lcapy.phasor

This module provides the PhasorDomain and PhasorRatioDomain classes: to represent phasors and ratios of phasors for AC analysis.

A phasor represents the amplitude and phase for a single sinusoid. By default the angular frequency is omega_0 but it can be any number or symbol.

Phasors straddle the time and frequency domains and hence the confusing phasor classes.

A phasor is described by an amplitude and phase. There is also an implicit frequency. The amplitude and phase are usually functions of frequency. A phasor is useful to describe an AC voltage or current signal.

Lcapy considers V(jw) or I(jw) a generic phasor but V(3j) or I(3j) a specific phasor. Similarly, X(jw) is a generic phasor ratio and X(3j) is a specific phasor ratio, where X denotes an immittance or transfer function.

A ratio of two phasors (of the same frequency) is not a phasor. The ratio of two generic phasors is a frequency domain quantity. The frequency dependence is explicit. A phasor ratio is useful to describe an immittance or transfer function. These are frequency domain concepts. A phasor ratio can be inferred from the Laplace domain by substituting jomega (or jw) for s, where omega is the angular frequency of the phasor.