an equivalent circuit containing independent voltage source (VTh) with a series resistor (RTh) in such a way that the current‐voltage relationship across the load remain unchanged. The Norton theorem is essentially the same except that the independent voltage source and series resistor is replaced with independent current source (IN) and a parallel resistor. Problem solving strategy: • Remove the load and calculate the Voltage VTh at these open circuited terminals by applying all circuit analysis techniques (KVL, KCL, loop and node analysis, Ohm’s law, voltage and current division). • For circuit with independent sources only, determine RTh by open circuiting all current sources and short circuiting all voltage sources and calculate the equivalent resistance RTh using series‐parallel combination of pure resistive network. • Thévenin equivalent circuit consists of independent voltage source VTh and a series resistor RTh. • For Norton Equivalence, convert the Thévenin equivalent to Norton equivalent through simple source transformation. INDEPENDENT SOURCES Example: Calculate V0 using Thévenin theorem Since we want to calculate V0 across 8 kΩ resistors, we remove it. Since there is no current across 4kΩ so in this case RL = 8k + 4k Ω. + V 0 - docsity.com Removing the load and using simple source transformations and adding algebraically the sources 8 2m 4k 16V 4kTh V ⎛ ⎞= + × =⎜ ⎟ ⎝ ⎠ By short circuiting the 12 V supply and open circuiting the 2 mA source, we get 3 63k 6k 2k 2 4k 3 6Th R ×= Ω Ω+ Ω = + = Ω + With Thevenin Equivalent Circuit to load again, we can calculate V0 through voltage division 0 8k 8V 8k 4k ThTh V V R = = + + Example: 1. Calculate V0 using Thévenin theorem. 2. Confirm your result through Norton’s principle. 3. Calculate the power transferred to load resistance. 4. What should be the load resistance to be replaced with 6kΩ so that maximum power is transferred? Thévenin Theorem: In this case 6 kΩ is designated as RL docsity.com
