Home › Lessons › Network analysis › Thévenin equivalent

Thévenin equivalent

Network analysis · Advanced · about 20 minutes · part of Zen’s Electronics Design Mastery

Seen from its two output terminals, any linear network acts like one voltage source V_th in series with one resistor R_th. The lower circuit is that equivalent, and both drive the same load identically.

Thévenin equivalent: the circuit on the simulator's bench

Open this lesson in the labFree, in your browser, no account needed.

How it works

Vth = open-circuit voltage = Vs · R2 / (R1 + R2) = 8.25 V

Rth = resistance seen at a–b with the source shorted = (R1 ∥ R2) + R3 = 1.16 kΩ

Any load then gets VL = Vth · RL / (Rth + RL).

Try it on the bench

  1. With the switch open, V_ab reads V_th. Close it and compare V_ab with V_L’ below. They match.
  2. Change R_L and R_L’ to the same new value. They still match, for any load.

Parts on the bench

In the course

Zen’s Electronics Design Mastery, module “DC Circuit Analysis”.

More on network analysis