THEVENIN EQUIVALENTS

-----INTRO-----

Given a minimum acceptable voltage across Load #2, determine the smallest equivalent Load #2 resistance that can be successfully used.

Use the Thevenin process to reduce part of the network down to an equivalent source and series resistance.

The image below is a closer look at the circuit that we will be working with:

It consists of 2 power sources (volts) and 4 resistors of various resistance.

-----CALCULATIONS-----



 

NOTE: Vx=Vth, knowing this and using nodal analysis allowed us to come up with an answer for the thevenin voltage, 8.64V! Then we removed the power sources to calculate the thevenin resistance, 65.94Ohms!

The completed thevenin circuit is pictured above.

The calculations include an 8V because the experiment is asking for the load required when 8V are applied. We were able to conclude our Rload of 824.40V by using Voltage Division.

-----EXPERIMENT-----

 

 The Set Up

Resistors used: 100Ohms, 2 x 39Ohms, 680Ohms

Voltage (power supply): 2 x 9Volts

Measurements:

(Notice there is only minimal error making us comfortable to continue)

The next step asked for us to disassemble our thevenin circuit to test the original circuit so we could compare them two.

First, verify max power:

R12 was set to equal 0.5RTh

This experiment demonstrated the resemblance that a thevenin circuit, calculated properly, can work as an equivalent to an original circuit. Sometimes it is recommended since the circuit becomes a little simpler to work with.