Keith Dysart wrote:
On Apr 27, 9:22 pm, Cecil Moore wrote:
Owen Duffy wrote:
Isn't hopping onto the rotor (assuming synchronous speed) to make your
observations called moving from the time domain to the frequency domain,
and all the mathematical shortcuts are only valid if all quantities share
the same angular velocity (or frequency), implying sinusoidal waveform.
Ever wonder which direction, clockwise or counter-clockwise,
a standing-wave phasor is rotating?

Clockwise, of course, by convention. Always look at the end of the
machine that lets you draw your phasor diagram clockwise.

The equation for a standing wave,

E(x,t) = 2*Eot*sin(kx)*cos(wt)

would have an identical value if it were written,

E(x,t) = 2*Eot*sin(kx)*cos(-wt)

Thus, a standing wave phasor can be considered to be
rotating either clockwise or counter-clockwise.
--
73, Cecil http://www.w5dxp.com