On Jul 28, 12:21*pm, "Ed Huntress" wrote:


Engineers refer to a quadrature component in any case where there is
phase difference. *It's standard notation. *However slight the phase
difference is, a quadrature component is necessary to develop torque.

The engineers I know, and the electronics I learned when studying for both
my amateur and commercial radiotelephone licenses, mean a 90-degree phase
shift -- pi/2. Anything else is a phase shift of different proportions -- *
not quadrature.

What kind of engineers call any phase shift "quadrature"? Mathematicians use
different meanings for the term, referring to different processes of
integration, but I've never heard that usage in engineering applications.


Ed, you need to know more engineers. Any phase shift can be expressed
in terms of in phase and quadrature components. Take a look at

http://www.sciencedirect.com/science...e10117563240db

or just read this quote from there.

Abstract

The use of multiplier circuitry is shown to provide a simple way of
simultaneously measuring the in-phase and quadrature (phase-angle)
components of the signal in alternating current polarography. When
used with previously developed circuitry an extremely versatile
instrumental approach is available for detecting the second harmonic
and intermodular (frequency difference) components in addition to the
in-phase and quadrature components of the fundamental harmanic.

Dan