# Very Simple Tutorial on Thevenin Theorem.

In this tutorial, we are going to learn about Thevenin Theorem.

Thevenin Theorem Circuit – In this circuit, A linear and bidirectional two terminal network can be replaced by an equivalent network consisting of a voltage source VTH connected in series with a resistor RTH.

Here VTH & RTH. :

VTH – Open circuit voltage at the terminals.

RTH  – Input / Equivalent resistance at the terminals when the independent source are turned OFF.

Main Point of Thevenin Theorem.

• It is always work in open circuit.
• Its voltage source use in open circuit where internal impedance is low.

Here we are taking example for Thevenin Theorem.

As per below circuit for Thevenin Theorem, Here we will calculate the circuit value as per Thevenin Theorem.

As per below circuit , Now we will calculate the total current flow in circuit .

As per OHM’s Law V = RI , I = V/R

IS = E / (ZS + Z1)  + / Z3(Z2 + ZL) / (Z3 +Z2 + ZL)

In this circuit, Current flow in Z3, (IS – IL)

Now we will calculate the Load current in circuit.

IL (Z2 + ZL)=  (IS – IL) Z3

IL Z2 + IL ZL =  IS Z3 – IL Z3

IL (Z2 +  ZL  + Z3 )=  IS Z3

IL = IS Z3 / (Z2 +  ZL  + Z3 )

Now

IL =  Z3 / (Z2 +  ZL  + Z3 ) x E / (ZS + Z1)  + / Z3(Z2 + ZL) / (Z3 +Z2 + ZL)

IL =  EZ3 / (ZS + Z1) (Z3 +Z2 + ZL) + / Z3(Z2 + Z1)

IL =  EZ3 / (ZS + Z1+Z2) {Z2 + ZL) +   Z3 / (ZS + Z1) / (Z3 + ZS + Z1)

IL =  EZ3 / ZS + Z1+Z2 /  {Z2 +   Z3  (ZS + Z1) / (Z3 + ZS + Z1) + Z2

IL  = EEQ / ZEQ +ZL 