INC 112 Basic Circuit Analysis Week 6 Other Techniques

Special Techniques Superposition Theorem Thevenin’s Theorem Norton’s Theorem Source Transformation

When we do not need to know the current and the voltage inside the box, we can interchange the circuit inside without affecting other parts in the circuit.

Example Use source transformation to find Ix

I V V OC I SC Maximum Power Theorem High RL: high voltage, low current Low RL: high current, low voltage

Maximum Power Theorem From Thevenin or Norton equivalent circuit, the RL that gives the maximum power is RL that equals Rth. RL that gives the maximum power is RL = Rth

Proof where Substitute in the equation

Therefore, RL = Rth is the point that yields maximum power Find the first derivative. Let it equal zero to find critical points.

Example Find RL that gives the maximum power and find that power.

Thevenin’s equivalent circuit RL that gives the maximum power is 13.2Ω Maximum Power is

Voltage Sources in Real World I V I V Ideal Voltage Source Real Voltage Source

Current Sources in Real World I V I V Ideal Current Source Real Current Source

Delta-Wye Conversion (∆-Y)

Example