Source transformation
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A source transformation is the application of Thevenin's theorem to a current source, or Norton's theorem to a voltage source.
Specifically, source transformations are used to exploit the equivalence of a real current source and a real voltage source, such as a battery. Application of Thevenin's theorem and Norton's theorem gives the quantities associated with the equivalence. Specifically, suppose we have a real current source, which is an ideal current source in parallel with an impedance. If the ideal current source is rated at I amperes, and the parallel resistor has an impedance Z, then applying a source transformation gives an equivalent real voltage source, an ideal voltage source in series with an impedance. In this source, the ideal voltage source has a value equal to the ideal current source's value times the resistance contained in the real current source (
). The impedance component of the real voltage source retains its real current source value. This procedure is reversible, and can be summarized by keeping two things in mind:
- Ohm's Law (
) - Impedances remain the same
