Maximum
power transfer theorem is used to find the value of load
resistance for which there would be maximum amount of power transfer from
source to load.
Maximum power transfer theorem is stated as “ a resistive load, connected to a dc network, receives
maximum power when the load resistance is equal to the internal resistance of
the source network when seen from the load terminals”.
Maximum power transfer theorem for DC circuits proof :-
Let a variable resistance RL be connected
to a dc network as shown.
Here our aim is to find the value of RL for
which it receives maximum power from the dc source.
From the figure
While the power delivered to resistive load is
Here, since only RL is variable, therefore,
PL can be made maximum by
varying RL
∴ maximum power can be
delivered when
What is the value of maximum power
transfered ?
What will be the efficiency at the time
of maximum power transfer ?
The maximum power transfer theorem has wide application in communication circuits and a transformer is used many times to match source impedance to load impedance.
The above concept of maximum
power transfer theorem can be extended to ac circuits. How will load impedance
become equal to source impedance ?
by making the load impedance the
complex conjugate of the source, right ? read Maximum power transfer theorem for AC
Closely related concept :-
