Re: 1994 article

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

"Phasor analysis was developed essentially by Charles Proteus Steinmetz,
that published the first description of the method by 1893.

>I did a Google and was surprised that Mr. Laplace presumably the inventor
>(or did he discover) of Laplace Transforms lived 1749-1827.
>Almost 200 years ago !!!!

It's not clear to me from where the use of Laplace transforms in
circuit theory come. It may have been just an application of
a known method to linear circuits, or a reinvention, later recognized
as being something already known. I think that the use of Laplace
transforms in circuit theory become common practice from around
1924, with the work of R. M. Foster about reactance synthesis,
but it was probably used before.

Antonio Carlos M. de Queiroz"

	When I attended the University of Missouri engineering school Laplace
transformers were not yet taught and we used Heaviside's methods for
transient analysis, which was more awkward.  I'm sure less backward
schools had been teaching Laplace transformers for that purpose many
years earlier.  We did use phasors and "vector diagrams" in classes on
AC circuits and machinery but somehow the presentations were excessively
involved and sort of covered up the beauty of the methods. By that time
Steinmetz's "quarter phase components" had been renamed imaginary or
quadrature components.

	As far as I can tell, none of my fellow engineers really understand
phasors and their use for visualizing problems.  Pity as they are very
useful, particularly in understanding digital filtering and "I/Q"
components of signals.

Ed