I agree, I like to say "Back emf is our friend" .
Erfinder, said,
I take that to mean "Tune it to do what is desired".
..
What CEMF is exactly? I've yet to cross paths with one possessing the qualifications to even offer an honest opinion. Tons of good research has been going on over the years though. The mechanism associated with the production of this force is well known and established. The genius who coined the term "Inductance" whether known or unbeknownst to the individual at the time of penning the definition, reveals their supreme understanding and comprehension of the relation that this characteristic has to the generated force. Inductance is loosely (loosely equates to really simplified....) defined as being the opposition experienced when current in a conductor
starts,
stops or
changes. This definition should send chills down ones spine, and it usually does when you finally see whats being said. The funny thing about this is the author leads you to conclude that we are dealing with a characteristic, we know deep down that its anything but a characteristic. We fight with ourselves and our peers, refusing to accept what could be considered as truth, because there is no precedent for the assumption, an assumption we won't even entertain. So that I don't come across as a tease, I'll just state what we all should be considering.
Inductance = Magnetism
In light of this, parameter variation as its discussed in these circles needs overhauling.
Before those in the know went black, suggestions were begin made that all we need is to establish a difference in potential, for potentials move currents, those statements back then made no sense, what current? They make perfect sense now, found the current. Time passed as it generally does and folk stopped considering those statements, and the individuals making them moved on to simpler things, simpler demonstrations.
At any rate, CEMF is neither my friend nor my enemy, it is the soul of the apparatus, there to assist me in pinpointing the exact location, and the exact moment when change in the magnetic environs has taken place. It's present whether I want it there or not, serving its purpose, a function which, when reading some posts, is beyond the comprehension of the majority.
In my opinion, the machines as I have come to comprehend them are mechanisms through which counter electromotive force is magnified, magnified CEMF equates to magnified magnetism, whether you can put that magnetism to practical use is immaterial, the point is its presence.
As you didn't ask a question, you simply made a statement, I offer the following. Tuning is automatic, resonance is full spectrum. To tune as your tone suggests, suggests limiting the system to the frequency the operator has determined will be the frequency of lowest possible impedance. This is not what I am suggesting. I am suggesting that Nature in its infinite wisdom has a mechanism which when comprehended, makes all frequencies "the" resonant frequency. For this to function the circuit must behave as if it were both parallel and series resonant, both simultaneously and sequentially. Tesla suggested this if not in word, then most certainly in deed, the works speak for themselves.
Regards