The Norton equivalent circuit
The Norton's Theorem is similar to the Thevenin's Theorem.

It can be seen that the equivalent circuit is:
A Voltage source (Thevenin voltage: Vth) in series with a resistor (Thevenin resistance: RTH)
The Norton's theorem says that the equivalent Norton circuit is a combination of a current source in parallel with a resistor
It is easy to find the Norton equivalent circuit when we have the Thevenin equivalent circuit by using the following formulas:
- Current source: IN = Vth/Rth
- Resistor: RN = Rth
Note: You may obtain the Thevenin equivalent circuit from the Norton equivalent circuit, using the following formulas:
- Voltage source: Vth = IN * RN
- Resistor: RTh = RN