Thevenin Equivalents

Motivational Analysis Problem:

Design a circuit that runs off of two regulated power sources which must supply a certain voltage across a load. Also, consider what voltage will exists at the terminals at the load if the load is removed and what the short circuit current would be there.

PSpice Thevenin and Max Power (Homework)

Here we used PSpice to answer a few homework problems.

Below is a graph made by running a simulation of the above circuit. The vertical intercept of 96.61V is the Thevenin Voltage. The slope of around 5.333 gives the Thevenin Resistance.

Below is the 2nd problem.

Once again, the intercept of 53.18V gives us our Thevenin Voltage and the slope of 50.9 gives us our Thevenin Resistance.

I created a simple representation of the circuit using the Thevenin equivalents and ran an analysis in order to determine what load resistance allows the greatest total power. A load resistance of 50.9 Ohms gives the greatest power of 13.9 W.