EDIT -- Thank you for re-writing your paragraph. Since other posts appeared while i was typing, I tried to quote the first two lines but apparently we can't "Quote" in edit mode.
I wasn't ignoring you, it took me about an hour to type this so i missed a lot of the conversation.
...........................
That's a LOT BETTER! Thank You !
tor2006 said:
I know where I made a mistake
First step toward understanding ...
tor2006 said:
The current generates a magnetic field .
To one way of thinking there are two magnetic fields in a motor. That of the stator and that of the rotor. They can attract or repel to do mechanical work.
tor2006 said:
if we do a useful work with that magnetic field we converted the energy .
Yes.
tor2006 said:
For electric motor is important that the current passes through the windings so it does not care about where electrons "leave "energy .
There may be more than one winding. The magnetic field that enables energy conversion mihgt be created by an electromagnet or by permanent magnets.
The winding where the actual conversion between mechanical and electrical energy takes place is called the "Armature" and that's where the Lorentz force makes that conversion .
In the examples above the moving conductor is the armature.
The magnetic field through which it passes might be made by an electromagnet or by a permanent magnet.
Whatever produces it is called "The Field".
If "The Field" is an electromagnet its windings are called "Field Windings".
The windings of the armature are of course called "Armature Windings" .
Now, that's vocabulary. It is important to use terms that lead the mind toward the correct concept.
Else we will mis-communicate."...so it does not care about where electrons "leave "energy..."
It makes a big difference where the electrons 'leave' (is 'deposit a better word?) their energy.
If they expend their energy hopping between copper atoms, that just heats the armature wires instead of making useful work.
If they expend their energy overcoming Lorentz force then they have exerted torque on the shaft and done useful work.
tor2006 said:
Copper losses reduce the magnetic field and thus reduce useful work .
Heat doesn't reduce a magnetic field.
That's the trouble with words - our mind will believe a sentence that's grammatically correct but physically wrong.
Resistance of armature wires limits (or reduces) the current available to make torque.
What is going on in the armature is the force on the charges that are moving along the wire cause torque as explained above.
Resistance only limits the rate of charge movement.
Lorentz force acts in a second way once the armature starts to rotate.
Once the wire acquires rotational velocity, its charges also acquire that velocity and right hand rule says a new Lorentz force, due to velocity of the wire, now
opposes their flow along the wire.
Now, work done against THAT force is a lot different than ohmic heating.
The work done against THAT force is the "back EMF" or "Counter EMF" ,
and its product, Counter-EMF volts X armature amps, IS the electrical energy being converted into
mechanical work not heat.
Now - that's way too brief an introduction to the subject .
You will have to read about electric motors and i advise you to get a few and take them apart.
It helps us to look down the bore and work out force directions by right hand rule...
tor2006 said:
Naturally within the electric motor there are several types of losses I'm interested in your opinion whether I'm right thank you.
Your words did not paint in my mind a clear picture.
But your remarkable improvement in presenting your questions tells me you will persist and refine your understanding .
Lavoisier again :
At the end of the fifth chapter, the Abbé de Condillac adds: "But, after all, the sciences have made progress, because philosophers have applied themselves with more attention to observe, and have communicated to their language that precision and accuracy which they have employed in their observations: In correcting their language they reason better."
I often recommend this article to students. It tells why attention to detail in phrasing our questions and our explanations is so important.
I especially like the paragraph near end that begins with words ""Instead of applying observation to the things we wished to know, we have chosen rather to imagine them...""
Spend the twenty minutes or so it take to read this. It can change your life.
https://web.lemoyne.edu/giunta/lavpref.html
I kept a copy framed over my desk for decades.old jim
