Circuit Theory #30 | Maximum Power Transfer - Find RL and Pmax

Instructor: Dr. Süleyman Burak ÇELİK

Thirtieth lesson in the Circuit Theory series. This lesson introduces maximum power transfer for a resistive load connected to a Thevenin equivalent, then solves a full example step by step. Main question: What value of `RL` makes the load receive the largest possible power? Worked steps: - Explain the voltage-current tradeoff in the load - Build the load power formula from `i = Vth / (Rth + RL)` - Derive the maximum power condition `RL = Rth` - Use `Pmax = Vth^2 / (4Rth)` - Example: turn off independent sources and find `Rth = 9 ohm` - Open the load and use nodal analysis to find `Vth = 22 V` - Compute `RL = 9 ohm` - Compute `Pmax = 22^2 / (4 * 9) = 13.44 W` Key idea: For maximum load power, match the load resistance to the Thevenin resistance seen from the output terminals.