Theorem Norton

Similar to Thevenin s theorem, Norton s theorem states that a section of a linear circuit containing one or more sources and impedances can be replaced with an equivalent circuit model containing only one constant current source and one parallel-connected impedance, as shown in Figure 2.36. 

Other methods to simplify the circuit are Thevenin s and Norton s theorems. These two theorems can be used to replace the entire circuit by employing equivalent circuits. For example, Figure 2.34 shows a circuit separated into two parts. Circuit A is linear. Circuit B contains non-linear elements. The essence of Thevenin s and Norton s theorems is that no dependent source in circuit A can be controlled by a voltage or current associated with an element in circuit B, and vice versa. 

The symbol with the two overlapping circles includes the battery or other power supply. The symbol with the upward arrow is used in theoretical work (regarding the Norton theorem, for example), but not usually in ordinary circuit diagrams. 

There are NEMD schemes where cause and effect are reversed the flux is imposed and the corresponding field is measured. Gonceptually this approach is based on the theorems of Norton and Thevenin which are an example of the macroscopic duality that exists between what are generally recognized as thermodynamic fluxes and thermodynamic forces. The principle of reverse perturbation has been used by Miiller-Plathe for calculating the shear viscosity, thermal conductivity, Soret coefficients, and thermal diffusion. For example, in the calculation of shear viscosity, the reverse nonequilibrium molecular dynamics (rNEMD) method involves a simple exchange of particle momenta the effect, the... 

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