The main objectives of this lab
are to work through the procedural steps involved in Thevenin’s theorem, verify
the values obtained by measuring them using the multimeter, finally to
construct Thevenin equivalent circuit.
The equipment used in this lab:
· Regulated DC supply
· Resistors (100?( ´ 2),
7), 1.5k?, 2.2k?( ´
3), 3.3k?, 4.7k? and 10k?)
The theorem can be used to
analyse networks with sources that ae not in series or parallel and to minimize
the number of components required to put in place the same characteristics at
the output terminals. The theory behind this theorem is to simplify any complex
circuit. It expresses that for a linear electrical system any blend of voltages
sources, current sources and resistors with two terminals can be diminished to
one voltage source, one current source and one resistor since it is
electrically identical. However, when you simplify the circuit, some
calculations need to be done to obtain the values for the Thevenin equivalent
circuit. Firstly, we will need to remove that part of the network where the Thévenin
equivalent circuit is found. Afterwards, to calculate RTH we need to
set all sources to zero, that means that voltage sources need to be replaced by
short circuits and current sources by open circuits, then find the resultant
resistance between the two terminals. Then, to calculate VTH, we must
reset all the sources to their original state and then find the open-circuit
voltage between the marked terminals. Finally, to calculate the current we use
the formula .
to clarify the situation, Figure 1 is going to be our example.
theory is here to say that we can go from a difficult circuit to analyse to an
easy circuit to analyse.
This lab will help us
understand this theory more by proving Thevenin’s theory in a practical