Stupid Me

I have tried to figure out the basics of how a motor works for the last 3 years. Actually, the volts, amps, and number of turns
resulting in motor Kv and torque. A couple of weeks ago I watched a video by the kid who designed the Zero motor and he said that the
only thing that causes torque is amps.

http://blog.motorcycle.com/2015/12/10/motorcycle-news/zero-motorcycles-explains-its-patent-pending-z-force-ipm-motor-video/

Then I said wait a minute, every time I increase the voltage to the motor I get more power, but then realized that more volts
'electrical pressure' would cause more amps and therefore more torque. Today I realised that adding more turns to a motors poles
would mean more electrons flowing around the pole causing more torque. I still don't understand the Kv going up and down with
more or less turns but that is coming next. I am slow, but am determined to understand everything I can.

I am thinking now, after I posed the question of motor Kv and the number of turns of the motor, I think the more turns
the more back-EMF or voltage produced by the motor therefore cancelling out the voltage to the motor at a lower RPM.
I think I got it.

Hey Kim,
Your WAY ahead of the general populous in terms of basic understanding.

I am certain there is clear & definable math in the many text's Miles has linked to over the years (I confess I have only skimmed the on-line versions of the few that are online) regarding the geometry & then the electro physics of turns + voltage + current....
(the math puts me to sleep unless I am putting pencil to paper LOL)

There are so many variable's alone in the tooth geometry X selected steel's permeability it is quite daunting to predict a result.
So tools like Emetor & femm are valuable design aids...but a test is worth 1000 simulations.

when you have the AH-HAA! moment(not IF) drop us a line & let us know the easy math 8)
T

It isn't quite right to say that the only thing that causes torque is amps. Torque (in PM motors) is caused by the interaction of the permanent magnet flux with the flux caused by the current flowing in the coils. So torque is proportional to 1) the current, 2) the air gap flux (per magnet pole) and 3) the effective number of turns.

Next: typical ebike controller behavior. :wink:

learningrc said:

It isn't quite right to say that the only thing that causes torque is amps. Torque (in PM motors) is caused by the interaction of the permanent magnet flux with the flux caused by the current flowing in the coils. So torque is proportional to 1) the current, 2) the air gap flux (per magnet pole) and 3) the effective number of turns.

Click to expand...

And dont forget that "Torque" is "Force times effective Radius"..
All the ,..current , flux, and number of turns,..produces is the "Force" part.
The Torque is directly proportional to the air gap radius (rotor diameter).