Maximum power transfer

Monday, 20 August 2018

1:10 PM

Circuits are usually designed to provide maximum power to a load.

However, unlike ideal sources, the internal resistance of a real source restricts the amount of power that can be transferred to a load

The power consumption of that internal resistance is known as power loss

 

By using the Thevenin equivalent circuit we can find the maximum power that can be transferred to a load based on a fixed Thevenin voltage  and a fixed Thevenenin resistance  and a variable load resistance .

 

To find the value of  which would maximise the power, differentiate  w.r.t  and equate it to zero

 

 

Maximum power is transferred to the load when the load resistance  is equal to the Thevenin resistance  as seen from the load terminals