DC Network Theorems Unit 9 – Thevenin/Norton Conversion
UNIT 9 – THEVENIN/NORTON CONVERSION
UNIT OBJECTIVE
At the completion of this unit, you will be able to convert networks into equivalent voltage and
current sources by using Thevenin's and Norton's theorems.
UNIT FUNDAMENTALS
You can use Thevenin's theorem to reduce a network into an equivalent circuit called a voltage
source. VTH is the voltage source. RTH is the internal source resistance. Terminals A and B are
the output terminals of the source.
In a practical circuit, the no-load output voltage equals VTH. When a load (RL) is connected
across terminals A and B, the output voltage equals VTH - VRTH because RTH and RL form a
voltage divider.
You can use Norton's theorem to reduce a network into an equivalent circuit called a current
source. IN is the current source and is represented by an arrow in a circle. RN is the internal
source resistance. Terminals A and B are the output terminals of the source.