Sujet : Re: rod-mill project - "mains" electric motor advice
De : muratlanne (at) *nospam* gmail.com (Jim Wilkins)
Groupes : rec.crafts.metalworkingDate : 22. Apr 2025, 12:54:03
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vu801e$gq7a$1@dont-email.me>
References : 1 2 3 4 5 6
User-Agent : Microsoft Windows Live Mail 16.4.3505.912
"Richard Smith" wrote in message
news:m1r01kwsh9.fsf@void.com...P=power (Watts)
tau = torque (Newton.metres)
omega = rotation-rate (radians/s)
Latter makes total sense - well it does for me :-) Radian is where a
radius is wrapped around the circumference. Very often gives vast
simplifications (compared to working in angular Degrees or Revs Per
Minute, etc.).
------------------------------------
I took night school classes to keep up with my day job. The analytic geometry teacher gave many practical hints that made working with sines and cosines simple, but in Degrees. For me learning advanced math from night school teachers who used it as a tool in their day jobs was much easier than from those in college who considered it an abstract art form. In night school I aced calculus classes I'd barely squeaked through in college. I was probably correct to take chemistry which I could pass instead of more mathematical electrical engineering. DC isn't bad, AC requires advanced calculus.
Phase modulation for digital radio employs similar trigonometry but in Radians, expressed as a multiple of pi, 2*pi being a full circle. I struggled to quickly mentally convert between 45 degrees and pi/4 etc, also between decibels and voltage, when listening to explanations of what an engineer wanted me to build or interpreting an instrument display.
https://en.wikipedia.org/wiki/Phase-shift_keyingThat and especially the error correction schemes were among the most difficult subjects I ever encountered, since I had lost my way while studying Laplace Transforms in college. Segway motor drives used similar math, based on the "imaginary" square root of -1 defining an orthogonal axis for "imaginary" capacitive and inductive current and voltage. Complex numbers that initially seemed useless to me are a perfect fit.
https://www.egr.msu.edu/~wierzba/steinmetz.pdf"His paper on complex numbers revolutionized the analysis of ac circuits, though it was said at the time that no one but
Steinmetz understood the method."
https://www.smithsonianmag.com/history/charles-proteus-steinmetz-the-wizard-of-schenectady-51912022/