Duality (electrical circuits)
Appearance
In electrical engineering, electrical terms are associated into pairs called duals. A dual of a relationship is formed by interchanging voltage and current in an expression. The dual expression thus produced is of the same form, and the reason that the dual is always a valid statement can be traced to the duality of electricity and magnetism.
Here is a partial list of electrical dualities:
- voltage – current
- parallel – serial (circuits)
- resistance – conductance
- impedance – admittance
- capacitance – inductance
- reactance – susceptance
- short circuit – open circuit
- Kirchhoff's current law – Kirchhoff's voltage law.
- Thévenin's theorem – Norton's theorem
History
The use of duality in circuit theory is due to Alexander Russell who published his ideas in 1904.[1][2]
Examples
Constitutive relations
- Resistor and conductor (Ohm's law)
- Capacitor and inductor – differential form
- Capacitor and inductor – integral form
Voltage division — current division
Impedance and admittance
- Resistor and conductor
- Capacitor and inductor
See also
References
- Turner, Rufus P, Transistors Theory and Practice, Gernsback Library, Inc, New York, 1954, Chapter 6.