I apologize to the membership for my misguided Zeal.

there are truly good Points... being made here
.....

respectfully
and Back to my Bench

Chet K
PS
for clarity
I am not being "smarmy" here
it is a sincere apology to the members for interrupting useful dialog .

and I hope things can proceed with respect to all "opinions"  .


 

   It only happens in real time,simultaneously,and only the end result is observable.
   Sounds good to me.
          John.

Tinman,

I have always preferred using counter-EMF (CEMF) with regard to inductors and back-EMF (BEMF) with regard to the action of motors.  If used interchangeably, one must be sure to indicate which action is being referred to within the context of its usage. 

From the following Wiki:

https://en.wikipedia.org/wiki/Counter-electromotive_force

PW

PW
I dont see the difference between the two? BackEMF or CounterEMF.
Most everything i read,says the two are one in the same,and mean the same thing-a coil subject to a magnetic field that changes in time.
Quote wiki-The counter-electromotive force (abbreviated counter EMF, or CEMF),[1] also known as the back electromotive force, is the voltage, or electromotive force, that pushes against the current which induces it.

I do realize that the DC motors i used will have the coils(windings) see two changing magnetic fields-one self induced,and one from the PMs,but still,is not the same thing happening,as in,the coils will still be subject to a  magnetic field that changes in time?.

What is the outcome between a !Pushing! type DC PM motor,and a !Pulling! type DC PM motor? How dose that effect the terms being used?,and how dose it change the outcome,when both types will work as a generator as well,but each will subject the coils on the rotor to a different PM field.

One must also take care as to !what! PM field the coils are actually subjected to,in regards to the timing of the motor it self. There are a lot of people that dont actually know as to where each !two! coils are,that has the bulk of the current flowing through them,in relation to the two stator magnets(i am using my DC motors as reference,as they are two pole motors-two PMs)

For example here.
1-If we take a simple pulse motor,and we have our inductor producing a !north! field at the rotor end of that inductor,will the inductors CEMF value be changed if we have all the PMs on the rotor with there north field facing out(toward the inductor),so as the motor is a pushing motor,to that if we have all the south fields facing out(toward the inductor),so as the motor is a pulling motor.
We are to assume that the RPM will remain a constant between the two tests.
So what happens now is,one test,the field of the PM will be the same as the induced field,and so opposite that of what the CEMF wants to produce,and one will be the opposite that of the induced field,but the same as what the CEMF wants to produce.

2- Now,if i remove the rotor altogether,and i pulse that inductor with my FG,so as to simulate the switching of the coil to that of when the rotor was in play,will there be any difference in the efficiency or operation of that inductor?
This is something i can do,and have done many times on my bench.
The point being-how much difference do the stator magnets really make to the coils in that DC motor. Have people just decided that it is the stator PMs that are reducing the current flow,due to them(the PMs) being responsible for creating the backEMF,of have they just failed to realize that as the motor increases speed,that the coils are switching faster-much the same as raising the pulse frequency of a pulsed inductor?.


Brad

PW
I dont see the difference between the two? BackEMF or CounterEMF.

Really?

The CEMF of an inductor causes the current to increase from a minimum after T=0

The BEMF of a motor causes the current to decrease from a maximum after T=0 (as the motor's RPM increases)

PW

The fat lady sings.

The fat lady sings.

Does she dance too? 
Cheers

Mmm-interesting.

A question for you all.

Regarding the BackEMF in a DC PM motor,such as the ones i am using in the previous video.
Is the bulk of the BackEMF a result of the PMs,or a result of the rising and falling current in the rotor winding's ?

I will await a day or two,before i post my video showing the result's.

MH-->what do you think?


Brad

display the waveforms on a DSO.  use a single coil to pulse...  a 5V DC pulse can produce a sharp negative voltage of over 580v.  the current as indicated on the DSO can still be positive.


This will have huge implications on the design of Pulse Motors.