advertisement

Norton Equivalent Circuit Norton’s Theorem Any two-terminal linear network, composed of voltage sources, current sources, and resistors, can be replaced by an equivalent two-terminal network consisting of an independent current source in parallel with a resistor. Network of Sources and Resistors Norton equivalent circuit . + Arbitrary Network v b IN IN isc RN . a Network of Sources and Resistors ob isc . IN = isc b isc = IN RN oa + RN = RTh VTh IN = RTh Arbitrary Network v b Finding IN and RN (II) RTh IN RN . oa VTh a + . Finding IN and RN (I) We can derive the Norton equivalent circuit from a Thevenin equivalent circuit simply by making a source transformation . i i a IN RN voc - ob . a Network of Sources and Resistors + RN = voc . - voc IN b voc = RNIN 1 Summary To determine the Thevenin or Norton equivalent circuits, we need to calculate any two of the following three: • voc • isc • Req Example Determine the Thevenin and Norton equivalent circuits at terminals a-b of the following circuit. If a load with RL=10 Ω is connected across terminals, what’s the power delivered to the load? What is the power if RL=22.5 Ω and RL=50 Ω ? VTh = voc IN = isc RTh = RN = voc isc 2