"Don Foreman" wrote in message
...
On Wed, 28 Jul 2010 12:21:12 -0400, "Ed Huntress"
wrote:


"Don Foreman" wrote in message
. ..
On Tue, 27 Jul 2010 14:19:15 -0400, "Ed Huntress"
wrote:

But it was
apparent to me from the time you first commented that you must have been
absent the day they explained internal phase relationships and force in
single-phase motors. g You went so far off base, contending that those
motors operate in quadrature and so on (most inentionally do *not*
operate
in quadrature; it's part of their design to have partially-shifted
phases)
that I didn't even respond to much of it.

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.

Any phasor may be thought of as having two components, i and q,
inphase and quadrature. The resultant, or phasor, is the vector sum
of the two components. For a phasor of magnitude M at phase angle a,
i = M cos(a) and q = M sin(a).

What kind of engineers call any phase shift "quadrature"?

No kind. From above: "Engineers refer to a quadrature component in
any case where there is phase difference."


Right. Except, perhaps, for Dan's Australian friends. g That's why I said
that most single-phase motors do not run with an induced, second phase that
is in quadrature. The second phase can be at a wide variety of phase angles,
and many single-phase motors are made specifically to produce a second phase
that is NOT 90 degrees out of phase with the primary phase. It has to do
with producing better starting torque, but I forget the details.

I said this was a "partially shifted" phase, or something like that, in our
original discussion. That's exactly what it is. And you jumped all over me
for being an ignorant writer. g

--
Ed Huntress