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Norton's theorem
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Equivalent current source with parallel resistor.
Equivalent to a current source I_N (short-circuit current) in parallel with resistance R_N = R_th. Related to Thevenin by source transformation.
V_th = I_N R_N.
Check which is easier.
In more detail
Norton's theorem states that any linear network can be replaced by a current source in parallel with a resistance. It is the dual of Thevenin's theorem.
Real-world uses
- Current source models of sensors and transistors use Norton equivalents.
- Analysing networks with many parallel branches.
- Engineers use a Norton equivalent to model a current source, such as a sensor, feeding a load.
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Frequently asked questions
How does it relate to Thevenin?
The Norton current equals the Thevenin voltage divided by the Thevenin resistance.
When is Norton more convenient?
When the circuit is naturally described by current sources.
How do Thevenin and Norton equivalents relate?
They are two forms of the same equivalent circuit, related by Ohm's law through the same resistance.
Related topics in Current Electricity & Circuits
Multimeter · Maximum power transfer · Thevenin's theorem · Superposition theorem · Delta–star conversion · RC circuit charging